Mycol. Res. 100 ( 2 ) . 193-194 (1996) Printed in Great Britain 193 Delimitation of Boubovia and Pulvinula Y.-J. YAO',' A N D B. M. SPOONER' Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE, U.K. School of Biomolecular Sciences, Liuerpool John Moores University, Byrom Street, Liverpool L3 3AF, U.K. Pulvinula and Boubovia share the characters of apically curved or hooked paraphyses, a forked ascus base in most species, and often pulvinate apothecia. Pulvinula is delimited to include species having globose ascospores, with asci thin-walled throughout development, whilst Boubovia contains species having ellipsoid to subglobose ascospores, and the ascus wall thickened in the eady stages of development, especially at the time of ascospore delimitation. A new combination for the British species of Boubovia, B. nicholsonii, previously known as Humaria nicholsonii, is made, and a revision of the type is given. Two other combinations, B. ascoboloides and B. subprolata, are also proposed. Pulvinula oualispora is tentatively placed as a synonym of B. nicholsonii. A key to the known species of Boubovia is provided. Boubovia Svri-ek in Ceska Mykol. 31: 71 (1977). discomycetes having discoid to pulvinate apothecia, globose Apofhecia small, mostly less than 5 mm diam., scattered to ascospores, and apically curved or hooked paraphyses gregarious. Disc concave, flat to convex, yellow, orange(Boudier, 1885, 1907). The genus was investigated by Pfister yellow or greenish yellow, smooth. Receptacle shallow-cupulate (1976), who included 1 7 species, of which P. ovalispom Boud. to cupulate, sessile, margin entire, externally glabrous. Ecfal has ellipsoid spores. Two other species, P. ascoboloides Korf & and medullary excipulum of fexfura globulosa to angularis, or W . Y. Zhuang and P. subprolata Korf & W. Y. Zhuang, with fexfura infricafa. Asci cylindric, operculate, I-, thick-walled ellipsoid or subglobose ascospores, have also been described when young, especially at the time of ascospore delimitation, (Korf & Zhuang, 1984, 1991). base usually forked, uniseriately (4)8-spored. Ascospores When an investigation of Humaria Fuckel was conducted unicellular, colourless, ellipsoid to broadly ellipsoid! or for the project 'Ascomycetes of Great Britain and Ireland', the subglobose, guttulate at least when young, sometimes type of Humaria nicholsonii Massee was examined and found containing a de Bary bubble, smooth or finely ornamented or to belong in the genus Boubovia Svri-ek, which is here brought enclosed in an irregular cyanophilic sheath. Paraphyses filiform, to attention. Boubovia was proposed to accommodate a single slender, septate, branched or not, apically curved to contorted. species, Humaria lufeola Velen., which has ellipsoid ascospores, a forked ascus base, and apically curved to spirally curled Type species: Humaria lufeola Velen. (syn. Boubovia lufeola (Velen.) paraphyses (Svrrek, 1977, 1979). Humaria nicholsonii displays Svrtek). the same generic characters as this species and, in addition, its Habitat: on dead leaves, soil, animal dung, pebbles, etc. thick-walled young asci are reminiscent of the species with ellipsoid spores hitherto placed in Pulvinula. All these species Disfribufion: Europe, Asia, North and South America and Africa, have the combination of ellipsoid or subglobose ascospores possibly worldwide. and ascus wall thickened in the early stages of development, quite distinct from other species with globose spores and asci which remain thin-walled throughout development. In the Boubovia ascoboloides (Korf & W. Y. Zhuang) Y. J. Yao & Spooner, comb. nov. revision of the type species of Boubovia, B. lufeola, Svri-ek Pulvinula ascoboloides Korf & W . Y. Zhuang in Mycofaxon 20: (1979) described 'young asci with wall up to 1 bm thick'. It 610 (1984). appears clear that these species form a closely related group . and it would be appropriate to assign them to the genus This species was described from China as having a unique Boubovia. Combinations for these species in this genus are loosening, thick, irregular, cyanophilic sheath enveloping the proposed below, with a revision of the type of Humaria ascospore (Korf & Zhuang, 1984). nicholsonii and a discussion of Pulvinula ovalispora. A full description of the genus Boubovia and a key to known species Boubovia subprolata (Korf & W. Y. Zhuang) Y. J. Yao & are also provided. Spooner, comb. nov. Pulvinula Boud. was originally established for a group of Pulvinula and Boubouia 194 Key to species of Boubovia 1. Ascospores subglobose, (9.5-1 10.G12.5 (-13.5) x (PO-) 95-100 1. Ascospores ellipsoid, usually longer than 13.0 pm . . 