Systematic Botany (2005), 30(4): pp. 818–833 q Copyright 2005 by the American Society of Plant Taxonomists Resurrection of Genus Kadua for Hawaiian Hedyotidinae (Rubiaceae), with Emphasis on Seed and Fruit Characters and Notes on South Pacific Species EDWARD E. TERRELL,1,3 HAROLD E. ROBINSON,1 WARREN L. WAGNER,1 and DAVID H. LORENCE2 Department of Botany, NHB 166, P. O. Box 37012, Smithsonian Institution, Washington, D.C. 20013-7012; 2 National Tropical Botanical Garden, 3530 Papalina Road, Kalaheo, Kauai, Hawaii 96741 3 Author for correspondence. Present address: 14001 Wildwood Dr., Silver Spring, Maryland 20905 (terr60@ msn.com) 1 Communicating Editor: Paul S. Manos ABSTRACT. We examined shapes and surface features of seeds of 19 species of Hawaiian Hedyotideae using scanning electron microscopy. The study concentrates on the Hedyotideae previously recognized in the genus Hedyotis and here recognized as the genus Kadua, lacking diplophragmous capsules, and having salverform, fleshy corollas with appendaged lobes. The seeds fell into four main morphological groups: (1) hat- or fan-shaped, laterally cuneate, compressed seeds (Kadua subg. Kadua and atypical species of Gouldiopsis and Wiegmannia); (2) ovoid or elliptic seeds with conspicuous bubble-shaped bodies included in the areoles (cells) (most of sect. Wiegmannia); (3) flat broadly winged seeds with a lateral hilum attached at wing margin (Kadua centranthoides, type species of sect. Gouldiopsis); (4) brick-like or blocky seeds with a centric ventral hilum (Kadua subg. Gouldia). The results of the seed study correlate with the taxonomic arrangement in the current Hawaiian flora. An appendix lists the Kadua names including necessary new combinations and their Hedyotis synonyms for the Hawaiian taxa and seven additional South Pacific taxa having the same corolla characters. The following new names are published: Kadua subg. Gouldia (A. Gray) W. L. Wagner & Lorence, Kadua sect. Gouldia (A. Gray) W. L. Wagner & Lorence, Kadua fosbergii (W. L. Wagner & D. R. Herbst) W. L. Wagner & Lorence, Kadua axillaris (Wawra) W. L. Wagner & Lorence, Kadua sect. Phyllozygia (W. L. Wagner & Herbst) W. L. Wagner & Lorence, Kadua tryblium (D. R. Herbst & W. L. Wagner) W. L. Wagner & Lorence, Kadua sect. Oceanica (Fosberg) W. L. Wagner & Lorence, Kadua sect. Austrogouldia (Fosberg) W. L. Wagner & Lorence, Kadua lucei (Lorence & J. Florence) W. L. Wagner & Lorence, Kadua nukuhivensis (J. Florence & Lorence) W. L. Wagner & Lorence, Kadua tahuatensis (Lorence & J. Florence) W. L. Wagner & Lorence, Kadua grantii (Fosberg) W. L. Wagner & Lorence, Kadua sect. Protokadua (Fosberg) W. L. Wagner & Lorence, Kadua coriacea (J. E. Smith) W. L. Wagner & Lorence, Kadua sect. Gouldiopsis (Fosberg) W. L. Wagner & Lorence, Kadua foggiana (Fosberg) W. L. Wagner & Lorence, Kadua sect. Wiegmannia (Meyen) W. L. Wagner & Lorence, Kadua cordata Cham & Schltdl. subsp. remyi (Hillebr.) W. L. Wagner & Lorence, Kadua cordata Cham & Schltdl. subsp. waimeae (Wawra) W. L. Wagner & Lorence, Kadua degeneri (Fosberg) W. L. Wagner & Lorence, Kadua degeneri (Fosberg) W. L. Wagner & Lorence subsp. coprosmifolia (Fosberg) W. L. Wagner & Lorence, Kadua elatior (H. Mann) W. L. Wagner & Lorence, Kadua flynnii (W. L. Wagner & Lorence) W. L. Wagner & Lorence, and Kadua st.-johnii (B. C. Stone & Lane) W. L. Wagner & Lorence. The tribe Hedyotideae Cham. & Schltdl. ex DC. includes herbaceous or shrubby rubiaceous genera having few to many seeds per capsule. The subtribe Hedyotidinae DC., as originally described (Candolle 1830), included (among other genera) Hedyotis with 28 species and Oldenlandia with 45 species. The genus Hedyotis has been a source of taxonomic problems for many years (Terrell 1996). Previous studies of the tribe Hedyotideae (Rubiaceae) have focused mainly on the North American representatives (Terrell et al. 1986, Terrell 1996 on Houstonia, inter alia). These studies have emphasized seed characters, which have been used in a limited way in many older classifications of the Rubiaceae, and chromosome numbers, which are unusually variable in the tribe compared to most of the family. A recent study (Terrell and Robinson 2003) of the Asian and Micronesian relatives of the type species of Hedyotis, H. fruticosa L., included all characters in establishing a base line for comparison of subgenus Hedyotis, or Hedyotis sensu stricto, with other species. Recent molecular studies (Bremer 1996; Bremer and Manen 2000) showed that genera of the tribe Spermacoceae are nested within the tribe Hedyotideae; however, when the two tribes are united, the older name Spermacoceae must be used following the rules of priority (Greuter et al. 2000). Terrell and Wunderlin (2002) found basic differences in the seed and fruit morphology of the two tribes, consequently we prefer to maintain the two tribes as distinct, with tribe Hedyotideae treated here in the more traditional sense. Andersson et al. (2002), in a molecular study of the South American genus Arcytophyllum Willd. ex Schult., included four species of Hawaiian Hedyotis among many Hedyotideae-Spermacoceae genera. They noted that the four species (H. degeneri, H. hillebrandii, H. parvula, and H. schlechtendaliana) formed a clade within the Spermacoceae sens. lat. (including Hedyotideae), with H. hillebrandii sister to the three other species. Preliminary molecular data (Motley et al. 1998; Motley 2003) suggested that (1) Hawaiian Hedyotis resulted from a single colonization, (2) the Hawaiian species are divided into two clades, one with fleshy fruits and the other with dry fruits. The present investigation of Hawaiian species of Hedyotideae continues use of scanning electron microscopy (SEM) in studying seed and fruit characters and provides additional data on inflorescence and corolla characters. The study shows that the seeds of the 818 2005] TERRELL ET AL.: HAWAIIAN HEDYOTIDINAE 819 TABLE 1. Collections of Hawaiian Kadua species examined in this study, with Hedyotis names in synonymy. Kadua acuminata Cham. & Schltdl. (Hedyotis acuminata (Cham. & Schltdl.) Steudel): Flynn & Bergau 1361 (PTBG), Hawaii, SEM B2; Degener 11694 (US), Oahu, SEM B24; Herbst 3073 (US), Oahu; Fosberg 10783 (US), SEM R30. K. affinis DC. (H. terminalis (Hook. & Arn.) W. L. Wagner & D. R. Herbst). Chapin s.n. (NTBG 910714), Kauai, SEM B4; Degener 12732 (US), Oahu; Perlman et al. 15353 (PTBG), Maui. K. axillaris (Wawra) W. L. Wagner & Lorence (H. hillebrandii (Fosberg) W. L. Wagner & D. R. Herbst). Wagner et al. 5870 (PTBG), Maui, SEM B13. K. centranthoides Hook. & Arn. (H. centranthoides (Hook. & Arn.) Steudel). Terrell & Terrell 5503 (US), Hawaii, SEM H36; Kiehn (NTBG-900593), Kauai, SEM B22; Henrickson 4061A (US); Degener & Greenwell 21916 (US); Perlman et al. 10499 (PTBG), Hawaii. K. cookiana Cham. & Schltdl. (H. cookiana (Cham. & Schltdl.) Steudel). Cult. (NTBG 950509), Kauai, SEM B23. K. cordata Cham. & Schltdl. (H. schlechtendaliana