Dendrocalamus dumosus

Specimen: BS-0406 [C4-R02] (living plant), on limestone rocks along the seaside of Satun (สตูล), southern Thailand, coll. by ธ. ล., received as ไผ่ตัน (phai tan), 10 Jan. 2010.

Characteristics: Habit tight to moderately tight caespitose. Rhizome pachymorph, short, distance about 7–12 cm between old and new culm. Culms widely arching, scandent, over 6 m long (→ table with culm dimensions). Young shoots conical; sheath green, covered with white mealy wax in mature plants, without hairs; culm-leaf blades deflexed; emerge from May to August. Culm-internodes glabrous, smooth, mid-green to dark green, 25–38 cm long, 1.5–2.2 cm in diameter, solid or with very small lacuna on culms and branches throughout, lacuna on lower culm, mid-culm, and branches not exceeding 2.0 mm. Culm-nodes slightly prominent, sheath scar a prominent corky ring, shiny black when young, dull light brownish when old. Branch-buds solitary, from the basal culm up. Branches on the lower culm typically none, 1 branch from the mid-culm up, 1/2 to 2/3 as thick as the main culm, elongating, upper culm with several thin shorter branches; branch nodes slightly prominent; first branch internode solid, all further branch internodes with small lacuna (lacuna 1–2 mm by branch internode diameter 4–5 mm); branching intravaginal. Culm-leaves deciduous. Culm-leaf sheath 4.5 cm wide near the base, 5.4 cm at the base, 13.5 cm long, 1/2 as long as the internode; thinly leathery, glabrous, without hairs, light green or yellowish green with a reddish tint towards the apex when young, light straw-colored when dry, thinly farinose in the upper one-third of 2–3 m tall young shoots, thus appearing bluish-white; apex horizontally truncate, 0.6 cm wide or little wider, junction with the blade about 1/3–1/2 of the apex width. Culm-leaf auricles rim-like, inconspicuous, very low, 0.5 mm high, blackish, entire, without bristles. Culm-leaf ligule low, about 1 mm high, blackish, margin entire or finely toothed, usually without bristles, or with very short, less than 1 mm high pale bristles, or rarely with 1–2 erect, very slender, much longer, soon caducous bristles at the edges of the ligule. Culm-leaf blade deflexed, green when young. Foliage-leaves 5–8 per branchlet. Foliage-leaf sheath pale hirsute, becoming glabrous. Foliage-leaf auricles small, rounded, blackish, long pale bristly when young. Foliage-leaf ligule short, blackish. Foliage-leaf blades (6) 12–15 (19.5) × (0.7) 1.0–1.9 cm, glabrous on both surfaces, linear to linear-lanceolate; base rounded to wedge-shaped; margins antrorsely scabrous; apex long acuminate; pseudopetiole short, 0.5–1 mm.

Comments: This clone is represented at Bambusetum Baan Sammi by only one plant, which has remained in its vegetative state. The plant grows slowly but well in normal garden soil. (Sep. 2017).

Specimen: BS-0530 [C2-R06] (living plant) = CS-3030, Krabi (กระบี่), 2010, received as "Dendro­calamus elegans, green"

Characteristics: Habit tight caespitose. Rhizome pachymorph, short, distance about 10 cm between old and new culm. Culms longer than 10 m, upright to slanted below, scandent above. Young shoots conical; sheath light green, thinly farinose, not hairy; culm-leaf blades spreading; emerge from June to July. Culm-internodes glabrous, smooth, thinly farinose and glossy when young, medium to dark green, brown when old, 27–38 (40) cm long, to 1.8 cm in diameter, very thick-walled, solid on basal culm, nearly solid on lower culm (walls 4.5 mm, lacuna 2 mm, internode diameter 1.1 cm at 2.2 m above ground; walls 4.5 mm, lacuna 1 mm, internode diameter 1.0 cm at 4.0 m above ground), moderately thick-walled on upper culm (walls 2 mm, lacuna 3 mm, internode diameter 0.7 cm). Culm-nodes slightly prominent; nodal line horizontal or slightly oblique; sheath scar a prominent corky ring, shiny black when young, dull brownish when old; supranodal line obscure; lowest node occasionally with aerial roots. Branch-buds solitary, subrotund to lancet arch-shaped, present from the basal node up; the internode is complanate above the bud for a few centimeters. Branches: Lower culm usually unbranched (for 3.5 m), mid-culm usually with a thick single branch on a node (occasionally a thick branch on 2 nodes on mid-culm, rarely on 3 nodes), elongating, 1/2 to 2/3 as thick as the main culm, widely arching and scandent, upper culm with several to numerous thin, short, subequal branches, scandent; branching intravaginal, occasionally infravaginal; branch nodes prominent. Culm-leaves deciduous, coriaceous. Culm-leaf sheath about 6 cm wide at the lower part, extending to 8–9 cm at the base, 20–22 cm long, about 1/2 as long as the internode, usually glabrous, but often with a narrow longitudinal patch in the middle of the sheath with appressed dense blackish hairs, light green and slightly farinose when young, light straw-colored and glabrous when dry, apex truncate, 1–1.5 cm wide, junction with the blade about 0.5 cm wide. Culm-leaf auricles inconspicuous, rim-like, 0.5–1 mm high, enduring blackish, extending to the sheath margin or minutely protruding, margin entire, without bristles. Culm-leaf ligule short, 1 mm high, enduring dark colored, margin slightly concave, finely toothed and with caducous, erect short pale bristles in the middle part, with very few and erect long pale bristles at both ends. Culm-leaf blade linear-lanceolate, reflexed. Foliage-leaves about 10–12 per branchlet. Foliage-leaf sheath glabrous. Foliage-leaf auricles inconspicuous or lacking, without bristles. Foliage-leaf ligule short, entire. Foliage-leaf blades variable in size, early developing leaves 18–28 × 1.5–3.5 cm, late developing leaves abundant and smaller, 9–23 × 1–1.8 cm, linear-lanceolate, glabrous on both surfaces; base wedge-shaped; margins antrorsely scabrous; apex long-acuminate; midrib somewhat prominent near the base on both surfaces; pseudopetiole short, 1–2 mm.

Comments:

(1) This clone is represented by only one plant at Bambusetum Baan Sammi; it grows well on normal garden soil, and has remained in its vegetative state (Aug. 2023).

(2) In the culm-leaf, ligule and rim-like auricles are attached or very closely adjacent at their edges, so it appears at first sight that the rather long and very slender bristles are attached to the end of the auricles. However, the bristles are actually extensions of the ligule. The auricles are entire and do not show any rudiments of bristles. In an early stage of development, when the culm-leaf is drying, the bristles fall off, and only the rudiments may remain attached to the ligule.