Bambusa nutans
Bambusa nutans Wall. ex Munro, Trans. Linn. Soc. London 26 (1), 1868: 92.
Thai names: ไผ่บง (phai bong) (Northern); ไผ่บงบ้าน (phai bong ban); ไผ่บงคาย (phai bong khai); ไผ่บงเล็ก (phai bong lek). — T. Smitinand, 2001 [#1003]; BKF [#1368].
Distribution: THAILAND (Central, North), wild and cultivated. — BHUTAN. — NEPAL. — INDIA (North, North-East). — BANGLADESH.
Culm size: Height 25 m, diameter 9 cm.
Descriptions:
(1) "A medium sized graceful bamboo. Culms 6-15 m high, 5-10 cm in diameter, loosely clumped, much-branched above, usually unbranched below, straight, green, smooth, not shining, white-ringed below the nodes; node slightly thickened, often hairy, lower ones bearing rootlets; internodes usually 25-45 cm long, thick-walled. Culm-sheaths 10-23 cm long, upto 30 cm wide at base, with appressed scattered black hairs on the back, base with soft deciduous hairs, top truncate; ligule ca.2 mm, entire to dentate; auricles 2, at the top of the sheath, large, wavy, unequal in size, one erect and the other decurrent, both fringed, with long curved bristles; base rounded, margin recurved, adaxial surface clothed with appressed brownish black hairs. Young shoots yellowish-green at apex. Sheaths covered sparsely with dark-brown and yellow hairs. Leaves 15-25 cm long and 2-3.5 cm broad, linear-lanceolate, acuminate at apex, rounded and usually oblique at base, upper surface dull green, lower surface glaucous; petiole 3-5 mm long; leaf-sheaths hairy when young, striate; auricle falcate with few long hairs. …" — K. K. Seethalakshmi & al., Bamboos of India, 1998: p. 62 [#1062].
(2) "… Rhizomes short; pachymorph. Culms erect; 600–1200 cm long; 40–70 mm diam.; woody; with aerial roots from the nodes. Culm-internodes terete; with small lumen; 35–45 cm long; mid-green. Culm-nodes glabrous, or pubescent. Lateral branches dendroid. Culm-sheaths 15–23 cm long; pubescent; with appressed hairs; with black hairs; truncate at apex; auriculate; setose on shoulders. Culm-sheath ligule 2.5–5 mm high; dentate. Culm-sheath blade triangular; 15–23 cm long; pubescent; acute. Leaves cauline. Leaf-sheaths striately veined; pubescent. Leaf-sheath oral hairs setose. Leaf-sheath auricles falcate. Ligule an eciliate membrane; obtuse. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.3–0.5 cm long. Leaf-blades lanceolate; 15–30 cm long; 25–35 mm wide; glandular. Leaf-blade midrib conspicuous. Leaf-blade venation with 14–20 secondary veins. Leaf-blade surface glabrous, or puberulous; hairy abaxially. Leaf-blade margins scabrous. Leaf-blade apex acuminate; antrorsely scabrous. … [flowers and seeds described]." — Kew GrassBase [#1335].
Characteristics: Bambusa tulda vs. Bambusa nutans: "B. tulda has shorter, slightly crooked culms with much thicker walls and faint to obscure yellow stripes towards the base. … the leaves of B. tulda are distinguishable by the much larger leaf sheath auricles with widely spreading setae. In addition the smaller of the two culm sheath auricles is generally narrower and taller than that of B. nutans, and there are fewer hairs inside the culm sheath blade." — C. M. A. Stapleton, Bamboos Nepal Bhutan I, 1994: p. 8.
Uses: Shoots for food, culms for construction.
Seed weight: ≈65,000 seeds/kg → ≈65 seeds/g [#1302].
Seed viability: Unknown, viability assumed to last at least several months.
Comments:
(1) There is some doubt if plants of true Bambusa nutans occur naturally in Thailand; plants might have been confused with Bambusa tulda, Bambusa teres (syn. Bambusa nutans subsp. cupulata), or Bambusa lixin. There are Kew Herbarium [#1333] records of two collections determined Bambusa nutans, one from a cultivated plant in Chiang Mai, and the other, a specimen with flowers, collected wild in the mixed deciduous forest from Phetchabun by T. Smitinand in 1951, with local name "bong".
(2) Plants seen in the Chiang Mai area and named "phai bong" appear to represent Bambusa tulda. (3) Several specimens (BS-0395 [FTS], BS-0311 [-], all living plants) were collected from different cultivated plants that might represent Bambusa tulda.
Specimen: BS-0450 [BBG] (living plant), received from cultivated stock from the USA, 1 June 2010.
