Bambusa nghiana
Bambusa nghiana V. T. Tran, Adansonia 43(19), 2021: 218.
Type: Vietnam, Thanh Hoa Province, Quan Son District, H. N. Nguyen HNN0067, holotype (DLU); cf. V. T. Tran, Adansonia 43 (19), 2021: 218 [#1371].
Thai names: ไผ่ซี้ (phai si), ไม้ซี้ (mai si) in Trat Province; ไผ่ปล้องยาว (phai plong yao) at Pang Sida National Park (อุทยานแห่งชาติปางสีดา) of Sa Kaeo Province; ไผ่นวล (phai nuan).
Vietnamese name: Lùng.
Distribution: THAILAND (East): Provinces of Prachin Buri and Trat, common along streams in dry evergreen forests at low altitudes, in evergreen forests at ca. 165 m altitude, and along roads and forest edges at ca. 700 m altitude; cf. W. Arthan & al., in Kew Bulletin, 2023 [#1396]. Also recorded from the central and eastern provinces of Prachin Buri, Sa Kaeo, Chanthaburi, Rayong, and Trat as wild (acc. to Mu Chakkrapong on Facebook, 19 Sep. 2017), and from Nakhon Nayok, wild, in forests (acc. to Mu Chakkrapong on Facebook, 2 Oct. 2021, and pers. comm., Facebook, 2 Oct. 2021). — VIETNAM (Northern): Quan Sơn District of Thanh Hóa Province: along roads and forest edges.
Descriptions:
(1) "Woody bamboo, rhizomes pachymorph, short-necked. Culm erect, plain color, green when young maturing to yellow, 13-15 m tall, 7-10 cm in diameter. Culm internode terete, basal internode covered with appressed pale hairs with a consistent narrow ring of dense appressed hairs at each node, with a slight white-waxy bloom just above, 60-80 cm long, or up to c. 100 cm long; wall thin, often less than 9 mm thick. Branches usually absent on lower culm, branches at mid-culm with the primary axis dominant in size with 2 or several higher-order subequal branches from its base. Culm sheaths on mature culm 25-35 cm long, pale green, infused with white green or yellow green at the top and dense black hairs at the base; basal part at the sheath insertion with a 2-3 mm long, narrow ring-like band of dense dark brown hairs 2-3 mm long; blade 5-8 cm long, broad triangular, erect, not tightly appressed against the next sheath or internode[,] green, with a slight white-waxy bloom on abaxial side, with 1-2 cm long pale brown bristles at the base of the margins; auricles 7-10 mm high, protruding, 1-2 cm long and slightly upcurved at the end, purplish brown with sinuous bristles on the edge 5-10 mm long, ligule a leathery low subentire rim 2-2.5 cm high with narrow triangular margin teeth. Leaves 18-20 × 2.9-3 cm, green on the adaxial side and white green on the abaxial side, glabrous on both surface; auricles with a conspicuous laterally spreading narrow lobe 0.5-1 mm high and 1-2 mm long, upcurved at the end, margins with spreading bristles 1-2 cm long; ligule inconspicuous; sheath glabrous. … [flowers and seeds described]". — V. T. Tran, in Adansonia 43 (19), 2021: p. 217-221 [#1371].
(2) "Perennial arborescent bamboo, unarmed. Rhizomes a pachymorph with short necks, sympodial; forming a dense clump with relatively well-spaced culms. Culms erect, up to 15 m tall, tips arching to drooping; nodes not swollen; nodal line horizontal, more or less the same diam. as the adjacent internodes, with a ring of patent rusty brown hairs; supranodal ridge inconspicuous, with a band of pale to white hairs above; aerial roots absent; internodes dull green, 50 – 150 cm long, 3 – 8 cm in diam., covered with white to rusty brown hairs and thick white wax when young, greyish-green and glabrous when mature; walls thin, 4 – 8 mm thick mid-culm. Branch buds at each culm node solitary. Branches developing from the base or from around mid-culm upwards. Mid-culm branch complements with several branches per node; middle branch dominant, 1/3 – 1/2 the diam. of the main culm; 2 associated, smaller, secondary branches; basal, smaller branchlets few. Culm leaves deciduous; sheaths purplish to brownish-green when young, greyish to yellowish-green when mature, 15 – 35 cm, covered with thick white wax, and brown to black hairs when young, margins scarious, base of outer margin with a slight projection below the point of attachment; blades spreading or patent, occasionally deflexed, purplish-green when young turning green when mature, broadly triangular to lanceolate with some constriction at the base, 4 – 8 cm long, base less than 1/3 width of sheath; auricles present and contiguous with the base of the blade, protruding laterally from the sheath margins, lobe-like, up to 2 cm long, more or less unequal, oral setae present, bristles 0.5 – 1.5 cm long; ligules a leathery, low, subentire rim, 2 – 5 mm high, margin with teeth 1 – 8 mm long, irregularly denticulate to bristly. Foliage leaves with sheaths 3 – 6.5 cm long, glabrous; blades lanceolate, 15 – 35 × 1 – 3.8 cm, apex acuminate, glabrous on both sides, abaxially glaucous; auricles conspicuously lobed, lobes 1 – 2 mm long, margins with bristles up to 1 cm long; ligules inconspicuous. … [flowers and seeds described]". — W. Arthan & al., in Kew Bulletin, 2023 [#1396].
