Arthrostylidium auriculatum

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms scandent; pendulous at the tip; 200–400 cm long; 2–3 mm diam.; woody. Culm-internodes terete; with small lumen; 30–49 cm long; yellow, or light green; distally glabrous. Lateral branches dendroid; intravaginal. Bud complement 1. Branch complement several; in a clump; subtended by a bare patch above the node; with 1 branch dominant; thinner than stem. Culm-sheaths persistent; 4–8 cm long; pubescent; hairy on margins. Leaves 4–6 per branch. Leaf-sheaths pubescent. Leaf-sheath oral hairs setose; 5–8 mm long; dark. Leaf-sheath auricles erect; 1–2.5 mm long. Ligule a ciliolate membrane; 0.5 mm long; pubescent on abaxial surface. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.3–0.5 cm long; petiole glabrous. Leaf-blades lanceolate; 5–16 cm long; 12–25 mm wide. Leaf-blade venation with 14–15 secondary veins. Leaf-blade surface pubescent; hairy abaxially. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; straight; bilateral; 15–30 cm long; bearing 17–19 fertile spikelets on each. Rhachis glabrous on surface, or puberulous on surface. Spikelet packing broadside to rhachis; distant. Rhachis internodes 3–20 mm long.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 13–22 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes flattened; 3–5 mm long.

GLUMES Glumes several; 3 empty glumes; persistent; similar; shorter than spikelet. Lower glume elliptic; 4.5–6 mm long; chartaceous; without keels. Lower glume surface puberulous. Lower glume margins ciliate. Lower glume apex acute. Upper glume elliptic; 4.5–6 mm long; without keels. Upper glume surface puberulous. Upper glume margins ciliate. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 6–7.5 mm long; 2–2.5 mm wide; chartaceous; without keel; 7–9 -veined. Lemma surface rugulose; without grooves; puberulous. Lemma margins ciliate. Lemma apex acute; mucronate. Palea 6–6.5 mm long. Apical sterile florets 1 in number; rudimentary.

FLOWER Lodicules 3. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; 5.5 mm long. Embryo 0.15 length of caryopsis. Hilum linear; 1 length of caryopsis.

DISTRIBUTION South America: western South America.

NOTES Bambuseae. Lord & Clarke 2001.

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