Arthrostylidium scandens

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms arching, or leaning, or scandent; slender; 500–800 cm long; 5–9 mm diam.; woody; rooting from lower nodes. Culm-internodes terete; with small lumen; smooth; distally glabrous. Culm-nodes brown, or purple. Lateral branches dendroid; intravaginal. Bud complement 1. Branch complement two, or three; in a clump; subtended by a bare patch above the node; with subequal branches. Culm-sheaths deciduous; distinctly mottled with last colour; glabrous on margins, or hairy on margins; without auricles; glabrous on shoulders. Culm-sheath ligule 0.2–0.3 mm high; ciliolate. Culm-sheath blade lanceolate; deciduous; 7–11 cm long. Leaves 5–9 per branch. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs lacking, or setose; 6–10 mm long; pale, or dark. Leaf-sheath auricles erect. Ligule an eciliate membrane; 3–5 mm long; membranous; brown. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.4–0.6 cm long; petiole glabrous. Leaf-blades deciduous at the ligule; lanceolate; 10–23 cm long; 15–45 mm wide. Leaf-blade midrib indistinct. Leaf-blade surface glabrous, or puberulous; hairy abaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 1; single; straight; bilateral; 10–25 cm long; bearing 7–12 fertile spikelets on each. Rhachis glabrous on surface. Spikelet packing broadside to rhachis; lax.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1–3 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 28–40 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes flattened; clavate; 4–7 mm long; eventually visible between lemmas.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume elliptic; 4–5 mm long; chartaceous; without keels; 1–5 -veined. Lower glume lateral veins absent, or distinct. Lower glume apex acute. Upper glume lanceolate; 6–7 mm long; 1-keeled; keeled above; 5–7 -veined. Upper glume apex acute; mucronate.

FLORETS Basal sterile florets barren; with palea; persisting on inflorescence. Lemma of lower sterile floret similar to fertile lemma. Fertile lemma lanceolate, or ovate; 9–11 mm long; chartaceous; without keel; 7–9 -veined. Lemma apex acute; mucronate. Palea 1 length of lemma. Palea surface puberulous; hairy on back. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3. Anthers 3. Stigmas 2. Ovary umbonate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: northern South America.

NOTES Bambuseae. Fl Guiana 1995.

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