Images: Photos and line drawings in V. T. Tran, l.c., 2021: p. 219-220 [#1371]; photos in W. Arthan & al., l.c., 2023 [#1396].
Uses: Locally in Vietnam: Shoots for food, culms for house construction and handicrafts. Locally in Thailand: Shoots edible, and said to be eaten by locals; culms for woven bamboo hats (Mu Chakkrapong, l.c.) and other handicrafts.
Specimens: BS-0599 [C4-R03] (living plant), received as "ไผ่เกรียบ (phai kriap)" from the cultivated stock of Nana Phan Nursery, Prachin Buri, 1 Dec. 2010, said to originate from the mountains of nearby Khao Yai National Park where this bamboo grows wild, abundant, and widespread. — BS-0599A (seeds of BS-0599), seedlings raised at Bambusetum Baan Sammi in early April 2021.
Bambusa nghiana (BS-0599): From left to right: (1) Young shoot, (2) hairy lower part of a young culm-leaf sheath, and apex with rim-like bristly auricles, (3) culm node with a ring of patent hairs, (4) habit
Characteristics: Habit open caespitose. Rhizome pachymorph, moderately long, up to about 30 cm. Culms 22 m long, the lower half to two-thirds straight and almost stiffly erect, then bending and extending into a long, thin, whip-like scandent but not drooping tip. Young shoots pale green and whitish, with scattered black hairs, conspicuous black rim-like auricles, and spreading mid-green rigid culm-leaf blades; emerge from June. Culm-internodes terete, 50–80 (101) cm long, green, when young with large patches of minutely short fine silvery-white pubescence, otherwise glabrous, becoming white waxy-mealy, when old dull green with a bluish tint, smooth on the upper part, slightly rough on the lower part; diameter to about 6 cm at base, increasing 25% towards mid-culm (e.g., 1st internode 5.0 cm in diameter, 8th internode 5 m above ground 6.4 cm in diameter), then decreasing; very thick-walled to thick-walled only up to about 1 m culm height, moderately thick-walled to thin-walled on lower and mid-culm throughout (→ table with culm size dimensions). Culm-nodes smooth, flat; sheath scar initially with 4–5 mm long, soft, fur-like silvery-white to glossy black hairs, becoming brown and remaining when old; supranodal line not clearly discernible; above sheath scar with a narrow white ring, or with a long patch faded to pale straw-color, irregularly 3–14 cm long; below sheath scar often with a shorter patch faded to pale-straw color, irregularly up to 3 cm long; aerial roots none. Branch-buds solitary, from the basal node up, all remaining dormant for a long period, usually from shooting in June until March or April, rather large except on the basal culm, broader than tall, to 66 mm wide by 33 mm height on the mid-culm (about 15th node), usually broader than half the nodal circumference on the lower, mid and upper culm. Branches several, on upper culm usually about 8, unequal, often 1–3 somewhat dominant and of about half the diameter of the main culm, the other thin; from mid-culm up, occasionally developing a single branch almost as thick as the main culm; basal culm, lower culm, and often mid-culm (up to the 5th–11th node) remaining unbranched; branching intravaginal. Culm-leaves deciduous. Culm-leaf sheaths about as long as wide, 18–22 cm wide at the base, 16–22 cm long, rather short as compared to internode length, coriaceous, the upper part of the sheath near apex pale green with orange tint when young, and glabrous, the main part of the sheath bluish when young (no removable deposit, not farinose) and densely scattered with short stiff irritating black hairs, a few centimeters high section of the basal part of the sheath (and covering node) covered with long soft fur-like silvery-white easily removable hairs which directing downwards, and the basal sheath margin with persistent silvery-brown soft hairs (remain as sheath scar attached above the nodal line after the sheath dropped off), the dried sheaths light straw-colored and scattered with short blackish hairs; margins eciliate, smooth; apex rounded, with its 3–6 cm wide central part slightly convex-raised. Culm-leaf auricles 6–7 cm long narrowly corrugated and waved blackish rims, 0.3–0.5 cm high, adnate to the blade base, height gradually increasing towards the rounded ends, which protrude ca. 5 mm from the sheath margin; the margin of the auricles with fine erect silvery-white