KEW BULLETIN VOL. 63: 669–673 (2008) Phuphanochloa, a new bamboo genus (Poaceae: Bambusoideae) from Thailand Sarawood Sungkaew1,2, Atchara Teerawatananon1,3, John A. N. Parnell1, Chris M. A. Stapleton4 & Trevor R. Hodkinson1 Summary. A new monotypic bamboo genus Phuphanochloa (Poaceae: Bambusoideae) from north-eastern Thailand is described, together with a new species, P. speciosa. Key Words. Bambuseae, Bambusoideae, Phuphanochloa, Poaceae, Thailand. Introduction During field work for the revision of the genus Dendrocalamus for the Flora of Thailand, vegetative and flowering specimens of a distinctive new bamboo were found. This bamboo was included in a comprehensive DNA sequence analysis (Sungkaew et al. in press), and can now be described as a new genus Phuphanochloa, on the basis of morphology and molecular phylogenetics. Phuphanochloa Phuphanochloa Sungkaew & Teerawat., gen. nov. Poacearum-Bambusoidearum rhizomatibus sympodialibus brevicollibus. Culmus unicaespitosus erectus. Inflorescentia indeterminata; spicula 1 – 4 gluma, 7 – 9 flores et 1 – 2 flores terminales vestigiales ferenti, internodio basalis rachillae longo, 3 lodiculis, staminibus filamentis liberis 6, ovario apice pubescenti, stylo solitarium, stigmatibus 3. Typus: P. speciosa Sungkaew & Teerawat. Rhizomes short-necked pachymorph. Culms unicaespitose, straight and erect; internodes smooth; nodes slightly swollen. Branch bud solitary at each node, developing into several branches, the primary one dominant. Culm sheaths deciduous, occasionally tardily deciduous at basal nodes, coriaceous; blades spreading to deflexed; auricles absent, or inconspicuous rims, margins entire, occasionally slightly wavy, glabrous; ligule short, margin toothed to bristly. Leafy branchlets bearing 6 – 8 moderate sized leaves. Leaves hairy underneath, pseudo-petioles short; sheaths hairy; auricles absent or of tiny rims bearing oral setae; ligule short, margin toothed. Inflorescences indeterminate, bracteate, borne on leafless branches; pseudospikelets clustered in spicate mass, 0 – few small empty bracts, 2 – 4 bracts subtending prophyllate buds; internodes glabrous. Spikelets large, ovate to elliptic in outline, purple, laterally compressed; glumes 1 – 4, shorter than the lowest lemma, coriaceous or somewhat rigid; fertile florets 7 – 9, with 1 – 2 terminal vestigial florets, shorter than fertile florets; rachilla internodes between florets (from the second floret upwards) short, disarticulating below each floret, rachilla internode distal to the lowermost floret frequently longer; lemmas chartaceous, the basal ones distally more rigid; paleas 2-keeled; lodicules usually 3; stamens 6, filaments free; ovary hairy at the top, style more or less hairy and flattened upwards, stigma 3, slightly plumose. Caryopsis hirsute at apex, beaked with the persistent base of the style. Phuphanochloa can be included in subtribe Bambusinae in the classification of Soderstrom & Ellis (1987). It shares several characters in common with Bambusa, Accepted for publication October 2008. 1 Department of Botany, School of Natural Sciences, Trinity College Dublin, University of Dublin, Dublin 2, Ireland. 2 Department of Forest Biology, Faculty of Forestry, Kasetsart University, Bangkok, Thailand. 3 Thailand Natural History Museum, National Science Museum, Techno polis, Pathum Thani, Thailand. 4 Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK. © The Board of Trustees of the Royal Botanic Gardens, Kew, 2008 KEW BULLETIN VOL. 63(4) 670 including similar vegetative appearance and branching, indeterminate spicate inflorescences with six stamens and free filaments. There are also few glumes, many (7 – 9) fertile florets which have variably elongated rachilla internodes that disarticulate below each floret. However, in Phuphanochloa the spikelets usually break up at maturity in one of two ways (both of which are usually present on any single individual); either the spikelet totally breaks up above the glume(s) leaving only the elongated rachilla internode (0.5 – 2 cm long), or it breaks up above the glume(s) and above the lowest floret leaving the