Steudel). Wood 1399 (PTBG), Kauai, SEM B19; Wood 3643 (US), Kauai, SEM B44. K. degeneri (Fosberg) W. L. Wagner & Lorence (H. degener Fosberg). Wood 3432 (US), Oahu, SEM B25. K. elatior (H. Mann) W. L. Wagner & Lorence (H. elatior (H. Mann) Fosberg). Perlman 12003 (PTBG), Kauai, SEM B10; Christenson 63 (US), Kauai, SEM B27. K. fluviatilis C. N. Forbes (H. fluviatilis (C. N. Forbes) Fosberg). Perlman 11293 (PTBG), Kauai, SEM B16. K. flynnii (W. L. Wagner & Lorence) W. L. Wagner & Lorence (H. flynnii W. L. Wagner & Lorence). Wood 1204 (PTBG), Kauai, SEM B5. K. foggiana (Fosberg) W. L. Wagner & Lorence (H. foggiana Fosberg). Lorence et al. 5324 (PTBG), Kauai, SEM B12; Degener & Greenwell 21637 (US), Kauai, SEM B28. K. formosa Hillebr. (H. formosa (Hillebr.) Fosberg). Wood et al. 3943 (PTBG), Maui, SEM B9, B29. K. fosbergii (W. L. Wagner & D. R. Herbst) W. L. Wagner & Lorence (H. fosbergii W. L. Wagner & D. R. Herbst). Fosberg 12374 (US), Lanai, SEM B18. K. knudsenii Hillebr. (H. knudsenii (Hillebr.) Fosberg). Degener 12643 (US), Kauai, SEM H65, B26. K. laxiflora H. Mann (H mannii Fosberg). Degener 11726 (US), Molokai, SEM H66. K. littoralis Hillebr. (H. littoralis (Hillebr.) Fosberg). Perlman 11202 (NTBG), Molokai, SEM B15; Forbes 526 (US), Molokai. K. parvula A. Gray (H. parvula (A. Gray) Fosberg). Perlman 14665 (PTBG), Oahu, SEM B11; Degener 12808 (US), Oahu. K. st.-johnii (B. C. Stone & Lane) W. L. Wagner & Lorence (H. st.-johnii B. C. Stone & Lane). Perlman & Wood 13331 (PTBG), Kauai, SEM B21. K. tryblium (D. R. Herbst & W. L. Wagner) W. L. Wagner & Lorence (H. tryblium D. R. Herbst & W. L. Wagner). Perlman 11675 (NTBG), Kauai, SEM B8. Hawaiian species are distinct from Asian and Pacific species of Hedyotis subgenus Hedyotis and from North American species of Hedyotidae, and we resurrect the oldest genus name, Kadua, for these species. MATERIALS AND METHODS Seeds were supplied by D. H. Lorence from specimens in the herbarium of the National Tropical Botanical Garden (PTBG), and additional seeds were obtained by the first author from the US herbarium (Table 1). Seeds were examined by dissecting microscope and data were recorded on a computerized form. Mature well-formed seeds from capsules and dried formerly fleshy fruits were examined by scanning electron microscopy (SEM) by Terrell and Robinson at the Smithsonian Institution. These data supplemented earlier SEM work on the seeds of many collections of species of the tribe Hedyotideae (sensu Terrell and Wunderlin 2003) carried out at the Smithsonian Institution by Terrell and Robinson and by Terrell at the U. S. Department of Agriculture at Beltsville, Maryland prior to 1985. During this earlier work, two of the Hawaiian species, Hedyotis acuminata and H. centranthoides, had been examined. Table 1 lists the mature-seeded collections of the species examined and those treated by SEM, and includes Kadua and Hedyotis nomenclatural authors and collection data. Table 2 provides important seed data for selected groups of species, and Table 3 does the same for fruit and capsule characters. Table 4 compares data for selected inflorescence and corolla characters. Appendix 1 summarizes Kadua names and lists new combinations for Hawaiian species and seven South Pacific species. The Hawaiian species are described here and in Table 2 according to the following seed characters: Length and width or diameter, thickness, compression type, compression extent, shape type, whether laterally cuneate, whether broadly winged, hilum wheth- er centric or at margin, hilum type or size, testa surface, areoles (cells) shape, presence/absence of included bodies, areole walls thickness and whether they have projections. The compression type refers to whether the hilum is located on or near the center of the ventral face or along the margin of the seed; if centric (central) it is considered a dorsiventrally compressed seed; if marginal it is considered to be laterally compressed. With the exception of the sect. Gouldia, seeds of the Hawaiian species have lateral hila, and differ from seeds of other genera of Hedyotideae which are centric. In the hat- or fan-shaped seeds of the subg. Kadua the seeds are strongly compressed, thinner near the marginal hilum and thicker at the opposite end, a condition termed laterally cuneate. Fruit characters (Table 3) are mainly length and width or diameter, shape, structure or texture, and endocarp sclerification. If endocarp sclerification is strong, the term woody may apply. The term disk apex (in text) refers to whether the apex of the capsule is truncate, raised, beaked, or depressed. Dehiscence is not included in Table 3, as all taxa except sect. Gouldia have capsules with initial loculicidal dehiscence, followed later in maturity by septicidal dehiscence. In sect. Gouldia the fruits are fleshy and indehiscent. PACIFIC HEDYOTIDEAE WITH TAXONOMIC NOTES The Hedyotideae of the Pacific that have been treated by Fosberg (1943) and Wagner et al. (1999) include three groups of species. The first of these groups treated by Wagner et al. (1999) among the Hawaiian species of Hedyotis include the pantropical weed Oldenlandia corymbosa L., the type species of Oldenlandia L., and Oldenlandiopsis callitrichoides (Griseb.) Terrell & W. H. 820 dorsiventral brick-like/blocky no no centric 0.3–0.7 diam. none lateral flat; suborbicular/oval no yes marginal punctiform none not apparent ellipsoid, ovoid no no surface punctiform large, bubble-like lateral hat-shaped/irreg.angulate yes no marginal punctiform small, oval, smooth/wrinkled Compression type Shape type/outline Laterally cuneate? Broad wing? Hilum location Hilar area Testa/Areole inclusions lateral hat-or fan-shaped yes no marginal punctiform embedded papillae Seed group 2 Wiegmannia Seed group 1, subg. B Kadua Seed group 1, subg. A Kadua TABLE 2. Seed characters for seed groups. Seed group 3 Gouldiopsis: K. centran. Seed group 4 Gouldia, Phyllozygia SYSTEMATIC BOTANY [Volume 30 Lewis (Terrell and Lewis 1990), the type of Oldenlandiopsis Terrell & W. H. Lewis. The latter was originally endemic to the West Indies, but occurs on O’ahu and Maui as a rare adventive species. Oldenlandia subg. Oldenlandia includes small herbs with small flowers and capsules; seeds trigonous, very small, usually 0.2– 0.5 mm long and 50–100 or more per capsule; chromosome number n 5 9. The genus Oldenlandia has a worldwide distribution of about 100 species and an African center of distribution and diversity (see taxonomic notes in Terrell and Robinson 2003). The second group involves the Hedyotis species related to H. fruticosa L., the type species of Hedyotis (Terrell and Robinson 2003). This Asian and Micronesian group is Hedyotis sensu stricto, and can be summarized nomenclaturally as follows: Hedyotis L., Gen. Pl. ed. 5, 44 (1754). Lectotype species: Hedyotis fruticosa L. Hedyotis subgenus Hedyotis. Hedyotis sect. Diplophragma Wight & Arn., Prodr. florae Peninsulae orientalis 1:405–418 (1834). Lectotype: Hedyotis fruticosa L. The species of Hedyotis subgenus Hedyotis (Terrell and Robinson 2003) have seeds that are rather strongly dorsiventrally compressed, with an apical centric hilum on a conspicuous, elevated, ventral, hilar ridge. The capsules are termed diplophragmous, an old term referring to their splitting into two separate cocci each with a median slit opening into a locule. This primarily septicidal dehiscence is usually preceded by a partial apical loculicidal dehiscence. The third group includes the Hawaiian and some other Polynesian species. It is these species that are the principle subject of study in this paper. Hawaiian Taxa of Hedyotideae. The generic, subgeneric, and sectional names that are available for the native group of Hedyotideae in Hawaii are as follows, with the principal names arranged in chronological order. Kadua Cham. & Schltdl., Linnaea 4: 157. 