Bambusa sp. (TH: Satun)

Specimen: BS-0317 [BBG] (living plant), Satun, without precise locality, southern Thailand, wild, coll. by C. S., CS-3009, received as "ไผ่ยาว (phai yao)", 7 Nov. 2009.

Characteristics: Culm-internode mid-green, glabrous, initially thinly farinose (appearing bluish-green) and distally sparsely scattered with appressed dark hairs; walls moderately thick. Culm-node not prominent; nodal line with sheath scar not or slightly protruding; supranodal line obscure; with a whitish (farinose?) band above the supranodal line. Branches several, erect, unequal, the central one dominant; branching intravaginal. Culm-leaves deciduous (or persistent on the lower culm?), shorter than the internode. Culm-leaf sheath light straw-colored when dry, scattered with appressed light brown hairs becoming blackish with age; apex sinus-shaped truncate. Culm-leaf auricles rim-like, extending from the blade base towards the edges of the sheath apex, slightly increasing their height and ending in conspicuous long-ovate lobes, dark colored when young. Culm-leaf ligule low, subentire or denticulate(?). Culm-leaf blade caducous, lanceolate, patent to reflexed, mid-green, light straw-colored, and twisted when dry. Foliage-leaf sheath green, with a reddish tint towards the apex when young, sparsely scattered with short dark (initially whitish?) hairs, apex with a rounded extension. Foliage-leaf auricles conspicuous glabrous lobes, erect, somewhat protruding, initially light green, without bristles. Foliage-leaf ligule inconspicuous, outer ligule present. Foliage-leaf blade base rounded to attenuate; pseudopetiole long.

Comments:

(1) The Thai name, ไผ่ยาว (phai yao), might refer to the long internodes of this bamboo.

(2) The identification of BS-0317 remains unresolved. It could be a species of the genus Gigantochloa or Bambusa. Since the plant has left Bambusetum Baan Sammi, it cannot be re-examined.

(3) One specimen with largely similar characteristics is BS-0477, provisionally classified as a Gigantochloa species. Both have an apical extension of the foliage-leaf sheaths, but this extension is horn-like in BS-0477, not rounded.