upper part of the elongated rachilla internode (to 0.5 cm long) along with the glume(s) and intact lowest floret (this is not the case in Bambusa). In the length of the basal rachilla internodes, the genus shows similarities to Bonia Balansa from S China (Xia & Stapleton 2006), but the spikelets of Phuphanochloa are broader, and culm branching is not solitary. In addition, in Bambusa there are 1 – 3 distinctly plumose stigmas while in Phuphanochloa there are usually three, and they are only slightly plumose. Phuphanochloa can be easily distinguished from Dendrocalamus by its elongated and disarticulating rachilla internodes (very short and not disarticulating in Dendrocalamus) and the less globose inflorescences. Phuphanochloa differs from Gigantochloa, in having free filaments instead of fused filaments. The differences between these four genera and Phuphanochloa are summarised in Table 1. The results from combined analysis of five plastid DNA regions (trnL intron, trnL-F intergenic spacer, atpB-rbcL intergenic spacer, rps16 intron, and matK gene region, Fig. 1) (Sungkaew et al. in press) show that Phuphanochloa is sister to a group comprising Bambusa species (B. beecheyana Munro, B. emeiensis L. C. Chia & H. L. Fung (as Neosinocalamus affinis in the tree), B. malingensis McClure and B. oldhamii Munro) with parsimony bootstrap support of 86% and a Bayesian posterior probability (PP) value of 1.00. These four species of Bambusa group together with bootstrap support of 80% (1.00PP). They represent three of the four subgenera of Bambusa according to Xia et al. (2006). B. malingensis represents subg. Bambusa; B. beecheyana and B. oldhamii represent subg. Dendrocalamopsis; and B. emeiensis represents subg. Lingnania. The results of the molecular analysis Table 1. Comparative table of habit and morphological characters between Bambusa, Bonia, Dendrocalamus, Gigantochloa and Phuphanochloa. Characters Bambusa Bonia Dendrocalamus Gigantochloa Phuphanochloa Habit Branch number at mid-culm branch complement Culm-sheath auricles; oral setae/ Culmsheath blade usually erect several scrambling single usually erect several usually erect several usually erect several usually conspicuous; always present/ usually erect conspicuous, but often small to absent; present or absent/erect to deflexed usually absent or small; usually absent, occasionally present/erect to deflexed usually absent or small; always absent/spreading to deflexed, never erect Number of glumes per spikelet Number of fertile florets per spikelet Rachilla internodes 0–3 usually conspicuous, occasionally inconspicuous or small; usually present, occasionally absent/erect to deflexed 0–2 (1 –) 2 – 4 (– 9) 1–5 1–4 2 – 13 3–9 1–8 (1 –) 2 – 5 7–9 distinct and disarticulating typically (1 –) 3, plumose typically free distinct and disarticulating typically 3, plumose obscure and not disarticulating typically 1 (– 3), plumose typically free distinct and disarticulating typically 3, slightly plumose typically free either breaking up above the glume(s) or between the florets unknown obscure and not disarticulating typically 1, plumose always fused into a firm tube usually breaking up above the glume(s) Stigma Filaments Breaking up at maturity of spikelets typically free © The Board of Trustees of the Royal Botanic Gardens, Kew, 2008 usually breaking up above the glume(s) usually breaking up in one of two ways (both of which are usually present on any single individual); either above the glume(s) or above the lowest floret PHUPHANOCHLOA, A NEW BAMBOO GENUS 671 Fig. 1. Part of a multigene region phylogenetic tree (trnL intron, trnL-F intergenic spacer, atpB-rbcL intergenic spacer, rps16 intron, and matK gene region) of Bambusoideae (from Sungkaew et al. in press). Values above branches represent branch length, values below branches represent parsimony bootstrap support and bracketed numbers represent Bayesian posterior probability value (PP). Phuphanochloa is sister to a group of Bambusa species (B. beecheyana Munro, Neosinocalamus affinis (Rendle) P. C. Keng (=B. emeiensis L. C. Chia & H. L. Fung), B. malingensis McClure and B. oldhamii