Gardens’ Bulletin Singapore 69(1): 75-80. 2017 75 doi: 10.3850/S2010098116000058 A noteworthy Dendrocalamus (Poaceae: Bambusoideae) from Sumatra, Indonesia I Putu Gede P. Damayanto1 & E.A. Widjaja2 herbarium Bogoriense, Research Center for Biology, Indonesian Institute of Sciences, Jl. Raya Jakarta-Bogor Km. 46, Cibinong 16911, Indonesia 2Present address RT/RW 03/01, Kp. Cimoboran, Ds. Sukawening, Dramaga Sub District, Bogor District, Indonesia parlida.damayanto.tab @ gmail.com ABSTRACT. There are eight species of Dendrocalamus Nees (Dendrocalamus asper (Schult.) Backer, D. bengkalisensis Widjaja, D. brandisii (Munro) Kurz, D. buar Widjaja, D. giganteus Munro, D. bait Widjaja, D. latiflorus Munro, D. membranaceus Munro), wild or cultivated, already recorded for Sumatra. A new species is added to this list, Dendrocalamus luteus Damayanto & Widjaja, which grows wild in the Indonesia Ecosystem Restoration area in Sumatra’s Jambi and South Sumatra Provinces. The new species is described, illustrated, and included in an identification key to all Sumatran Dendrocalamus species. Keywords. Bambusoideae, Dendrocalamus luteus, new species, Sumatra Introduction According to Widjaja et al. (2014) Sumatra has the highest bamboo diversity in Indonesia, with at least 80 species, of which 32 species are endemic to the island. Three of these Sumatran endemic species are in the genus Dendrocalamus Nees (Dendrocalamus bengkalisensis Widjaja, D. buar Widjaja, D. bait Widjaja), another species of Dendrocalamus is newly described here, and five other species (D. asper (Schult.) Backer, D. brandisii (Munro) Kurz, D. giganteus Munro, D. latiflorus Munro, D. membranaceus Munro) are found only in cultivation. An identification key to these nine Dendrocalamus spp. in Sumatra is presented. Identification Key to Dendrocalamus species in Sumatra la Dominant primary branch axes at middle to distal parts of culm growing long and overarching onto neighbouring trees.2 lb. Dominant primary branch axes not especially elongated, never overarching onto neighbouring trees.5 2a. Leaf blade pubescent on lower surface.3 2b. Leaf blade glabrous on lower surface.4 76 Card. Bull. Singapore 69(1) 2017 3a Culm sheath apex with white wax and white to brown hairs at the base, culm sheath margin with white to brownish hairs; culm below nodes covered with brownish and whitish hairs and white waxiness; leaf midrib prominent and leaf base yellow.D. luteus 3b Culm sheath completely covered by white hairs and without wax, culm sheath margin glabrous; culm below nodes glabrous; leaf midrib not prominent and leaf base not yellow.D. bengkalisensis 4a Culm sheath auricles rim-like and crisped to blade base; ligules with 4-15 mm long bristles.D. buar 4b. Culm sheath auricles rounded lobes; ligules glabrous.D. bait 5a. Culm sheath auricles rim-like.D. latiflorus 5b. Culm sheath auricles small or rounded lobes, with wavy folds or crisped to blade base.6 6a. Lower culm of young culm with dense velvety brown hairs.D. asper 6b. Lower culm of young culm without velvety hairs.7 7a Culm sheath auricles crisped to the blade base; culm sheath ligules more than 1 mm high.D. giganteus 7b Culm sheath auricles small lobes with wavy folds; culm sheath ligules up to 0.5 mm high.8 8a Culm sheath auricle glabrous; blade usually shorter than half of the sheath length .D. brandisii 8b Culm sheath auricle with long bristles; blade usually exceeding half of the sheath