Dendrocalamus sp. (BD, IN)

Specimen: BS-0791 [E4] (living plants), raised from seeds, the seeds from FMXG, Yunnan, China, collected Apr. 2014, plants originally collected from Bengal (Bangladesh, or West Bengal, India), seeds received as "Dendrocalamus longerinternodium, 南亚龙竹 (nán yà lóng zhú)", May 2014.

Characteristics: Habit unicaespitose, dense clump. Rhizome pachymorph, short. Culms straight, erect, slightly bending outwards above, and arching, ultimate length and diameter not known (current size estimated at over 12 m long by 6 cm in diameter in June 2021). Young shoots emerge from June. Culm-internodes terete, to 45 cm long (on a culm with 6 cm in diameter), green, initially thinly farinose and brown-fuzzy, becoming glabrous with age; walls thick. Culm-nodes not or slightly prominent; nodal line horizontal, dipping slightly below the bud; sheath scar not or marginally protruding; supranodal line obscure, without a ridge, 10–15 mm above the nodal line; with a narrow, ca. 7 mm high sericeous whitish band below the nodal line when young, with a ca. 10 mm high sericeous whitish band between the nodal line and supranodal line; aerial roots present on the basal and lower nodes. Branch-buds solitary, large, ovate, broader than tall, from the basal node up. Branches several, unequal, the central one dominant, usually unbranched on the basal and lower culm; branching intravaginal; rebranching. Culm-leaves deciduous. Culm-leaf sheaths parabolic, ca. 22 cm wide at the base, 18 cm long, about two-thirds as long as the internode, papery, green with an orange tint when young, straw-colored when dry, with a few patches of appressed short dark hairs; apex rounded, with the middle part truncate or slightly concave-depressed; margins long pale to brown ciliate. Culm-leaf auricles none. Culm-leaf ligule ca. 3–5 mm high, brown, fringed or ciliate. Culm-leaf blades papery, deflexed to reflexed, persistent, narrowly triangular; blade base half as wide as the truncate sheath apex, with a few brown hairs near the blade base. Foliage-leaves (5) 8–10 (14) per branchlet. Foliage-leaf sheaths keeled on the back, light green when young, covered with short soft pale hairs, becoming glabrous; apex truncate; margins eciliate. Foliage-leaf auricles none. Foliage-leaf ligule conspicuous, margin fringed. Foliage-leaf blades lanceolate, 20–35 × 2.7–6 cm, glabrous above, puberulent beneath, dull mid-green on both surfaces; base rounded to wedge-shaped, often unequal; apex attenuate; margins antrorsely scabrous; midvein proximally distinct and light green beneath; pseudopetiole ca. 3 mm long.

Seed viability: Unknown, viability is assumed to last at least several months.

Seed weight: 10 g ≈ 185–195 dried spikelets (husk-wrapped seeds).

Seed germination: (1) Tests 140516, 140815, germination rate 50–80%. — (2) pH tolerability test (Jul. – Sep. 2014): Seedlings do not tolerate a high alkaline growth medium.

Comments:

(1) Culm height 20–30 m, culm diameter 12–20 cm, internode length 40–95 cm, internode walls very thick, 3–5 cm, clumper; an unidentified giant Dendrocalamus species from Bengal (Bangladesh, or West Bengal, India); plants were brought to southern China where they flowered and produced seeds, which have been harvested and distributed (according to the seed supplier).

(2) An internode length of almost 1 m is rather long for a species of Dendrocalamus.

(3) The description above is based on a 7-year-old plant that has not yet reached its ultimate size.