1829.—Type: Kadua acuminata Cham. & Schltdl. Hedyotis subg. Kadua (Cham. & Schltdl.) Fosberg, Bernice P. Bishop Mus. Bull. 174: 69. 1943. Wiegmannia Meyen, Reise 2: 139. 1835.—Type: Wiegmannia glauca Meyen, non Hedyotis glauca W. W. Smith 5 Hedyotis schlechtendaliana Steud. 5 Kadua cordata Cham. & Schltdl. Hedyotis sect. Wiegmannia (Meyen) Fosberg, Bernice P. Bishop Mus. Bull. 174: 29. 1943. Gouldia A. Gray, Proc. Amer. Acad. Arts 4: 310. 1860.— Lectotype: Gouldia sandwicensis A. Gray, nom. illeg. 5 Hedyotis terminalis (Hook. & Arn.) W. L. Wagner & Herbst. 5 Kadua affinis DC. Hedyotis sect. Gouldia (A. Gray) W. L. Wagner & Herbst in W. L. Wagner, Herbst and Sohmer, Occas. Pap. Bernice P. Bishop Mus. 29: 111. 1989. 2005] 821 TERRELL ET AL.: HAWAIIAN HEDYOTIDINAE TABLE 3. Fruit/capsule characters for selected taxa. Shape Subg. Kadua, subgroup A Subg. Kadua, subgroup B: four species Subg. Kadua, subgroup B: K. formosa Sect. Wiegmannia: five species Sect. Wiegmannia: K. littoralis Sect. Wiegmannia: K. st.-johnii Sect Gouldiopsis: K. centranthoides Sects. Gouldia, Phylllozygia turbinate/subglobose turbinate/subglobose ellipsoid-cylindrical turbinate/subglobose obconical sublenticular subglob./turbinate/obovoid globose Hedyotis subg. Polynesiotis Fosberg, Bernice P. Bishop Mus. Bull. 174: 22. 1943.—Type: Wiegmannia glauca Meyen 5 Kadua cordata Cham. & Schltdl. (by inclusion of Wiegmannia Meyen in synonymy). Polynesiotis has priority at subgeneric level, Wiegmannia has priority at generic and section levels. Hedyotis sect. Bikkiocarpa Fosberg, Bernice P. Bishop Mus. Bull. 174: 25. 1943.—Type: Kadua formosa Hillebr. Hedyotis sect. Gouldiopsis Fosberg, Bernice P. Bishop Mus. Bull. 174: 56. 1943.—Type: Hedyotis centranthoides (Hook. & Arn.) Steud. Hedyotis sect. Protokadua Fosberg, Bernice P. Bishop Mus. Bull. 174: 23. 1943.—Type: Hedyotis coriacea J. E. Smith (by monotypy). Hedyotis sect. Phyllozygia W. L. Wagner & Herbst in W. L. Wagner, Herbst, and Sohmer, Occas. Pap. B ernice P. Bishop Mus. 29: 112. 1989.—Type: Hedyotis tryblium Herbst & W. L. Wagner in W. L. Wagner, Herbst, and Sohmer (1989). These elements were disposed in the following way by Fosberg (1943) in his study of the Polynesian Hedyotis. He held a broad view of the genus, but excluded Gouldia by placing it in a separate genus (Fosberg 1937). He commented (Fosberg 1943: 14) that subgenera are the main evolutionary lines in the genus Hedyotis, and stated that ‘‘Many botanists would regard these groups as genera.’’ He subdivided Hedyotis into five subgenera: Oldenlandia, Diplophragma, Kadua, Oceanica, and Polynesiotis. In Polynesiotis he included five sections: Wiegmannia, Protokadua, Gouldiopsis, Bikkiocarpa, and Austrogouldia. Of these, Austrogouldia Fosb., Diplophragma Wight & Arn. (5 typical Hedyotis), and Oceania Fosb. (based on Coprosma oceania W. R. B. Oliver) are not Hawaiian. In dealing with the taxonomy of the Hawaiian species of Hedyotis, we were guided by Wagner et al.’s (1990, 1999) treatments in the manuals of the Hawaiian flora, which updated Fosberg’s nomenclature and taxonomy, making several changes to the infrageneric taxa. They recognized subgenera Oldenlandia (see above), Kadua, and Polynesiotis Fosberg. Under Polynesiotis they included sections Gouldia (A. Gray) W. L. Wagner & Herbst, Phyllozygia W. L. Wagner & Herbst, Structure/texture str.quadrangular or winged not quadrangular/grooved not quadrangular not quadrangular not quadrangular not quadrangular strongly grooved fleshy Wiegmannia (Meyen) Fosberg, Protokadua Fosberg, Bikkiocarpa Fosberg, and Gouldiopsis Fosberg. The Hawaiian flora lists 20 species of Hedyotis (excluding Oldenlandia and Oldenlandiopsis). An additional species, H. flynnii, was described recently by Wagner and Lorence (1998). Two species, Hedyotis coriacea Sm. and H. foliosa (Hillebr.) Fosberg, are rare or extinct, respectively, and no seeds were available. Nineteen species, all endemic to the Hawaiian Islands, provided seeds for this study. Seventeen of the species are shrubs, subshrubs, or small trees up to 5 m, and two other species (H. littoralis, H. st.-johnii) are large succulent perennial herbs. Following the recent more precise delimitation of typical Hedyotis (Terrell and Robinson 2003), a decision has been made by the authors that affects the generic treatment in the present study. The diplophragmous capsules with paired cocci in typical Hedyotis are lacking in the Hawaiian Hedyotideae and related South Pacific species, which have salverform, fleshy, longtubed, and appendaged corollas. This definable grouping of Pacific Hedyotideae is recognized here under the oldest available and applicable generic name, Kadua. The names of the Kadua species are summarized in Appendix 1 (prepared by Wagner and Lorence). Gouldia, which is also readily definable by its fleshy fruits, is only one element of the broader natural group as shown by molecular sequence studies (Motley et al. 1998), and the paraphyletic non-Gouldia remnant has no defining morphological characters, but could conceivably be subdivided into three or more separate groups, largely corresponding to the recognized sections. The broader concept is favored here with the assumption that accelerated evolutionary diversification has occurred in the group as it has in many other island taxa. This broader group of species forms an easily recognized group. RESULTS Seeds of the Hawaiian species of Kadua fall into four groups as outlined in Table 2. Results for the fruit morphology are given in Table 3. These seed and fruit results are described below in more detail and pertinent SEM micrographs are referenced. The Kadua names are 822 Sect. Gouldia (3 spp.) Sect. Gouldiopsis (3 ssp.) terminal paniculate/thyrsoid no weakly inflexed strongly quadrangular. not depressed terminal paniculate/thyrsoid no inflexed not quadrangular. depressed Sect. Wiegmannia (9 spp.) Subg. Kadua A (2 spp.) axillary 1 (-7) flowers yes inflexed not quadrangular depressed Inflorescence position Inflor. type (all cymose) Peduncles adnate