Dendrocalamus fuminensis

Characteristics: Habit caespitose, tight clump. Rhizome pachymorph, short. Culms straight, erect or aslant below, bending outwards above and arching, 10 m long [ultimate length not yet known, assumed to grow at least 15 m long]. Young shoots conical; culm-leaf sheaths green, farinose; culm-leaf blades patent; emerge from March. Culm-internodes terete, 35–43 cm long, green, farinose, lower culms brownish green short-velvety and scattered with short soft white hairs when young; diameter 5 cm [ultimate diameter not yet known]; walls moderately thick. Culm-nodes flat or marginally prominent; nodal line horizontal, on the lower culm with brown velvety hairs, and with a very narrow white fuzzy ring just below the nodal line; sheath scar not protruding, but 1–3 mm high, glabrous; often with a narrow, ca. 4 mm high ring with short white appressed hairs between sheath scar and the supranodal line; supranodal line obscure or distinct, without a ridge, 8–11 mm above the nodal line; aerial roots present up to about 1 m from the ground, hard. Branch-buds solitary, very large, ovate, broader than tall, from the basal node up. Branches several to many, unequal, the central one very dominant (2/3 as thick as the main axis or thicker and very long, 5 m and more), 2 side branches subdominant, the other branches 1–2 m long and slender; branch development horizontal to ascending, but thicker ones ascending or upright in an acute angle; branching from the basal culm up; branching intravaginal; rebranching. Culm-leaves early deciduous. Culm-leaf sheaths parabolic, 5–6 cm wide near the base, 15–18 cm long, ca. half the length of the internode, leathery, pale green when young, yellowish straw-colored when dry, with very small dark dots when old, farinose and scattered with brown appressed hairs when young; apex rounded to subtruncate; overlapping margin of the sheath pale to brown ciliate, the other margin eciliate. Culm-leaf auricles low rims, glabrous, erect, slightly pleated, blackish, adnate to and contiguous with the basal margin of the blade, extending toward but not reaching the sheath margin, entire, but with a few short pale oral setae at the ends. Culm-leaf ligule convex rounded, ca. 5 mm high in the middle, blackish, with dark-colored fringes terminating into pale bristles. Culm-leaf blades papery (?), deflexed to reflexed, early caducous, lanceolate. Foliage-leaves about 7 per branchlet. Foliage-leaf sheaths green to orange green and covered with short soft white caducous hairs when young, becoming glabrous soon; apex truncate to rounded; margins short pale ciliate. Foliage-leaf auricles low brownish to blackish rims, ca. 0.5 mm high, margin eciliate. Foliage-leaf ligule rounded, brownish to blackish, ca. 1 mm high, margin with a few (possibly early caducous) short white bristles; contraligule a slightly raised dark-colored callus. Foliage-leaf blades lanceolate, glabrous above, puberulent beneath, becoming glabrous soon, 31–42 × 6–8 cm, green; base rounded to wedge-shaped; apex acuminate to attenuate; margins antrorsely scabrous; midvein proximally prominent and yellowish green beneath; pseudopetiole ca. 5–6 mm long and 5–6 mm wide. Flowers not seen. Fruit a caryopsis, ovoid, 2–4 (5) mm long, pericarp medium brown, glossy.

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

Seed weight: 10 g ≈ 200–220 dried spikelets (husk-wrapped seeds).

Seed germination: Seeds were laid on moistened tissue paper, in April 2012, 31–35 °C day temperature, diffuse light, 21–25 °C night temperature, atmospheric humidity >70%, the first shoot emerged after 10 days, germination rate low (<40%). Seeds may more frequently suffer from fungal infection than those of other Dendrocalamus species.

Comments: Habit, culm nodes and branches of Dendrocalamus fuminensis closely resemble those of Bambusa grandis and Bambusa valida, both of the subgenus Dendrocalamopsis. The culm-leaf auricles of these two Bambusa species are not lobe-like but rim-like, and therefore also similar to D. fuminensis. The culm-internodes of Dendrocalamus fuminensis in a young stage resemble those of Dendrocalamus asper.