Characteristics: Rhizome pachymorph, short. Culms erect. Young shoots light green, conical, with the culm-leaf blade slightly patent, emerge from June. Culm-internodes glabrous, smooth, mid-green. Culm-nodes not prominent, with a white ring below and above. Branches several. Culm-leaves 1/3 of the length of the internode, deciduous. Culm-leaf sheath green, with cream stripes when young, straw-colored when dry, sparsely covered with blackish, appressed hairs. Culm-leaf auricles large, unequal, wrinkled, with long pale, waved bristles. Culm-leaf blade erect. Foliage-leaves 4–5 (9) per branchlet. Foliage-leaf sheath glabrous. Foliage-leaf auricles small, with a few long, erect white bristles. Foliage-leaf blades small, (4) 9 (13) × (0.8) 1.2 (1.7) cm, mid-green and glabrous on both surfaces; base rounded to cordately rounded and slightly oblique; pseudopetiole short, 1 mm long.
Bambusa nutans (BS-0450): Culm-leaf, showing auricles
Specimens: BS-0037 [BBG] (living plant), northern Thailand, without precise location, cult., C. S. (#3098), 28 July 2011, started flowering Dec. 2014; BS-0037A [BBG] (seedlings, raised from seeds of BS-0037), the seeds collected in low quantity by ธ. บ., Boonthammee Bamboo Garden, Hang Dong, Chiang Mai, in Feb./Mar. 2015, 28 seeds were received on 6 Feb. 2015.
Seed weight: 1.0 g ≈ 45–50 dried spikelets (husk-wrapped seeds).
Seed germination: Unexpectedly, the germination process for these Bambusa seeds started late and resulted in a low germination rate of 25-30% (test 150208).
Comments: The determination as Bambusa nutans could not be confirmed so far.
Bambusa nutans (?) — (BS-0037A): Germinating seeds, 37th(!) day after sowing, the seeds took more than 3 weeks to sprout (left), seedling, 56th day (right)
Bambusa sp.: Habit (CM-002)
Specimens: BS-0233 [FTS] (living plant), บ้านป่าฝาง (Ban Pa Fang), Doi Saket District, Chiang Mai Prov., cult. "ไผ่บง" (phai bong); CM-002 (living plant, culm sheath), บ้านป่ายางปอย (Ban Pa Yang Poi), Pa Lan, Doi Saket District, Chiang Mai Prov., cult., "ไผ่บง" (phai bong), removed and destroyed in 2017.
Characteristics: Culm height over 10 m, diameter 5 cm. Culm-internodes thick-walled, solid on the basal or lower culm. Culm-leaf sheath densely covered with short brown hairs (not black as in B. nutans), apex rounded. Culm-leaf auricles large, bristly. Culm-leaf blade triangular.
Uses: Culms for construction.
Cultivation requirements: Easy growing in heavy, water-retentive soil with good drainage, exposed to full sun.
Provisional identification: This is certainly a species of Bambusa, similar to Bambusa nutans.
Comments:
(1) This species is frequently planted as a village bamboo in the Chiang Mai area.
(2) In Thai literature, phai bong is most often treated as Bambusa nutans.
Specimen: BS-0278 [BBG] (living plant), from a garden adjacent to Prof. Maxwell's garden, T. Chang Khian (ช่างเคี่ยน), A. Mueang, Chiang Mai, northern Thailand, C. S., 14 Sep. 2009.
Comments: BS-0278 has been doubtfully assigned to Bambusa nutans. The characteristics of BS-0278 indicate Bambusa tulda rather than Bambusa nutans.
Specimens: BS-0228-1 [BBG] (living plant), from Mr. Athit (อาทิตย์), Suan Ketsaton Athit (สวนเกษตรอาทิตย์), Mae Taeng, Chiang Mai, northern Thailand, received as "ไผ่ซางหม่น (phai sang mon), from Uttaradit (อุตรดิตถ์)", 5 Dec. 2009.
Comments:
(1) When the propagule (BS-0228-1) received from Mr. Athit later developed into a larger plant, it turned out to be neither a Sang Mon Bamboo nor a Dendrocalamus species, but a Bambusa species. Since Mr. Athit's garden (Suan Ketsaton Athit) has many very large Sang Mon Bamboo plants growing along a ditch, surely Mr. Athit knows Sang Mon Bamboo very well, and getting the wrong propagule was purely accidental.
(2) BS-0228-1 has been doubtfully assigned to Bambusa nutans. Internodes of BS-0228-1 appear to be scurfy or hairy when young (not glabrous), and culm-leaf sheaths are brown-hairy (not black). It could be Bambusa tulda, but BS-0228-1 does not have the very large culm-leaf blades in young shoots that are characteristic of Bambusa tulda.