2. Ascospores, 190-21.5 x 8.5-100 pm . . . . 2. Ascospores, 11.0-18.0 x 6 . W 0 pm . . . . 3. Ascospores enclosed by a cyanophilic sheath . . . 3. Ascospores lacking a cyanophilic sheath . . . . lm . . . . . . . . . . . . . . . . . . . . . . . . . . . Puluinula subprolafa Korf & W . Y. Zhuang in Mycotaxon 40: a later re-evaluation of P, ovalispora will not affect the use of the former name in Boubovia. The de Bary bubble in the ascospores is clearly evident in the specimen examined, and is well illustrated in B. subprolata by Korf & Zhuang (1991). Ascospores of Pulvinula ovalispora were also demonstrated to contain a de Bary bubble, which is said to be an irregular shape (Korf & Zhuang, 1984). From the illustration provided by Korf & Zhuang (1991), the de Bary bubble in spores of P. oualispora is rather similar to that seen in the holotype of B. nicholsonii. Guttulation was also reported in young spores of B. ascoboloides (Korf & Zhuang, 1984) and may possibly occur in fresh material of B. luteola (Velenovsky, 1934; Svrcek, 1979). It seems that the significance of spore guttulation and of de Bary bubbles in delimiting the genus requires further investigation. 100 (1991). This is a Macaronesian species described recently (Korf & Zhuang, 1991). It is characterized by broadly ellipsoid to subglobose ascospores. The very thick-walled asci when young indicate its affinities with species of Boubouia, having ellipsoid ascospores, rather than those of Pulvinula having globose ascospores. Boubovia nicholsonii (Massee) Spooner & Y. J. Yao, comb. nov. Humaria nicholsonii Massee in Naturalist, Hull 1901: I88 (1901). Apothecia 2.0-3.5 mm diam. when dried (as '4.0-70 mrn across' in the protologue), gregarious. Disc concave to flat, sometimes slightly convex, orange-yellow, smooth. Receptacle globose at first, gradually becoming plane, shallow-cupulate, sessile, margin entire, externally glabrous. Ecfal excipulum of globose to elongate or angular cells 70-15.0 x 7.0-10.0 ym. Medullary excipulum indistinct, of woven, narrow, septate hyphae. Asci cylindric, 95-125 x 8.0-10.5 pm ('65-70 x 8-9 y' in the protologue), operculate, I-, thick-walled when young, appearing 2-layered when mounted in ]actophenol cotton blue, base forked, uniseriately (4-) 8-spored. Ascospores unicellular, colourless, ellipsoid, 11.0-12.5 x 6.0-7.0 ym ('10 6 ~ m in ' the protologue), frequently containing a de Bary bubble, sometimes evidently 1-guttulate, smooth. Paraphyses filiform, slender, septate, simple, strongly curved and not enlarged at apex, 1.0-1.5 Vm diam. Specimen examined: England, Surrey, Royal Botanic Gardens, Kew, on dead leaves, March 1898, G. Nicholson (holotype, K). Pulvinub ovalispora is apparently closely related to this 'pecies and may prove conspecific; the of P. ovalis~orahas not been exmined by the present authors. Humaria nicholsonii is, in any case, an older species epithet, and (Accepted 24 June 1995) . . . . . . . . . . . . . . . . . . . . . . . . . . . . B. lufeola . . B. ascoboloides B. nicholsonii . . B. subprolafa . 2 3 We wish to thank Professor D. L. Hawksworth for reading of the manuscript. The project 'The Ascomycetes of Great Britain and Ireland' is funded by a grant (GR3/8284) from the Natural Environment Research CounciI. REFERENCES Boudier, E. (1885). Discomyciltes Charnus. Sociiti Mycologique, Bulletin 1, 91-120. Boudier, E. (1907). Histoire et Class$cation des Discomyc2tes &Europe. Librairie des Sciences Klincksieck: Korf, R. P. & Zhuang, w.-Y.(1984). The ellipsoid-spored species of Pulvinub (Pezizaies). Mycotaxon 20, 607-616. Kerf. R. p. & Zhuang, W.-Y. (1991). A preliminary Discom~ceteflora of Macaronesia: Part 16. Otideaceae, Scutellinioideae.Mycotaxon 40, 79-106. Pfister, D. H. (1976). A synopsis of the genus Pulvinula. Occasionai Papers of the Herbarium 'f CryptogamicBotany '-I9. SvrSek, M. (1977). New combinations and new taxa in operculate Discomycetes (Pezizales). deska' Mykologie 31, 69-71. SvrPek, M. (1976, published in 1979). A taxonomic revision of Velenovsky's types of operculate Discomycetes (Pezizales) preserved in National Museum, Prague, Acta Musei Nafiona/is Prague 32 (2-4). 115-194, Velenovsk?, J. (1934). Monographia Discomycetum Bohemtae. Velenovsk$: Pragae, Czechoslovakia. 2 '