length.D. membranaceus Dendrocalamus luteus Damayanto & Widjaja, sp. nov. Dendrocalamus luteus resembles D. bengkalisensis Widjaja (Widjaja, 1997) but differs in having white to brown culm sheath hairs, lobe-like leaf sheath auricles, and brownish and whitish hairs below the culm node (in contrast, D. bengkalisensis has consistently white culm sheath hairs, rounded 0.5-1 mm high leaf-sheath auricles, and is glabrous below the culm node). - TYPE: Sumatra, Jambi Province, Batanghari Subdistrict, Sei Bahar (now Muaro Jambi District, Sei Bahar Subdistrict), 8 July 2006 Widjaja 8128 (holotype BO [one specimen over three sheets], accession No. BO-1934223 (shoot), BO-1934220 (leafy branch), BO-1934224 (inflorescence); isotype K). (Fig. 1) Culm yellowish green to yellow; brownish and whitish hairs and white waxiness below the node when young, which disappears at maturity. Branch complement with a dominant primary branch which becomes very long (up to 5 m) and overarches onto neighbouring trees or even droops to the ground; culm and branch tips that droop to New Dendroccilamus from Sumatra 77 4 cm 2 cm Fig. 1. Dendroccilamus luteus Damayanto & Widjaja. A. Culm shoot. B. Detail of upper part of culm sheath, showing rounded auricle with bristles. C. Leafy branch. D. Leaf sheath-blade junction, showing auricle with bristles. E. Inflorescence. F. Glume. G. Lemma. H. Palea. I. Pistil surrounded by six stamens with free filaments, without lodicules. J. Detail of pistil. Drawn by Wahyudi Santoso from Widjaja 8128 (BO). 78 Card. Bull. Singapore 69(1) 2017 the ground occasionally rooting and forming a new clump. Culm sheaths 15.9-16.9 x 14.5-15.4 cm, orange in young shoots, covered by white wax on the upper part and with dense appressed white to brownish hairs at the base, sheath margin with white hairs along the apical part which are gradually replaced by brownish hairs (up to 0.3 cm long) toward the basal portion, eventually deciduous; auricles rounded, 0.4-0.5 cm high, bristles many and long, 2-2.8 cm long; ligules dentate, 0.2-0.4 cm high, bristles few, 0.4-0.6 cm long; blade spreading then reflexed, narrowly lanceolate, 10.7-12.4 x 2-2.7 cm. Leaf 23.2-253 x 2.3-4.5 cm, midrib base orange to yellow, pubescent on lower surface; auricles lobe-like, less than 0.5 mm, bristles 0.9-1.7 cm long; ligules entire, 1-2 mm high, glabrous. Inflorescences with 1-2 florets in each pseudospikelet, without a terminal vestigial flower; empty glumes 2; lemma 6-7 mm high; palea keeled at the apex, 8-8.5 mm long; stamens six, up to 4 mm long, anthers yellow with free filaments; ovary obovoid with thickened and hairy apex, produced into long hairy style 6-7 mm long and ending in a white plumose stigma. Distribution. Sumatra, Jambi Province and South Sumatra Province, in the Indonesian Ecosystem Restoration area. Ecology. This species forms the dominant growth in secondary forest along the road at around 60 m asl. Following logging of the forest in this area in 1991, this species has become abundant, with a suggestion from the local people that it is being dispersed by elephants. Notes. The epithet luteus (meaning yellow) refers to the colour of the shoot, culm, base of the leaf blade and midrib, and anthers. Table 1 compares D. luteus to its closely related species. Vernacular names and uses. Unknown. Additional specimens examined. INDONESIA: Jambi Province: Batanghari District, Bajubang Subdistrict, Hutan Harapan, Jembatan