to stem? Corolla buds: lobes Corolla buds: limbs Corolla buds: apices TABLE 4. Inflorescence and corolla characters for selected taxa. terminal paniculate no not inflexed weakly quadrangular. not depressed SYSTEMATIC BOTANY [Volume 30 adopted in accord with our previous decision (see previous section) to recognize the species under the genus Kadua. Hedyotis synonyms are added if their epithets under Kadua are different. Nomenclature authorities are given in Table 1. Seed and fruit characters are described in the Materials and Methods. Our results partly coincide with the subgenera and sections recognized by Fosberg (1943) and Wagner et al. (1999). For comparison of the seed results with Wagner et al.’s (1999) taxonomic arrangement of the Hedyotis species we list an outline of their arrangement, as follows, with mention of some correlated characters. Hedyotis subg. Kadua: two species: H. acuminata and H. fluviatilis. Hedyotis subg. Polynesiotis: seventeen species in the following sections: sect. Wiegmannia (H. cookiana, H. degeneri, H. elatior, H. flynnii, H. littoralis, H. mannii, H. parvula, H. st.-johnii, H. schlechtendaliana); sect. Bikkiocarpa (H. formosa); sect. Gouldiopsis (H. centranthoides, H. foggiana, H. knudsenii); sect. Gouldia and Phyllozygia (H. fosbergii, H. hillebrandii, H. terminalis, H. tryblium). Seed Group 1. Subgenus Kadua sens. str. The typical subgroup A includes two closely related species, Kadua acuminata and K. fluviatilis, of which the former (Fig. 1A–D) is the main representative species. The following description includes both species (Tables 2, 3): Seeds 0.5–1.3 3 0.4–0.8 mm, compression lateral, moderate or strong, hat-shaped or fan-shaped (Fig. 1A, B, E), or irregularly angulate, laterally cuneate with thinner area at apex (Fig. 1A, B, E), hilum marginal, punctiform on the thinner margin, testa with embedded papillae (Fig. 1C, D, F), areoles polygonal, walls thick, sometimes with small jagged projections. Capsules 6– 13 3 5–13 mm, turbinate to subglobose, strongly quadrangulate or winged, woody, disk raised. Kadua fluviatilis seeds resemble K. acuminata seeds but are less compressed, less angulate (Fig. 1E–F). The two species of this typical subgroup have the following three important non-seed characters: peduncles adnate or partly adnate to the stem, flowers 1–7 in axillary inflorescences, and capsules woody (Fosberg 1943, Wagner et al. 1999). Seed group 1 subgroup B includes five additional species: Kadua degeneri and K. elatior from sect. Wiegmannia; K. foggiana and K. knudsenii from sect. Gouldiopsis; and K. formosa from sect. Bikkocarpa (Figs. 2, 3). The composite description of seeds of this group is as follows (Table 2): Seeds 0.4–1.0 3 0.3–0.8 mm, compression lateral, slight to strong, seeds hat- or fanshaped (Fig. 2E, F) or irregularly angulate (Fig. 2A; Fig. 3A, C), laterally cuneate (Fig. 2C, F), hilum punctiform, marginal, testa usually smooth, areoles rounded or polygonal, enclosing small, oval (Fig. 2 B, D), sometimes wrinkled bodies (Fig. 3B, D), walls thin or in K. knudsenii rather thick. (Fig. 3 D). Capsules smaller 2005] TERRELL ET AL.: HAWAIIAN HEDYOTIDINAE 823 FIG. 1. Seeds of Kadua subg. Kadua sect. Kadua subgroup A, examined by SEM. A-D. Kadua acuminata. A. Side view with hilum at seed apex (sample B24). B. Side view (sample B2). C, D. Enlargement of areoles (sample B24). E, F. K. fluviatilis (sample B16), E. Side view. F. Enlargement of areoles. Collections data in Table 1. than in subgroup A, except in K. formosa, which are ellipsoid (listed separately in Table 3). The subgroup B species resemble the typical subgroup A in having seeds hat- or fan-shaped and laterally cuneate, but differs mainly in having small oval bodies in the areoles, with testa lacking embedded papillae and lacking any projections. This subgroup was earlier in this study considered to be intermediate, however, it is included here in the first subgroup because the hat- or fan-shaped seeds are similar in shape to subgroup A although smaller. The oval bodies in the areoles are unlike the areolar bodies in Group 2 (see below). We conclude that the general seed shape in the two species in subgroup A and five species in subgroup B represent a form basic to the subgenus Kadua. 824 SYSTEMATIC BOTANY [Volume 30 FIG. 2. Seeds of Kadua subg. Kadua subgroup B, examined by SEM. A, B. Kadua degeneri (sample B25). A. Side view with hilum at seed apex. B. Enlargement of areoles. C, D. K. elatior (sample B27). C. Side view, D. Enlargement of areoles. E, F. K. foggiana (sample B28), side views. Collections data in Table 1. Seed Group 2. Section Wiegmannia. There are seven species in this group: K. cookiana, K. cordata (H. schlechtendaliana), K. flynnii, K. laxiflora (H. mannii), K. littoralis, K. parvula, K. st.-johnii. The characteristics of these species are outlined as follows (Table 2): Seeds 0.2–0.8 3 0.2–0.5 mm, compression presumed lateral, but not apparent, slight or moderate, ellipsoid, ovoid, or obtusely angulate, hilum punctiform, inconspicuously attached on the rounded seed surface, areoles rounded or irregularly polygonal, each areole enclosing a bubble-like body, areole walls thin (Figs. 4, 5). Unique features are the ellipsoid or ovoid shape, hila inconspicuously attached on the rounded seed surface, and presence of one bubble-like body per areole (best seen in mature seeds of K. cordata in Fig. 4A,B and K. flynnii in Fig. 5A,B). The bubble- like bodies, perhaps also describable as large papillae and to some extent visible at relatively low power, occur in all of the seven species (six species illustrated in Figs. 4, 5), and are a prominent surface feature not present in other Kadua groups. The capsules (Table 3) of five of the species are as follows: 2–6 3 3–7 mm, turbinate to subglobose, thinly to strongly sclerified, disk raised, flat, or conical or beaked. Kadua littoralis has capsules somewhat different: 6–10 3 5–9 mm, obconical, slightly sclerified, and disk slightly raised. This capsule is more widely expanded at its apex than any other species in the genus. A seventh species, K. st.-johnii, needs future study. Its sublenticular capsules (Table 3) are very short and very wide (2.5–3 3 7–8 mm), and have a ‘‘squashed’’ appearance, certainly the oddest capsules of any of the 2005] TERRELL ET AL.: HAWAIIAN HEDYOTIDINAE 825 FIG. 3. Seeds of Kadua subg. Kadua subgroup B, examined by SEM. A, B. Kadua formosa (sample B29). A. Side view with hilum at seed apex. B. Enlargement of areoles. C, D. K. knudsenii (sample B26). C. Side view. D. Enlargement of areoles. Collections data in Table 1. Kadua species. On the other hand, its seeds (Fig. 4E, F) appear generally similar to other group 2 species, although slightly smaller. Kadua littoralis (Fig. 4C, D), similar to K. st.