Chloothamnus elatus

Specimen: BS-0245 [S3] (living plants), received as "Nastus elatus" from cultivated stock from the USA in 2009.

Characteristics: Habit tight caespitose. Rhizome pachymorph, short-necked. Culms straight, over 10 m long [ultimate size not yet known], erect below, bending above, tips drooping. Young shoots light green, glabrous, covered with a white mealy deposit, appearing bluish; culm-leaf blades green, patent; emerge from May/June to September. Culm-internodes terete, 25–32 cm long on mid-culm, bright green when young, glabrous, initially farinose, dull mid-green with a bluish tint and smooth when old; diameter 5 cm [ultimate diameter not yet known]; thin-walled, easily splitting, lacuna with white pith on the basal culm, the pith not easily removable when old, lacuna without pith on the lower, mid, and upper culm (5th internode 85 cm above the ground, diameter 1.9 cm, wall thickness 2–2.5 mm). Culm-nodes glabrous, flat; nodal line horizontal; sheath scar marginally protruding; supranodal line clearly discernible; with a white ring below sheath scar; aerial roots none. Branch-buds solitary, small, margins initially densely pale ciliate, the first 2–3 (4) lowest nodes without a bud. Branches many, subequal, thin, 1–2 mm in diameter, from the mid-culm up; branching extra­vaginal, infra­vaginal, and intra­vaginal; branching initiates from the mid-culm upwards; rebranching. Culm-leaves deciduous. Culm-leaf sheaths 8–12 cm wide at the base, 14–16 cm long, half as long as the internode, or a little longer, rigid, light green to greenish-yellow, and copiously covered with a white mealy deposit when young, yellowish green, smooth and almost glossy with age, dull yellowish straw-colored with dark spots when dry; margins eciliate; apex rounded. Culm-leaf auricles inconspicuous or none, without bristles. Culm-leaf ligule inconspicuous, ca. 1 mm high, entire, eciliate. Culm-leaf blades rigid, caducous, deflexed to reflexed, linear to broad-linear to lanceolate, 1.5–2 cm wide at the junction with the sheath, 6–10 cm long, green when young, straw-colored when dry. Foliage-leaves (7) 11–15 per branchlet. Foliage-leaf sheaths green, glabrous. Foliage-leaf auricles inconspicuous or none, without bristles. Foliage-leaf ligule very short, entire, eciliate. Foliage-leaf blades soft, (11) 17 (19) × (0.8) 1.1 (1.3) cm, linear, mid-green to light green, glabrous above, finely pubescent beneath; base rounded to wedge-shaped; apex long-acuminate; margins antrorsely scaberulous; midrib not prominent; pseudopetiole short, 0.5–1 mm long.