Gigantochloa auriculata s. Gamble

Gigantochloa auriculata s. Gamble (BS-0588): Young shoot and old culm with culm-leaves, young culms, auriculate foliage-leaf sheaths, habit (from left to right)

• • Characteristics: Habit tight caespitose. Rhizome pachymorph. Culms to 16 m long, straight, erect below, arching, apically down to the ground; unbranched on the ,basal, lower culm and mid-culm, but with short slender rudimentary branches on the basal and lower culm. Young shoots conical, with culm-leaf blades stiffly erect, light green, dark hairy; emerge in June. Culm-internodes 27–41 (50) cm long, mid-green, distally with a few loosely scattered short black rigid hairs when young, glabrous when old, with narrow yellowish stripes of various widths on the lower culm; diameter 5–8 cm; very thick-walled on the basal culm, sometimes solid, moderately thick-walled or thin-walled on the upper culm. Culm-nodes flat, glabrous; sheath scar prominent and elevated; supranodal line obscure or discernible, without a ridge. Branches several on the upper culm, central one dominant, rudimentary very thin short branches (with very small foliage-leaf blades) on the basal culm; branching intravaginal on the upper culm, extravaginal on the basal culm. Culm-leaves leathery, late deciduous on the upper culm, persistent and decaying on the basal, lower, and mid-culm. Culm-leaf sheaths half to two-thirds as long as the internode on the mid-culm, longer or nearly as long as the internode on the lower culm, light green when young, straw-colored when dry, with large patches of short, rigid, appressed dark-brownish hairs becoming blackish, these patches usually loosely arranged in two irregular lengthwise streaks from the base to the top, not reaching the left and right margin, and with an almost hair-free area in the middle part between the two lengthwise streaks; margins black ciliate; apex obtuse-triangular truncate, and with a triangular extension at the edges. Culm-leaf auricles rim-like, firm, rounded or oval-shaped towards the edge, entire, glossy and dark green when young; without bristles. Culm-leaf ligule low, about 2–3 mm, evenly high, subentire or irregularly denticulate. Culm-leaf blade stiffly erect, persistent or late caducous, triangular, about 6 cm wide and 23 cm tall, as long as the sheath, or longer as the sheath on the lower and mid-culm, adaxially scattered with short appressed blackish hairs, usually with a denser lengthwise streak of appressed blackish hairs in the middle; apex acuminate. Foliage-leaves (6) 9–11 (14) per branchlet. Foliage-leaf sheath glabrous, yellowish-green when young; margins eciliate. Foliage-leaf auricles small, rounded, entire, purplish when young; without bristles. Foliage-leaf ligule short, 1 mm, entire; outer ligule present. Foliage-leaf blades large, 30–40 × 6–8 cm, glabrous on both surfaces, mid-green above, light bluish-green beneath; margins antrorsely scaberulous; base rounded to cuneate; apex acuminate; midrib proximally prominent, whitish green beneath; pseudopetiole 5–9 mm long. Flowers and seeds are unknown.