bristles 5–8 mm long. Culm-leaf ligule leathery, low, less than 1 mm high, subentire or denticulate. Culm-leaf blades rigid, green, caducous, strongly reflexed, broadly lanceolate to triangular, adaxially with very short rigid silvery-white hairs from the base towards about half length of the blade, otherwise glabrous, abaxially glabrous throughout; blades of basal culm-leaves very short, 3 × 1.2 cm, junction with sheath apex 1.2 cm wide, culm-leaf blade of the 5th node above the ground 10 × 2.5 cm, junction 2.2 cm, of the 8th node 21 × 5.5 cm, junction 3.7 cm. Foliage-leaves (5) 8–9 (16) per branchlet. Foliage-leaf sheaths rounded, green, glabrous; margins eciliate. Foliage-leaf auricles green conspicuous lobes, 7 × 1.5 mm, spreading, protruding; margins with 10–13 mm long, white, more or less radiate, straight bristles. Foliage-leaf ligule less than 1 mm high, orange when young, margin denticulate with several erect ca. 3 mm long early caducous white bristles; outer ligule a low ridge. Foliage-leaf blades (10) 22–32 × 3–6 cm, broad-lanceolate, sometimes asymmetrical, glabrous on both surfaces, medium green and almost glossy above, glaucous beneath; base typically cordate to rounded, terminal blade(s) rounded to wedge-shaped; apex attenuate; one margin antrorsely scabrous, the other antrorsely scaberulous; midrib proximally prominent on both surfaces, yellowish green below; pseudopetiole 1–2 mm long. Flowers known [not dissected], possibly proterandrous or adichogamous; seeds known. Pseudospikelets 2–2.5 cm long, in tufts of 1–6 (10) on leafless branches. Style long and thin; stigmas 1 or 2 (?), long, plumose, pinkish. Stamens 6, pinkish; apex apiculate; filaments free, whitish. Seeds (caryopses) with the husks (palea, lemma) persistent, fusiform, ca. 10–12 mm long, 4–5 mm wide, grooved; apex acute; pericarp thin, hardened, strongly adnate.
Bambusa nghiana (BS-0599): Flowering branch (left), seeds (BS-0599A) wrapped in husks (center), seedlings (BS-0599A) on 9th day after seeding (right) — left photo by courtesy of Che
Flowering and seeding: The specimen, BS-0599, was not perceived as flowering until late March 2021. Since all the flowering occurred in the upper parts of the plant, and all the branches were entangled with tall trees and other bamboo plants, the flowering was not immediately noticed. Presumably, flowering began in February or early March. In early April 2021, it could not be said whether the flowering would be sporadic or gregarious, but by mid-April, it became clear that the latter was happening. Spikelets were found on the ground in late March, and many of them contain seeds. With the start of the rainy season in April/May, numerous seeds germinated on the ground, and seedlings developed. The mother plant died soon thereafter.
Seed weight: 20 seeds weigh 1.31 g → ≈15 seeds/g.
Seed germination: 10 seeds laid on moistened coir dust on 31 March 2021, 19–32 °C day, diffuse light, 18–28 °C night, atmospheric humidity 60–99%, 6 coleoptiles emerged by the 5th day, the first leaves developed by the 8th day; a germination rate of over 50% can be expected (test 210331).
Seed viability: unknown; viability could only be a few weeks. Seed germination trials were carried out by three people from Europe, Central America, and South America; each person received 15 seeds 1–2 and 2–3 months after harvest, respectively. None of these seeds germinated. While there can be many reasons for unsuccessful germination, I would not rule out that the seeds of BS-0599 lack dormancy and therefore only have a short lifespan.
Cultivation requirements: easy-growing, thrives well in heavy, moist soil with good drainage, and in partial shade.
Comments:
(1) Prior to flowering, BS-0599 was assumed to belong to Melocalamus or Maclurochloa as they shared similar vegetative characteristics, e.g., growth habit, branch complement, shape and size of culm-leaves, conspicuous bristly auricles, inconspicuous ligule, hairy sheath scar-ring.
(2) When flowers and seeds of this species were found in Thailand in 2019, it was soon found out that Bambusa is the appropriate placement, despite the vegetative characteristic of the branch complement in BS-0599 (which is uncommon if not hitherto unknown in Bambusa) (Mu Chakkrapong, pers. comm. Facebook, 23 and 25 Feb. 2019, 20 and 25 Mar. 2021).