Jengkol, 3 Apr 2013, Wardi et al. BOHK 402 (BO); Batanghari District, Bajubang Subdistrict, Harapan Rainforest, 500 m before Jembatan Jengkol (Jengkol bridge) from office, 02°10'23"S 103°19'54"E, 2 Mar 2016, Damayanto & Widjaja 02 (BO), Damayanto & Widjaja 03 (BO), Damayanto & Widjaja 04 (BO); Batanghari District, Bajubang Subdistrict, Harapan Rainforest, 1 km after Jembatan Jengkol from office, 02°1F17.5"S 103°20'22.7"E, 2 Mar 2016, Damayanto & Widjaja 05 (BO). South Sumatra Province: Musi Banyuasin District, Batanghari Leko Subdistrict, Hutan Harapan, around Bato Nursery, 7 Apr 2013, Wardi et al. BOHK 478 (BO); Musi Banyuasin District, Lubuk Bintialo Subdistrict, Harapan Rainforest, Merajang, 02°18'08.1"S 103°17'48.0"E, 3 Mar 2016, Damayanto & Widjaja 12 (BO), Damayanto & Widjaja 13 (BO), Musi Banyuasin District, Lubuk Bintialo Subdistrict, Harapan Rainforest, Near Danau Fokus 3, 02°18'08.1"S 103°17'48.6"E, 4 Mar 2016, Damayanto & Widjaja 14 (BO). New Dendroccilamus from Sumatra 79 Table 1. Dendrocalamus luteus Damayanto & Widjaja compared to closely related species. D. luteus D. bengkalisensis D. buar D. bait Shoot Orange with white Orange with white Orange with Orange with white hairs and white hairs or glabrous white hairs and hairs on the upper wax on the upper on the upper white wax on the sheath, white wax sheath sheath, white wax upper sheath not seen not seen Culm colour Yellowish green to Green Green Green yellow Culm sheath Rounded, 0.4-0.5 Rounded, 0.7-1 Rim like and Rounded, bristles auricles cm high, bristles cm high, bristles crisped to blade 1.0-1.5 cm long 2-2.8 cm long 0.7-2.5 cm long base, bristles 0.9-1.8 cm long Culm sheath Dentate, 0.2-0.4 Denticulate, up Denticulate, Irregular, up to 1 ligule cm high, bristles to 0.2 cm high, irregular, 0.7-1.9 cm, glabrous few 0.4-0.6 cm bristles up to 0.2 cm high, bristles long (-0.5) cm long 0.4 -1.5 cm Culm sheath Spreading when Reflexed Erect to reflexed Erect to reflexed blade young, reflexed when mature Culm sheath White hairs Absent Absent Absent margin and replaced by brownish hairs Lower leaf Pubescent Pubescent Glabrous Glabrous surface Leaf sheath Lobe-like, bristles Rounded lobes, Small to incon¬ Small to incon¬ auricles 0.9-1.7 cm long bristles 0.9-1.7 spicuous, bristles spicuous, bristles cm long 0.1-0.2 cm long 0.4-0.6 (-1.2) cm long Palea Keeled No data Not keeled Not keeled ACKNOWLEDGEMENTS. We would like to thank the Director of the Herbarium Bogoriense (BO), Botany Division, Research Center for Biology, LIPI for allowing the consultation of research material and the use of research facilities. We would like also to thank the Director and staff of Harapan Rainforest (Indonesian Ecosystem Restoration) for permission and funding to collect specimens. The Asian Logging Company, who were the previous owner of the Indonesian Ecosystem Restoration, kindly issued a permit to collect bamboo in their area. Thanks are due to Messrs. Zelvin, Fery and Edi for helping to collect the specimens and Mr Wahyudi Santoso (BO) for preparing the illustration. We sincerely thank Dr Wong Khoon Meng (SING) for reviewing this manuscript before it was submitted. 80 Card. Bull. Singapore 69(1) 2017 References Widjaja, E.A. (1997). New taxa in Indonesian bamboos. Reinwardtia 11(2): 57-152. Widjaja, E.A., Rahayuningsih, Y., Ubaidillah, R., Maryanto, I. & Rahajoe, J.S. (eds) (2014). Kekinian Keanekaragaman Hayati Indonesia 2014. Jakarta: LIPI Press.