Bambusa duriuscula

Specimen: BS-0107 [E3] (living plant), Hainan, China, cult., received from M. S. as "Bambusa sp.", 23 June 2013.

Characteristics: Habit tight caespitose. Rhizome pachymorph, short. Culms straight, erect or slightly slanted, slightly bending above, 8–10 (10.9) m tall. Young shoots light green, conical; emerge from April to September. Culm-internodes terete, (35) 45–52 (62) cm long, dark green, dull, glabrous, scaberulous, not farinose; diameter 2–3.8 (4.0) cm; walls 0.3–0.5 cm at 1.5 m above the ground. Culm-nodes glabrous, not or slightly prominent; sheath scar marginally protruding 0.5–1 mm; supranodal line obscure, without a ridge, 4–6 mm above the nodal line; with a thinly white farinose ring below and above the sheath scar when young; aerial roots none. Branch-buds solitary, subrotund, pointed, from the basal node up. Branches several, 0.1–0.4 cm in diameter, the central one moderately dominant, 2 side branches subdominant, and smaller branches; 0.4–1.1 (1.7) m long; the first 3–4 (8?) nodes of the basal and lower culm unbranched; branching intravaginal; rebranching. Culm-leaves early deciduous. Culm-leaf sheath 9.5 cm wide at the base, 12.5 cm long, less than 1/3 of the internode length, rigid, light green to light orange-brown when young, light straw-colored when dry, with short appressed black hairs near margins; margins eciliate; apex subtruncate, slightly convex. Culm-leaf auricles subequal lobes, about 1 cm wide and 0.6 cm high, glossy dark brown when young, light straw-colored but slightly darker than sheath when dry; with short, up to about 10 mm long undulate pale bristles. Culm-leaf ligule about 1 mm high, entire. Culm-leaf blade papery, glabrous, usually persistent, stiffly erect; triangular, with rounded basal edges, the edges marginally overlapping the auricles; 3.3 cm wide near the base, 7.5 cm long (shorter on the basal culm), 3.0 cm wide at the junction with the sheath; light green to light orange-brown when young, of the same color as the sheath when dry; apex pointed; margins short pale ciliolate when young, antrorsely scabrous when dry. Foliage-leaves (5) 9–11 (12) per branchlet. Foliage-leaf sheaths mid-green to light green, glabrous; margins eciliate. Foliage-leaf auricles brown lobes with several, about 5–8 mm long, spreading pale bristles. Foliage-leaf ligule very short, inconspicuous, entire. Foliage-leaf blades linear-lanceolate, (7) 11–16 (21) × 1.0–1.6 (2.5) cm, glabrous on both surfaces, dark green above, pale to bluish green beneath; base rounded to wedge-shaped, sometimes slightly asymmetrical; apex attenuate; margins antrorsely scabrous; midrib proximally slightly prominent on both surfaces, mid-green to light green beneath; pseudopetiole 2–3 mm long. Flowers seen; seeds unknown.

Comments:

(1) The vegetative characteristics of BS-0107 do not match sufficiently but are closest to those of Bambusa duriuscula.

(2) BS-0107 should also be compared to Bambusa concava from Hainan; however, a description of Bambusa concava has not yet been included in the Flora of China (Bambusa, in Flora of China [#1303], accessed 24 May 2021).

(3) On 12 August 2024, a few flowering branches were observed at the apex of a tall single culm.

(4) Young shoots are not palatable, even after boiling twice, and are therefore not used as food.

Specimen: BS-0108 [W4] (living plant), Hainan, China, cult., received from M. S. as "Bambusa sp.", 23 June 2013.

Characteristics: Very similar to BS-0107, but culms a little less tall,  to 9 m, culm-internodes on average a bit longer, (40) 55–65 (77) cm, though smaller in diameter, 1.8–3.0 cm, foliage-leaf auricles with longer bristles, to 1.5 cm long, and foliage-leaf blades a little larger, 14–19 (24) cm × 1.5–1.8 (2.7) cm. Flowers and seeds are unknown.