-johnii only in being a perennial herb, is shown for comparison with the latter. As noted previously, two additional species, K. degeneri and K. elatior, recognized by Wagner et al. (1999) as members of sect. Wiegmannia, are placed by us in seed group 1 subgroup B. Seed Group 3. Section Gouldiopsis. This group includes three species, Kadua centranthoides, K. foggiana, and K. knudsenii. The last two of these differ distinctly in seed characters from the first species, and have been placed by us in seed group one. The composite section Gouldiopsis is discussed further in the Discussion. The following seed description is based on eight studied collections of the type species of the section, K. centranthoides (Fig. 6). Seeds 0.7–1.2 3 0.5–1.1 mm, thin, compression lateral, strong, seeds flat, in outline orbicular, elliptical, or oval, central body (excluding wing) usually ca. 0.5–0.6 mm diam, more or less orbicular, wing 0.1–0.3 mm wide, wing margin entire or irregularly undulate, hilum marginal, punctiform on wing margin (Fig. 6A, B), testa surface appearing minutely roughened, areole walls thin, central body of seed with radially elongate areoles extending outward to the punctiform hilum, the remaining areoles irregularly angulate with sinuous walls (Fig. 6). Capsules 3–5 3 3.5–7 mm, subglobose to turbinate, obconic, or obovoid, slightly compressed, strongly grooved, somewhat sclerified, disk truncate or slightly raised (Table 3). The seeds of the type species of the section, Kadua centranthoides, are unique (Fig. 6A–D). They are flat and thin, surrounded by a broad wing, and with a punctiform hilum attached at the wing margin. Although the vegetative parts of the plants do not seem to differ conspicuously from other species, the seeds are quite different from all other Kadua seeds. Functionally the Kadua centranthoides seed type would seem ill-adapted, with the developing wing severing the vascular trace furnishing nutrition to the seed. However, the wing is evidently late in developing or otherwise not a problem since the species is very successful and distributed on all the main islands except Ni’ihau and Kaho’olawe. A chromosome number of 2n 5 ca.100 was listed for K. centranthoides from Hawaii by Skottsberg (1955); Wagner et al. (1999) commented that this report needs to be confirmed. Seed Group 4. Sections Gouldia, Phyllozygia. These plants occur on the main islands and include three similar species: Kadua fosbergii, K. axillaris (H. hillebrandii), and K. affinis (H. terminalis), the last one being the most common and widespread species. The plants have fleshy fruits and unique seeds (Fig. 7A– D). The section Phyllozygia, based on Kadua tryblium 826 SYSTEMATIC BOTANY [Volume 30 FIG. 4. Seeds of Kadua subg. Kadua sect. Wiegmannia, examined by SEM. A, B. Kadua cordata (sample B44). A. Whole seed. B. Enlargement of areoles. C, D. K. littoralis (sample B15). C. Whole seed. D. Enlargement of areoles. E, F. K. st.-johnii (sample B21). E. Whole seed. F. Enlargement of areoles. Collections data in Table 1. and occurring only in Kauai, is similar to section Gouldia in its seeds (Fig. 7E, F) and fruits, but differs in four vegetative characters from the other species (Wagner et al. 1990, 1999). Gouldia was treated as a distinct genus by Fosberg (1937), however, Wagner et al. (1989, 1999) reduced it to a section of Hedyotis distinguished by several characters including the fleshy fruit. Chromosome numbers (2n) reported by Skottsberg (1955) were as follows: Gouldia axillaris Wawra from Molokai, ca. 72; Gouldia cf. ovata (Wawra) Skottsberg (5 2005] TERRELL ET AL.: HAWAIIAN HEDYOTIDINAE 827 FIG. 5. Seeds of Kadua subg. Kadua sect. Wiegmannia, examined by SEM. A, B. Kadua flynnii (sample B5). A. Whole seed. B. Enlargement of areoles. C, D. K. laxiflora (sample H66). C. Whole seed. D. Enlargement of areoles. E, F. K. parvula (sample B11). E. Whole seed. F. Enlargement of areoles. Collections data in Table 1. K. affinis) from Maui, ca. 102, 104; Gouldia spp. from Maui, Hawaii, and Lanai, ca. 93, 95–105. It is difficult to judge the significance of these numbers until more chromosomal data become available. The seed data for both sections (Fig. 7) are combined here in one common description: Seeds 0.5–2.0 3 0.4– 1.7 3 0.3–0.8 mm, thicker than other Hawaiian Hedyotidineae seeds, compression dorsiventral, moderate or strong, irregularly brick-like, blocky, or angulate (Fig.7A, C, E), irregularly polygonal, dorsal face convex to flat, ventral face slightly concave, hilum centric, with a circular or elliptical area ca 0.3–0.7 mm diam., 828 [Volume 30 SYSTEMATIC BOTANY FIG. 6. Seeds of Kadua centranthoides (sect. Gouldiopsis), examined by SEM. A. Flat, broadly winged seed (Sample B22). B. Marginal winged hilar area (Sample B22). C. Flat, broadly winged fragile seed (sample H36). D. Enlargement of areoles (Sample B22). Collections data in Table 1. testa appearing fibrous, often with marginal loosely attached cells (Fig. 7C), areoles small, round or polygonal, their walls thick, fibrous. The fruits are 4–12 mm diam., globose, fleshy, indehiscent, biloculate by a central septum, becoming dry with age. Fosberg (1937, pp. 25, 27, fig. 1), described them as dark blue or purplish black, crowned with a circular area having four tiny remote calyx teeth and containing 4–40 or more seeds having axile placentation near the midpoint of the septum, with an embryo straight or nearly so. Our observations of dried fruits broken manually showed an outermost blackish thick layer surrounding an inner brownish-yellow thinner hard layer. Seeds are tightly pressed together with the dorsal face outward against the hard inner layer and the opposite ventral face having a roundish hilar area faced peltately against the placentae. This compression causes great variation in seed shape. The seeds and fruits of sections Gouldia and Phylloz- ygia (see Discussion) differ strongly from those of the other taxa and, following Fosberg (1937), could suggest recognition as a genus. DISCUSSION Four main seed types occur in the Hawaiian species: (1) seeds moderately or strongly compressed, hat- or fan-shaped, laterally cuneate, with marginal hilum (subg. Kadua); (2) seeds ellipsoid or ovoid with inconspicuous hilar attachment on rounded surface and bubble-like areolar inclusions (sect. Wiegmannia), (3) seeds flat, broadly winged, with the hilum on the wing margin (K. centranthoides); (4) seeds brick-like, thickened, with central hilum (Sect. Gouldia). These seed types are unique to the Hawaiian species. They differ from those of Oldenlandia subgenus Oldenlandia by the fewer and larger seeds that are not 3-angled. Other hedyotoid genera indig- 2005] TERRELL ET AL.: HAWAIIAN HEDYOTIDINAE 829 FIG. 7. Seeds of Kadua subg. Gouldia, examined by SEM. A, B. Kadua affinis (sample B4) A. Ventral face showing central hilar area. B. Enlargement of areoles. C, D. K. fosbergii (sample B18). C. Ventral face with central hilar area. D. Enlargement of areoles. E, F. K. tryblium (sample B8). E. Ventral face with small hilar area. F. Enlargement of areoles. Collections data in Table 1. 