Munro) and does not group closely with another two Bambusa species (B. bambos (L.) Voss and B. tulda Roxb.). show that Phuphanochloa cannot be included in any of these three subgenera. Phuphanochloa cannot be considered as a member of the fourth subgenus of Bambusa (subg. Leleba) either. This is because subg. Leleba typically has a broad culm-sheath blade (base of culm-sheath blade ½ – ¾ width of sheath apex) as remarked by Xia et al. (2006); it is much smaller than ½ in Phuphanochloa. Its culm-sheath blade, in contrast, is more similar to those of Dendrocalamus or Gigantochloa. In addition, subg. Leleba has a thick papery culm sheath with a deciduous culm-sheath blade (Xia et al. 2006) while Phuphanochloa has a coriaceous culm sheath with a persistent culm-sheath blade. Phuphanochloa is therefore distinct from Bambusa. The genus is named after Phu Phan National Park, in Sakon Nakhon Province, north-eastern Thailand, where the species Phuphanochloa speciosa grows. Phuphanochloa speciosa Sungkaew & Teerawat., sp. nov. Culmi unicaespitosi, compacti, c. 5 – 10 m longi et 3 – 5 cm diametri, internodia 25 – 30 cm longa; vaginis culmi pubescens; laminis foliorum pubescens infra; specula purpura, 1 – 4 gluma, 7 – 9 flores et 1 – 2 flores terminales vestigiales ferenti, lemmata hirsuta dorsi prope basin; styli plus minusve pubescens, stigmatum 3 parum plumosus. Typus: Thailand, Sungkaew & Teerawatananon 472 (holotypus TCD!; isotypi BKF!, K!, Herbarium of Faculty of Forestry, Kasetsart University!, Herbarium of Thailand Natural History Museum, National Science Museum!). Rhizomes short-necked pachymorph. Culms self-supporting, unicaespitose in a dense clump, straight and erect, about 5 – 10 m long, 3 – 5 cm in diam., walls 0.5 – 1 cm thick, smaller culms sometimes solid at basal internodes, culm tips more or less arched outwards; internodes 25 – 30 cm long; young culms glabrous, white-waxy, mature culms, green; nodes slightly swollen, all nodes without verticils of roots. Branches developing at all nodes to near base, several branches at each node, the primary one dominant, without aerial roots. Culm sheaths deciduous, occasionally tardily deciduous at basal nodes, coriaceous, 20 – 25 cm long by 12 – 17 cm wide, top obtuse, scattered with short pale hairs on the back, sometimes with a slight distal abaxial wrinkle; blades lanceolate, spreading to deflexed, 2 – 3.5 cm long, about 0.5 – 1 cm wide near the base, hairy at the adaxial base; auricles absent, or small rims, about 1 mm high, margins usually entire, occasionally slightly wavy, glabrous; ligule 2 – 3 mm high, margin toothed to bristly, bristles 2 – 5 mm long. Leaves 6 – 8 per branchlet; leafblades 10 – 15 cm long by 1 – 1.3 cm wide, abaxially hairy, apex acuminate, base acute, pseudo-petioles 0.5 – 2 mm long, secondary veins in 3 – 4 pairs, intermediate veins 5 – 6; auricles absent or of tiny rims bearing oral setae 1 – 3 mm long; ligule 1 – 2 mm high, apex obtuse, margin toothed; sheaths 4 – 5 cm long, hairy. Inflorescences indeterminate, bracteate, borne on leafless branches; pseudospikelets clustered in spicate mass, 2 – 4 cm in diam., 0 – few small empty bracts, 2 – 4 bracts subtending prophyllate buds; internodes 2 – 7 cm long, glabrous. Spikelets ovate to elliptic (from the second floret upwards), 1 – 2 cm long by 0.5 – 1 cm wide, purple, laterally compressed; glumes 1 – 4, shorter than the lowest lemma, coriaceous or somewhat rigid, 11 – 17-nerved; fertile florets 7 – 9, with 1 – 2 terminal vestigial florets, shorter than fertile florets; rachilla internodes be© The Board of Trustees of the Royal Botanic Gardens, Kew, 2008 672 KEW BULLETIN VOL. 63(4) Fig. 2. Phuphanochloa speciosa. A culm shoot; B culm sheath; C leafy branch; D flowering branch; E flowering branch, showing 2 mature pseudospikelets (the one on the left with floret parts fallen); F a pseudospikelet, showing (from the base) an empty bract, 3 bracts subtending prophyllated buds (gemmiferous bracts), 2 glumes, 9 florets with a hidden vestigial floret; G glumes; H lemmas, showing ventral view (left) and dorsal view (right); J paleas, intermediates