Gigantochloa maneensis Q. M. Qin, N. H. Xia & J. B. Ni, 2023

Qin, Qiao-Mei, Tong, Yi-Hua, Zeng, Yi, Cai, Zhuo-Yu, Ni, Jing-Bo & Xia, Nian-He, 2023, Two new species of Gigantochloa (Poaceae: Bambusoideae) from Yunnan, China, Phytotaxa 616 (1), pp. 79-88 : 83

Gigantochloa maneensis Q. M. Qin, N. H. Xia & J. B. Ni , sp. nov., Figs. 1−2

Type:— CHINA. Yunnan, Mengla County, Menglun , cultivated in Xishuangbanna Tropical Botanical Garden , introduced from Man’e Village , 8 August 2017, Qiao-Mei Qin, Juan Chen & Su Li QQM-319 (holotype IBSC!) .

Diagnosis: — Gigantochloa maneensis is similar to G. callosa , but differs in the intranodes with a ring of white hairs (vs. glabrous), infranodal regions with a ring of white (vs. brown) hairs, culm leaf sheath without stripe (vs. with yellow stripes initially) and densely black- (vs. brown- and gray-) hispid abaxially, erect (vs. reflexed) culm sheath blades, oblong (vs. rhombic) culm sheath auricles, 6–7 mm (vs. ca. 10 mm) wide, and sparsely brown-hispid (vs. white-pubescent) foliage leaf sheaths ( Table 1 ).

Description:— Rhizomes pachymorph. Culms erect, ca. 10 m tall, 5–7 cm in diam., walls ca. 2.5 cm thick, lower nodes with a few verticillate aerial roots; internodes 20–30 cm long, terete, greyish-green with yellow stripes, white-pubescent; nodes slightly prominent, intranode ca. 1 cm tall, with a ring of white hairs, infranodal region with a ring of white hairs. Branches 0.5–1.5 m long, developing from the 5 th –8 th node above the ground, numerous, dominant branches inconspicuous. Culm leaf sheath deciduous, leathery, nearly as long as internodes, densely brown-hispid abaxial surface with deciduous trichomes; blade erect, lanceolate, 1/3–1/2 as long as culm leaf sheath; auricles oblong, 6–7 mm wide and ca. 3 mm tall; ligule 2–3 mm tall, dentate. Foliage leaves 7–9 per ultimate branch; sheath sparsely brown-hispid, with deciduous trichomes; auricles absent; ligule ca. 2 mm tall; outer ligules ca. 2 mm high; petiole ca. 2 mm long; blades 13–30 cm × 1.5–3.0 cm, lanceolate, apex acuminate, glabrous, longitudinal veins 6–8 pairs. Pseudospikelets densely clustered at nodes of flowering branches, 8.5–11.0 mm long, with 3–4 glumes, 2 perfect florets and a terminal sterile floret consisting of only an empty; rachilla very short; lemma 7–8 mm long, apex mucronate, margins ciliate; palea 6.0– 7.5 mm long and ca. 1 mm wide, apex bifid, 2-keeled, keels and margins ciliate, 2 veins between keels, 1 vein on each side; stamens 6, filaments united into a tube, translucent; anthers yellow, 4–5 mm long, with an apical hairy mucro ca. 0.5 mm long; ovary subcylindrical with a slightly expanded, thickened and hairy apex, ca. 0.7 mm long; style terminating in a single hairy stigma, 7–8 mm long. Caryopsis ca. 6 mm long.

Distribution and Habitat: —This species is cultivated in Man’e Village, Menglun Town, Mengla County, Yunnan Province, and then introduced to Xishuangbanna Tropical Botanical Garden. Wild population has not been found so far.

Phenology: —New shoots October to November, flowering August to September.

Etymology: —The specific epithet is derived from the type locality, Man’e Village.

Additional specimens examined (paratypes): — CHINA. Yunnan: Mengla, Xishuangbanna Tropical Botanical Garden , 21°41’N, 101°26’E, elev. 570 m, 18 November, 2010, Ping-Yuan Wang C130036 ( HITBC) ; ibid., 12 October 2011, Ping-Yuan Wang C130092 ( HITBC).

Chinese vernacular names:—AENJfflfi (pinyin: màn é jù zhú).

Figures

FIGURE 1. Gigantochloa brachystachya. A. New shoot; B. culm leaf, abaxial view; C. culm leaf, adaxial view; D. part of leafy branch; E. flowering branch; F. pseudospikelet; G. glume I; H. glume II; I. lemma; J. palea, adaxial view; K. palea, abaxial view; L. stamens; M. apex of anther; N. pistil; O. one perfect floret and the terminal empty lemma: o1. lemma, o2. pistil and stamens, o3. palea, o4. terminal empty lemma. Drawing by Ding-Han Cui, A from the photo by Yi Zeng, B–O from the holotype.

FIGURE 2. Gigantochloa brachystachya. A. habit; B. flowering branches; C. culm shoot; D. branch complement; E. apex of culm leaf; F. part of leafy branch, adaxial view; G. part of leafy branch, abaxial view. Photos by Yi Zeng.