830 SYSTEMATIC BOTANY enous to other parts of the world, e.g., Houstonia, Bouvardia, Arcytophyllum, Manettia, Neanotis, Stenaria, and Stenotis, variously differ in part by having a centric hilum with or without a hilar ridge or a concave ventral face. Of these, the neotropical genera Bouvardia and Manettia differ particularly by the broad wings with a centric hilum, instead of the marginal hilum of Kadua centranthoides. The Hawaiian species have four corolla characters in common. The corollas are fleshy, salverform, with [Volume 30 appendaged lobes, and with long, narrow corolla tubes usually 2–4 times longer than their lobes. With addition of the seed and fruit characters already discussed, strong support is seen for generic status for the native Hawaiian Hedyotideae. We resurrect the genus Kadua, the oldest genus name that refers to the Hawaiian species, to replace the name Hedyotis. Appendix 1 lists the Kadua names and their synonyms, and also includes seven South Pacific species that have the four corolla characters described above. Key to Seed and Capsule Groups of Hawaiian Taxa 1. Seeds thick, brick-like or blocky; hilum centric with a small ventral circular area; fruits fleshy. . . . . . . . . Group 4. Sect. Gouldia 1. Seeds not brick-like; hilum punctiform, located on margin of seed or attached at a point on a rounded seed; fruits are capsules, not fleshy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Seeds with a broad papery wing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Group 3. Kadua centranthoides 2. Seeds lacking a wing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. Seeds ellipsoid, ovoid, or obtusely angulate; not cuneate; hilum punctiform, attached on the rounded seed, areoles each with a bubble-like inclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Group 2. Sect. Wiegmannia 3. Seeds hat- or fan-shaped, or irregularly angulate, laterally cuneate and thinner at or near attachment of hilum, hilum punctiform, marginal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4. Seeds with papillae embedded in testa, areole walls thick, sometimes with jagged projections; capsules 6–13 mm long, subglobose, woody. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Subg. Kadua subgroup A 4. Seeds without papillae, areole walls usually thin; capsules 2.5–6 mm long, not woody, or in K. formosa 9–12 mm long, ellipsoid-cylindrical. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Subg. Kadua subgroup B. Rationalization of Seed Groups with Sections. Section Gouldia and Section Phyllozygia, which include K. fosbergii, K. axillaris (H. hillebrandii), K. affinis (H. terminalis), and K. tryblium, differ in Table 4 from subg. Kadua and sect. Wiegmannia in corolla bud characters: apices not depressed with lobes not inflexed, and limbs quadrangular. As described previously, the seeds and fruits differ strongly from all other taxa. Motley (2003) stated that there were two clades based on the dry versus fleshy fruits, and has further commented (pers. comm. January 2005) that he continues to consider these as separate clades based on his molecular sequence data. Although vegetatively similar to the rest of Kadua (Wagner et al. 1989, 1999) in seed structure, the traditional taxonomy based on corolla and fruit and molecular studies by Motley all agree that Gouldia is a distinctive subgroup, a subgroup here recognized as subgenus Gouldia. Section Gouldiopsis traditionally includes Kadua centranthoides, K. foggiana, and K. knudsenii. Fosberg’s (1943) key to sections stated that sect. Gouldiopsis has strongly quadrangular corolla bud limbs and capsules not much longer than wide. Of these, the capsule character seems unreliable, as other sections have capsules not much longer than wide. Fosberg stated that the three species differ from each other by characters of the thyrsoid inflorescence, leaf texture, and corolla lobe appendages. The most important of these characters are the corolla lobe appendages which occur in the Hawaiian and certain Pacific species. Wagner et al. (1999) described K. knudsenii as having a long appendage and K. centranthoides with an inconspicuous appendage. Examination of recent collections reveals that K, foggiana has minute appendages. Fosberg (1943) commented that section Gouldiopsis seems to have given rise to the genus Gouldia through K. knudsenii, which ‘‘shows a strong resemblance to G. terminalis var. elongata’’ (Kadua affinis). This latter concept is rejected here as contrary to seed evidence and molecular evidence from Motley (pers. comm.). Our study of K. foggiana and K. knudsenii found them to have seeds generally similar to species in subg. Kadua subgroup B, a form considered here as plesiomorphic for the subgenus Kadua. They differ strongly in seed characters from K. centranthoides which is a highly derived form within the section needing further study. An atypical element within section Gouldiopsis is the previously recognized section Bikkiocarpa for Kadua formosa, which is distinctive in its elongated capsules and in having corolla buds that are rounded, not strongly quadrangular. This species has the seed type described above in subg. Kadua subgroup B. Motley et al. (1998) suggested placement of K. formosa in sect. Gouldiopsis based on molecular evidence. Of the four seed types in the Hawaiian Hedyotideae, one with a centric hilum is characteristic of the subgenus Gouldia (the Gouldia type). The three types with the hilum marginal are characteristic of the subgenus Kadua. Of the latter three, variants of the cuneate Kadua seed type are plesiomorphic for the subgenus Kadua. 2005] 831 TERRELL ET AL.: HAWAIIAN HEDYOTIDINAE ACKNOWLEDGEMENTS. We thank Susann Braden for preparing the SEM micrographs and Marjorie Knowles for formatting and sizing the figures. We express our gratitude to two anonymous reviewers who made important suggestions. We thank Timothy Motley for providing helpful data from his molecular research. Ruth Schallert, botanical librarian, facilitated our hunts for hardto-find Pacific literature. TERRELL, E. E. 1996. Revision of Houstonia (Rubiaceae-Hedyotideae). Systematic Botany Monographs 48: 1–118. ——— and W. H. LEWIS. 1990. Oldenlandiopsis (Rubiaceae), a new genus from the Caribbean Basin, based on Oldenlandia callitrichoides Grisebach. Brittonia 42: 185–190. ——— and H. ROBINSON. 2003. Survey of Asian and Pacific species of Hedyotis and Exallage (Rubiaceae) with nomenclatural notes on Hedyotis types. Taxon 52: 775–782. ——— and R. P. WUNDERLIN. 2002. Seed and fruit characters in selected Spermacoceae and comparison with Hedyotideae (Rubiaceae). Sida 20: 549–557. ——— W. H. LEWIS, H. ROBINSON, and J. W. NOWICKE. 1986. Phylogenetic implications of diverse seed types, chromosome numbers, and pollen morphology in Houstonia (Rubiaceae). American Journal of Botany 73: 103–115. WAGNER, W. L. and D. H. LORENCE. 