are found; K terminal vestigial florets; L pistil; M stamens. A – C from Sungkaew & Teerawatananon 191; D – M from Sungkaew & Teerawatananon 472. DRAWN BY A. TEERAWATANANON. © The Board of Trustees of the Royal Botanic Gardens, Kew, 2008 PHUPHANOCHLOA, A NEW BAMBOO GENUS tween florets (from the second floret upwards) short, 1 – 1.5 mm long, disarticulating below each floret, rachilla internode distal to the lowermost floret frequently longer, to 0.5 cm; lemmas chartaceous, the basal ones distally more rigid, 6 – 11.5 mm long, with a tuft of brown hairs on the back near the base, 13 – 21-nerved, apex acute; paleas coriaceous, 5 – 10 mm long, 2-keeled on the back, slightly winged, wings 0.5 – 0.7 mm wide, keels and margins ciliate, the uppermost slightly winged, keeled but only sparsely or not ciliate, outside glabrous, inside scattered with short and minute hairs, apex acute or slightly cleft, 2 – 3-nerved between keels, 1 – 2-nerved between keel and margin; lodicules usually 3, hyaline, fringed with fine cilia, distally shortly pubescent; stamens 6, filaments free, anthers 3 – 4 mm long, yellow, tips shortly apiculate; ovary ovate-umbonate, summit hairy, style more or less hairy and flattened upwards, stigma 3, flat and thin, slightly plumose. Caryopsis oblong-elliptic, 5 – 6 mm long, apex hirsute, beaked with the persistent base of the style, furrowed on one side. Fig. 2. DISTRIBUTION. Endemic to north-eastern Thailand. THAILAND. NE21, Sakhon Nakhon: Phu Phan National Park, base of Nang Mern cliff, sterile, 14 Aug. 2004, Sungkaew & Teerawatananon 191 (TCD, Herbarium of Faculty of Forestry, Kasetsart University; Herbarium of Thailand Natural History Museum, National Science Museum), fertile, 11 April 2005, Sungkaew & Teerawatananon 472 (holotype TCD; isotypes BKF, K, Herbarium of Faculty of Forestry, Kasetsart University, Herbarium of Thailand Natural History Museum, National Science Museum), fertile, 20 March 2006, Sungkaew & Teerawatananon 884 (TCD, Herbarium of Faculty of Forestry, Kasetsart University, Herbarium of Thailand Natural History Museum, National Science Museum). HABITAT. Deciduous dipterocarp forest; c. 500 m. CONSERVATION STATUS. Uncertain but probably rare; known from only a single locality. NOTES. Spikelets break up at maturity in one of two ways (both of which are usually present on any single 673 individual); either the spikelet totally breaks up above the glume(s) leaving only the elongated rachilla internode (0.5 – 2 cm long), or it breaks up above the glume(s) and above the lowest floret leaving the upper part of the elongated rachilla internode (to 0.5 cm long) along with the glume(s) and intact lowest floret. Acknowledgements We are grateful to Drs Soejatmi Dransfield and Wong Khoon Meng for their valuable suggestions and constructive comments on this paper. We also thank the two anonymous reviewers for their comments on the manuscript and their suggestions for improvement. This work was supported by the TRF/BIOTEC Special Program for Biodiversity Research and Training grant T_147003, a Trinity College Dublin, Ireland Postgraduate Studentship, and the Trinity College Dublin Postgraduate Travel Reimbursement Fund. References Soderstrom, T. R. & Ellis, R. P. (1987). The position of bamboo genera and allies in a system of grass classification. In: T. R. Soderstrom, K. W. Hilu, C. S. Campbell & M. E. Barkworth (eds.), Grass systematics and evolution, pp. 225 – 238. Smithsonian Institution, Washington, D.C. Sungkaew, S., Stapleton, C. M. A., Salamin, N. & Hodkinson, T. R. (in press). Non-monophyly of the woody bamboos (Bambuseae, Poaceae): a multi-gene region phylogenetic analysis of Bambusoideae s.s. J. Pl. Res. Xia, N. H. & Stapleton, C. M. A. (2006). Bonia Balansa. In: Z-Y. Wu & P. H. Raven (eds.), Flora of China 22: 49 – 50. Science Press, Beijing & Missouri Botanical Garden, St. Louis. ____, Chia, L. C., Li, D. Z. & Stapleton, C. M. A. (2006). Bambusa Schreber. In: Z-Y. Wu & P. H. Raven (eds.), Flora of China 22: 9 – 38. Science Press, Beijing & Missouri Botanical Garden, St. Louis. © The Board of Trustees of the Royal Botanic Gardens, Kew, 2008