Arthrostylidium schomburgkii

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms leaning; 1000–1500 cm long; 15–35 mm diam.; woody. Culm-internodes unequal, the lower longer; terete; hollow; 300–500 cm long (lowest), or 35–45 cm long; light green; smooth; distally glabrous. Lateral branches dendroid. Bud complement 1. Branch complement several; in a clump; subtended by a bare patch above the node; with 1 branch dominant; thinner than stem. Leaves 4–7 per branch. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs scanty; 5–15 mm long. Ligule a ciliolate membrane; 0.2 mm long. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.2–0.3 cm long. Leaf-blades lanceolate; 17–23 cm long; 9–12 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes. Peduncle 10–15 cm long.

Racemes 1; single; bilateral; 15–25 cm long; bearing 5–8 fertile spikelets on each. Rhachis semiterete; glabrous on surface. Spikelet packing broadside to rhachis; distant.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 4–15 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 40–70 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes elongated between glumes. Rhachilla elongation 2.5–3 mm long. Rhachilla internodes 3–5 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 6–16 mm long; 0.6–1 length of upper glume; chartaceous; without keels; 1–5 -veined. Lower glume lateral veins absent, or obscure. Lower glume apex acute. Upper glume lanceolate; 10–16 mm long; 0.75 length of adjacent fertile lemma; without keels; 3–5 -veined. Upper glume apex acute; awned; 1 -awned. Upper glume awn 2–4 mm long.

FLORETS Basal sterile florets barren; with palea; persisting on inflorescence. Lemma of lower sterile floret present; similar to fertile lemma. Fertile lemma elliptic, or ovate; 13–18 mm long; 3–4 mm wide; chartaceous; without keel; 7 -veined. Lemma lateral veins prominent. Lemma apex acute; awned; 1 -awned. Principal lemma awn 4–7 mm long overall. Palea elliptic; 8–9 mm long. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; lanceolate; 3–4 mm long; glabrous. Anthers 3; 6.5 mm long; yellow. Filaments 0.5 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: northern South America.

NOTES Bambuseae. Jud. & Clarke 2001.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.