1998. A new dioecious species of Hedyotis (Rubiaceae) from Kaua’i, Hawaiian Islands, and the taxonomy of Kaua’i Hedyotis schlechtendahliana resolved. Novon 8: 311–317. ———, D. R. HERBST, and S. H. SOHMER. 1989. Contributions to the flora of Hawaii. II. Begoniaceae-Violaceae and the Monocotyledons. Bernice P. Bishop Museum Occasional Papers 29: 88– 130. ———,———, and———. 1990. Manual of the flowering plants of Hawai’i. 2 vols. Vol. 1, Rubiaceae. Honolulu: University of Hawaii Press, Bishop Museum Press. ———,———, and———. 1999. Manual of the flowering plants of Hawai’i. Rev. Ed. 2. vols. Vol. 1, Rubiaceae. Honolulu: University of Hawaii Press, Bishop Museum Press. LITERATURE CITED APPENDIX 1 The remaining two types occur in derived typical elements of the sections Gouldiopsis and Wiegmannia, the Gouldiopsis seed type in a single species, K. centranthoides, and the Wiegmannia seed type in sect. Wiegmannia. In this way, seed structure correlates with the basic evolutionary pattern of the native Hawaiian Hedyotideae based on corollas and fruit characters and reinforced by the molecular study. The most basic phyletic division in the group is completely characterized by one seed type. The remaining two more derived seed types are represented in the Hawaiian Hedyotideae as end products even as transitional forms remain in existence. It is fortuitous for reference purposes that the Gouldiopsis seed type and the Wiegmannia seed type are found in the type species of their respective sections. ANDERSSON, L., J. H. E. ROVA, and F. ALZATE GUARIN. 2002. Relationships, circumscription, and biogeography of Arcytophyllum (Rubiaceae) based on evidence from cpDNA. Brittonia 54: 40–49. BREMER, B. 1996. Phylogenetic studies within Rubiaceae and relationships to other families based on molecular data. Opera Botanica a Societate Botanica Lundensi 7: 33–50. ——— and J.-F. MANEN. 2000. Phylogeny and classification of the subfamily Rubioideae (Rubiaceae). Plant Systematics and Evolution 225: 43–72. CANDOLLE, A. P. DE. 1830. Rubiaceae. Pp. 341–622 in Prodromus systematis naturalis regni vegetabilis 4, ed. A. P. de Candolle. Paris: Treutel et Würtz. FOSBERG, F. R. 1937. The genus Gouldia (Rubiaceae). Bernice P. Bishop Museum Bulletin 147. 82 pp. ———. 1943. The Polynesian species of Hedyotis (Rubiaceae). Bernice P. Bishop Museum Bulletin 174. 102 pp. GREUTER, W., J. MCNEILL, F. R. BARRIE, H. M. BURDET, V. DEMOULIN, T. S. FILGUEIRAS, D. H. NICOLSON, P. C. SILVA, J. E. SKOG, P. TREHANE, N. J. TURLAND, and D. L. HAWKSWORTH (eds.). 2000. International code of botanical nomenclature (St. Louis code). Königstein: Koeltz Scientific Books. Regnum Vegetabile 138: 1– 474. MOTLEY, T. J. 2003. Phylogeny of Hawaiian and Pacific Hedyotis (Rubiaceae): fruit evolution and the implications for conservation and genomics. Abstracts of Annual Meeting, Mobile, Alabama, Botany 2003: 88–89. http://www.2003.botanyconference.org/ engine/search/detail.php?aid 5 377 ———, L. STRUWE, and V. A. ALBERT. 1998. Molecular systematics of Hawaiian Hedyotis (Rubiaceae). American Journal of Botany 85(6, Suppl.): 146. SKOTTSBERG, C. 1955. Chromosome numbers in Hawaiian flowering plants. Arkiv för Botanik utgivet av k. Svenska Vetenskapsakadamien 3: 63–70. STONE, B. C. and I. LANE. 1958. A new Hedyotis from Kauai, Hawaiian Islands. Pacific Science 12: 139–145. List of Kadua names. This appendix provides a nomenclator for the genus Kadua, which was treated as a distinct genus until Fosberg’s revision of the group (1943) where he included it within a broadly delimited Hedyotis, except for the fleshy-fruited species, which he treated in another segregate, Gouldia. Species of this group have been differentiated from the other species included within Hedyotis by their salverform, fleshy corollas with appendaged lobes, and either tardy and often incomplete septicidal dehiscence of the capsules or having indehiscent drupaceous capsules. Motley’s molecular sequence studies (Motley et al. 1998; Motley 2003) have shown this group to be monophyletic and distinct from Hedyotis. All of the necessary new combinations are made here by Wagner and Lorence for Kadua including species of sects. Austrogouldia and Oceanica not studied in this paper. Species already with valid names in Kadua are also listed for completeness and convenience. Brief distributional comments are given for the species of each section. KADUA Cham. & Schltdl., Linnaea 4: 157. Apr 1829. Hedyotis subg. Kadua (Cham. & Schltdl.) Fosberg, Bernice P. Bishop Mus. Bull. 174: 69. 1943.—LECTOTYPE: Kadua acuminata Cham. & Schltdl.; designated by K. M. Schumann in Engler & Prantl, Nat. Pflanzenfam. 4(4): 24. Jul 1891. The genus Kadua currently comprises 28 species all indigenous to Pacific islands with the majority (21) species in a diverse clade in the Hawaiian Islands, three species endemic to the Marquesas Islands, two species endemic to the Society Islands, one endemic to Rapa, and one fairly widespread Polynesian species, K. romanzoffiensis, from Tuamotu Archipelago, Austral Islands, Cook Islands, Ellice Islands, Gambier Islands, Line Islands, Pitcairn Islands, Society Islands, and Tokelau. Kadua subg. Gouldia (A. Gray) W. L. Wagner & Lorence, comb. nov. Gouldia A. Gray, Proc. Amer. Acad. Arts 4: 310. Sep 1859. Hedyotis sect. Gouldia (A.Gray) W.L.Wagner & Herbst in W.L.Wagner, Herbst & Sohmer, Bishop Mus. Occas. Pap. 29: 832 SYSTEMATIC BOTANY 111. 1989.—LECTOTYPE: Gouldia sandwicensis A. Gray, nom. illeg. (5 Kadua affinis DC.); designated by W. L. Wagner & Herbst in Wagner, Herbst & Sohmer, Bishop Mus. Occas. Pap. 29: 111. 1989 A Hawaiian subgenus of two sections and four species. Kadua sect. Gouldia (A. Gray) W. L. Wagner & Lorence, comb. nov. Gouldia A. Gray, Proc. Amer. Acad. Arts 4: 310. Sep 1859. 1. KADUA AFFINIS DC., Prodr. 4: 431. 1830. Petesia? terminalis Hook. & Arn., Bot. Beechey Voy. 85. 1832. Hedyotis terminalis (Hook. & Arn.) W. L. Wagner & D. R. Herbst, in Wagner, Herbst & Sohmer, Bishop Mus. Occas. Pap. 29: 112. 1989. 2. Kadua fosbergii (W. L. Wagner & D. R. Herbst) W. L. Wagner & Lorence, comb. nov. Hedyotis fosbergii W. L. Wagner & D. R. Herbst, in Wagner, Herbst & Sohmer, Bishop Mus. Occas. Pap. 29: 111. 1989. Gouldia st.-johnii Fosberg, Bernice P. Bishop Mus. Bull. 147: 62. 1937. 3. Kadua axillaris (Wawra) W. L. Wagner & Lorence, comb. nov. Gouldia axillaris Wawra, Flora 57: 297. 1874. Gouldia hillebrandii Fosberg, Bernice P. Bishop Mus. Bull. 147: 59. 1937. Hedyotis hillebrandii (Fosberg) W. L. Wagner & D. R. Herbst, in Wagner, Herbst & Sohmer, Bishop Mus. Occas. Pap. 29: 112. 1989. Kadua sect. Phyllozygia (W. L. Wagner & Herbst) W. L. Wagner & Lorence, comb. nov. Hedyotis sect. Phyllozygia W. L. Wagner & Herbst, Bishop Mus. Occas. Pap. 29: 113. 1989.—TYPE: Hedyotis tryblium D. R. Herbst & W. L.Wagner (5 Kadua tryblium (D. R. Herbst & W. L. Wagner) W. L. Wagner & Lorence). A Hawaiian section of a single species closely related to sect. Gouldia. 