Embedded Files
— BAMBOOS OF THAILAND — ONLINE VERSION OF 1 JANUARY 2021 — LATEST UPDATE OF 21 SEPTEMBER 2025 —
Melocalamus sp.
"Dinochloa mengyangensis" (BS-0005): Young shoot (left); node, showing a dormant bud and a "girdle" below, after having removed the persistent culm-leaf by hand (center); node, developing thin young branches, showing a dark corky ring at the nodal line, a white fuzzy ring on the internode below the nodal line (right)
Specimen: BS-0005 [C6] (living plant), received at Bambusetum Baan Sammi as "Dinochloa mengyangensis, 勐养藤竹 (měng yǎng téng zhú)" from FMXG, China, on 21 July 2011.
Characteristics: Habit tight caespitose, irregular. Rhizome pachymorph, short or slightly elongated. Culms over 10 m long [ultimate length and diameter in a mature clump not yet known], ascending or more or less erect below, bending from the lower culm above and scandent, not twining. Young shoots light green, appearing glabrous, with strongly erect culm-leaf blades; emerge from April/May. Culm-internodes terete, 35–50 (60) cm long, green, initially scattered with short soft white fuzz, not farinose, becoming dull and rough, except the section covered by the culm-leaf which is glossy and smooth; diameter 1–1.5 cm, gradually but markedly increasing toward nodes for a length of about 3 cm, solid throughout (culms and branches). Culm-node prominent, nodal diameter one and a half times, or little more, the diameter of the middle part of the adjacent internode; with a broad white fuzzy ring below the nodal line when young, long-lasting, fading when old; nodal line an elevated corky ring; girdle, a broad persistent rough dark brown ring (remnants of basal culm-leaf sheath: from the margin of the sheath base to the sheath scar), about 8 mm high on the bud-bearing side, 5 mm on the opposite rear; the nodal section between the nodal line and the supranodal line initially thinly overcast with a white mealy-waxy deposit which is covered, hence not visible, by the (almost) persistent culm-leaf sheath, this deposit early disappears when the sheath has been removed or is decaying, leaving a glabrous and smooth surface; supranodal line with a ridge and clearly discernible; aerial roots none. Branch-bud solitary, from the basal node up, large, as broad as the nodal diameter, bud margins eciliate. Branches several or many, thin, subequal, often with a single slightly thicker and much longer branch; occasionally a single very dominant branch may develop, this one nearly of the same diameter as the main culm, or of the same diameter, or even markedly thicker, and replacing the main culm; branching usually from the lower culm or mid-culm up; extravaginal or infravaginal; rebranching. Culm-leaves usually less than half the length of the internode, usually persistent, sometimes decaying on the culm or loosely attached to the internode and dropping off late. Culm-leaf sheaths about 5 cm wide at the base, 12–15 cm long, a third as long as the internode, or slightly longer, rigid, brittle, light green and thinly covered with short white fuzz when young, light straw-colored and glabrous when dry; margins eciliate; apex rounded. Culm-leaf auricles none, not bristly. Culm-leaf ligule low, 1 mm or less, entire, eciliate (perhaps initially ciliolate). Culm-leaf blades caducous, papery, stiffly erect, glabrous, green when young, straw-colored when dry, narrowly lanceolate, less than half as long as the sheath at mid-culm, about 8 mm wide at the junction with the sheath; margins smooth; apex long pointed. Foliage-leaves 7–9 (13) per branchlet. Foliage-leaf sheaths not or slightly keeled, green when young, straw-colored when dry, glabrous; margins eciliate. Foliage-leaf auricles none, not bristly. Foliage-leaf ligule low, 1 mm or less, pale orange when young, entire, eciliate. Foliage-leaf blades (12) 13–20 (23) × (3) 3.5–4 (5) cm, lanceolate, glabrous on both surfaces, mid-green to dark green, glossy above, dull beneath; base rounded to wedge-shaped; apex attenuate, often twisted; margin on one side smooth, on the other side antrorsely scaberulous; midrib proximally prominent beneath; pseudopetiole 2–3 mm long.
Comments:
(1) The characteristics of BS-0005 hardly match those of Dinochloa mengyangensis L. Gao, so it cannot be assumed that both represent the same species.
Description: "Culms scrambling, 20-50 m long, 2.3-4.2 cm DBH, Internodes 35-50 cm long, hollow, with the culm walls 3-6 mm thick. Numerous branches emerge in clumps at each node of the culms, with the central branches equal to the culms in diameter, replacing the main culms to grow. Sheaths late deciduous, with the oral setae on the auricles, 6-9 mm long and the blades erect. Leaves 6 to 10 emerge at the branchlets, with the leaf auricles well-developed and the oral setae 1-2 cm long, and the leaf blades large-sized, 20-35 cm long, 2-3.5 cm wide. … [Flowers and seeds described]." — B. Lan [兰冰 (lán bīng)], Compendium of Bamboo Fruits and Seedlings, Kunming, 2010: p. 13 [#1179].
Images: B. Lan, l.c., 2010: fig. 6.1.-1–6.1.-5 [#1179] (flowering branch, seeds, seedlings, young shoots, habitat).
Distribution: Southern Yunnan: Xishuangbanna (Sipsongpanna), near Jinghong, China.(2) A valid publication of the name, Dinochloa mengyangensis L. Gao, is not known. This name was published in B. Lan, l.c., 2010: p. 4, 13. Specimens with this species name are not listed in the Chinese Virtual Herbarium.
(3) Not a single species of Dinochloa is listed in the Flora of China (accessed 23 July 2017 [#1303]). It has been argued that Chinese botanists have doubts about the identification as Dinochloa species, which is why the species were not included in the Flora of China. Four species of Dinochloa from China are listed in the World Checklist of Bamboos and Rattans, 2016 (Dinochloa p. 85–88) [#1221]. These comprise three species from Hainan, Dinochloa orenuda McClure, Dinochloa puberula McClure, Dinochloa utilis McClure, and one species from Yunnan, Dinochloa bapoensis Hsueh f. & Y. M. Yang, published in J. W. China Forest. Sci. 42(1): 6 (2013).
(4) In 2022, an extensive paper by Jing-Xia Liu, Zu-Chang Xu, Yu-Xiao Zhang, Meng-Yuan Zhou, and De-Zhu Li was published, which shed light on the identities of the above three taxa from Hainan published as Dinochloa: J. X. Liu & al., The identity of Dinochloa species and enumeration of Melocalamus (Poaceae: Bambusoideae) in China, Plant Diversity, July 2022, accessed 31 August 2022 [#1372]. The three species were transferred to Melocalamus, i.e., Melocalamus orenudus (McClure) D. Z. Li & J. X. Liu, as "orenuda", Melocalamus puberulus (McClure) D. Z. Li & J. X. Liu, as "puberula", and Melocalamus utilis (McClure) D. Z. Li & J. X. Liu, respectively. However, the aforementioned single species from Yunnan, Dinochloa bapoensis Hsueh f. & Y. M. Yang, was not mentioned in J. X. Liu & al., 2022 [#1372]. Unfortunately, I have no access to the relevant paper: Study on the Bamboos in Dulong River Area, by Yang Yu-ming, Du Fan, Shi Ming, Zhao Yi-he, Xu Tian, & Wang Juan, in Journal of West China Forestry Science (西部林业科学), vol. 42 (1), 2013, pages 1–9. A comparison of the characteristics of Dinochloa bapoensis with BS-0005 is therefore not possible for me.
(5) The plant with specimen number BS-0005 grown at Bambusetum Baan Sammi develops scrambling but not twining culms (the latter a spiral growth habit characteristic of Dinochloa species) and has other vegetative characteristics that apply to Melocalamus species: prominent culm-nodes with a ring of (white) powdery-waxy deposit below and above the nodal line. Therefore there is good reason to believe that BS-0005 is a species of Melocalamus rather than Dinochloa.
(6) I have compared the vegetative characteristics of BS-0005 with those in the descriptions of all known Melocalamus species from China (J. X. Liu & al., The identity of Dinochloa species and enumeration of Melocalamus … in China, Plant Diversity, July 2022 [#1372]; and Flora of China [#1303], both accessed 31 Aug. 2022), but could not find a satisfactory match. The culm-leaf of Melocalamus elevatissimus has a sheath with an erect blade and no auricles as in BS-0005, but other vegetative characteristics are different: In BS-0005, the culm-leaf sheath apex is rounded and has no projections on either side as in M. elevatissimus; internodes of culms and branches are solid throughout in the former, but the latter has internodes with a small lumen and are also much longer; culm-nodes are prominent in the former but not so in the latter; culm-leaf sheaths are farinose and otherwise glabrous in the former but not hispid as in the latter; culm-leaf blades are glabrous in the former but pubescent in the latter; foliage-leaf blades are lanceolate (not oblong) and much smaller in length and width in the former as compared with the latter. There is no other conclusion than that BS-0005 is clearly another, as yet unidentified, species and not Melocalamus elevatissimus.
Page updated
Google Sites
Report abuse