4. Kadua tryblium (D. R. Herbst & W. L. Wagner) W. L. Wagner & Lorence, comb. nov. Hedyotis tryblium D. R. Herbst & W. L.Wagner, in Wagner, Herbst & Sohmer, Bishop Mus. Occas. Pap. 29: 113. 1989. KADUA subg. KADUA Kadua subg. Kadua is subdivided into the remaining six sections of the genus. Kadua sect. Oceanica (Fosberg) W. L. Wagner & Lorence, comb. et stat. nov. Hedyotis subg. Oceanica Fosberg, Bernice P. Bishop Mus. Bull. 174: 67. 1943.—TYPE: Hedyotis romanzoffiensis (Cham. & Schldtl.) Fosberg (5 Kadua romanzoffiensis Cham. & Schltdl.). A unispecific section widespread on many of the low islands of southeastern Polynesia. 5. KADUA ROMANZOFFIENSIS Cham. & Schltdl., Linnaea 4:162. 1829. Hedyotis romanzoffiensis (Cham. & Schltdl.) Fosberg, Occas. Pap. Bernice P. Bishop Mus. 13 (19): 248. 1937. Kadua sect. Austrogouldia (Fosberg) W. L. Wagner & Lorence, comb. nov. Hedyotis sect. Austrogouldia Fosberg, Bernice P. Bishop Mus. Bull. 174: 28. 1943.—TYPE: Hedyotis raiateensis (J. W. Moore) Fosberg (5 Kadua raiateensis J. W. Moore). A section of six species of which one species is endemic to Rapa, two endemic in the Society Islands, and three endemic in the Marquesas Islands. 6. Kadua lucei (Lorence & J. Florence) W. L. Wagner & Lorence, comb. nov. Hedyotis lucei Lorence & J. Florence, Adansonia 22: 225. 2000. 7. Kadua nukuhivensis (J. Florence & Lorence) W. L. Wagner & Lorence, comb. nov. Hedyotis nukuhivensis J. Florence & Lorence, Adansonia 22: 224. 2000. [Volume 30 8. Kadua tahuatensis (Lorence & J. Florence) W. L. Wagner & Lorence, comb. nov. Hedyotis tahuatensis Lorence & J. Florence, Adansonia 22: 227. 2000. 9. KADUA RAPENSIS F. Br., Bernice P. Bishop Mus. Bull. 130: 283. 1935. Hedyotis rapensis (F. Br.) Fosberg, Occas. Pap. Bernice P. Bishop Mus. 13 (19): 250. 1937. 10. KADUA RAIATEENSIS J. W. Moore, Bernice P. Bishop Mus. Bull. 102: 43. 1933. Hedyotis raiateensis (J. W. Moore) Fosberg, Bernice P. Bishop Mus. Bull. 174: 28. 1943. 11. Kadua grantii (Fosberg) W. L. Wagner & Lorence, comb. nov. Hedyotis grantii Fosberg, Bernice P. Bishop Mus. Bull. 174: 29. 1943. Kadua sect. Protokadua (Fosberg) W. L. Wagner & Lorence, comb. nov. Hedyotis sect. Protokadua Fosberg, Bernice P. Bishop Mus. Bull. 174: 23. 1943.—TYPE: Hedyotis coriacea J.E.Smith (5 Kadua coriacea (J. E. Smith) W. L. Wagner & Lorence). A unispecific Hawaiian section. 12. Kadua coriacea (J. E. Smith) W. L. Wagner & Lorence, comb. nov. Hedyotis coriacea J. E. Smith, in Rees, Cycl. 1734. 1811. Kadua sect. Gouldiopsis (Fosberg) W. L. Wagner & Lorence, comb. nov. Hedyotis sect. Gouldiopsis Fosberg, Bernice P. Bishop Mus. Bull. 174: 56. 1943.—TYPE: Hedyotis centranthoides (Hook. & Arn.) Steud. (5 Kadua centranthoides Hook. & Arn.). Hedyotis sect. Bikkiocarpa Fosberg, Bernice P. Bishop Mus. Bull. 174: 25. 1943, syn. nov.—TYPE: Hedyotis formosa (Hillebr.) Fosberg (based on Kadua formosa Hillebr.). A Hawaiian section here treated as consisting of four species. The single species formerly treated in Hedyotis sect. Bikkiocarpa was shown by molecular evidence to be nested within sect. Gouldiopsis by Motley et al. (1998), and differs morphologically only in its elongate capsules. The group has been shown to be monophyletic (Motley et al. 1998, pers. comm.) by molecular sequence data and by the buds apex not depressed as in other members of the genus, but has both intermediate and derived seed characteristics. 13. KADUA CENTRANTHOIDES Hook. & Arn., Bot. Beechey Voy. 85. 1832. Hedyotis centranthoides (Hook. & Arn.) Steud., Nomencl. bot., ed. 2, 1: 727. 1840. 14. Kadua foggiana (Fosberg) W. L. Wagner & Lorence, comb. nov. Hedyotis foggiana Fosberg, Bernice P. Bishop Mus. Bull. 174: 65. 1943. 15. KADUA KNUDSENII Hillebr., Fl. Hawaiian Isl. 162. 1888. Hedyotis knudsenii (Hillebr.) Fosberg, Bernice P. Bishop Mus. Bull. 174: 57. 1943. 16. KADUA FORMOSA Hillebr., Fl. Hawaiian Isl. 165. 1888. Hedyotis formosa (Hillebr.) Fosberg, Bernice P. Bishop Mus. Bull. 174: 26. 1943. Kadua sect. Kadua A Hawaiian section of two very closely related and variable species. 17. KADUA ACUMINATA Cham. & Schltdl., Linnaea 4: 163. 1829. Hedyotis acuminata (Cham. & Schltdl.) Steud., Nomencl. bot., ed. 2, 1: 726. 1840. 18. KADUA FLUVIATILIS C. N. Forbes, Occas. Pap. Bernice P. Bishop Mus. 5(1): 6. 1912. Hedyotis fluviatilis (C. N. Forbes) Fosberg, Bernice P. Bishop Mus. Bull. 174: 90. 1943. Kadua sect. Wiegmannia (Meyen) W. L. Wagner & Lorence, comb et stat. nov. Wiegmannia Meyen, Reise 2: 139. 18–23 Aug 1834 (‘1835’). Hedyotis sect. Wiegmannia (Meyen) Fosberg, Bernice P. Bishop Mus. Bull.174: 29. 1943.—TYPE: Wiegmannia glauca Meyen (5Kadua cordata Cham & Schltdl.) A complex section of 10 closely related Hawaiian species. 2005] TERRELL ET AL.: HAWAIIAN HEDYOTIDINAE 19. KADUA COOKIANA Cham. & Schltdl., Linnaea 4: 158. 1829. Hedyotis cookiana (Cham. & Schltdl.) Steud., Nomencl. bot., ed. 2, 1: 727. 1840. 20. KADUA CORDATA Cham & Schltdl., Linnaea 4: 160. 1829. 20a. KADUA CORDATA Cham & Schltdl. subsp. CORDATA Hedyotis schlechtendahliana Steud., Nomencl. bot., ed. 2, 1: 728. 1840. 20b. Kadua cordata Cham & Schltdl. subsp. remyi (Hillebr.) W. L. Wagner & Lorence, comb. nov. Kadua remyi Hillebr., Fl. Hawaiian Isl. 162. 1888. Hedyotis schlechtendahliana Steud. subsp. remyi (Hillebr.) Fosberg, Bernice P. Bishop Mus. Bull. 174: 40. 1943. 20c. Kadua cordata Cham & Schltdl. subsp. waimeae (Wawra) W. L. Wagner & Lorence, comb. nov. Kadua waimeae Wawra, Flora 57: 264. 1874. Hedyotis schlechtendahliana Steud. subsp. waimeae (Wawra) W. L. Wagner & Lorence, Novon 8: 316. 1998. 21. Kadua degeneri (Fosberg) W. L. Wagner & Lorence, comb. nov. Hedyotis degeneri Fosberg, Bernice P. Bishop Mus. Bull. 174: 55. 1943. 21a. KADUA DEGENERI (Fosberg) W. L. Wagner & Lorence subsp. DEGENERI 21b. Kadua degeneri (Fosberg) W. L. Wagner & Lorence subsp. coprosmifolia (Fosberg) W. L. Wagner & Lorence, comb. nov. 833 Hedyotis degeneri Fosberg var. coprosmifolia Fosberg, Bernice P. Bishop Mus. Bull. 174: 56. 1943. 22. Kadua elatior (H. Mann) W. L. Wagner & Lorence, comb nov. Kadua cookiana Cham. & Schltdl. var. elatior H. Mann, Proc. Amer. Acad. Arts 7: 172. 1867. Hedyotis elatior (H. Mann) Fosberg, Brittonia 8: 167. 1956. 23. Kadua flynnii (W. L. Wagner & Lorence) W. L. Wagner & Lorence, comb. nov. Hedyotis flynnii W. L. Wagner & Lorence, Novon: 8: 311. 1998. 24. KADUA FOLIOSA Hillebr., Fl. Hawaiian Isl. 164. 1888. Hedyotis foliosa (Hillebr.) Fosberg, Bernice P. Bishop Mus. Bull. 174: 44. 1943. 25. KADUA LAXIFLORA H. Mann, Proc. Amer. Acad. Arts 7: 171. 1867. Hedyotis mannii Fosberg, Bernice P. Bishop Mus. Bull. 174: 49. 1943. 26. KADUA LITTORALIS Hillebr., Fl. Hawaiian Isl. 166. 1888. Hedyotis littoralis (Hillebr.) Fosberg, Bernice P. Bishop Mus. Bull. 174: 53. 1943. 27. KADUA PARVULA A. Gray, Proc. Amer. Acad. Arts 4: 317. [Sept]1859. Hedyotis parvula (A. Gray) Fosberg, Bernice P. Bishop Mus. Bull. 174: 54. 1943. 28. Kadua st.-johnii (B. C. Stone & Lane) W. L. Wagner & Lorence, comb. nov. Hedyotis st.-johnii B. C. Stone & Lane, Pacific Science 12: 141. 1958.