GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Aulonemia soderstromii

HABIT Perennial. Rhizomes short; pachymorph (amphipodial, rooting from decumbent culm). Culms erect, or decumbent, or scandent; 150–800 cm long; 3–10 mm diam.; woody. Culm-internodes terete; solid; 12–34.5 cm long; distally glabrous, or pubescent. Culm-nodes with distinct supra-nodal ridge. Lateral branches suffrutescent. Bud complement 1. Branch complement one; solitary. Culm-sheaths 3.5–9.5 cm long; green, or purple; glabrous; setose on shoulders; shoulders with 13–35 mm long hairs. Culm-sheath ligule 0.4–0.8 mm high; ciliolate. Culm-sheath blade lanceolate, or narrowly ovate; constricted at base; reflexed; 5.2–11.3 cm long; 12–32 mm wide; glabrous on surface, or pubescent. Leaf-sheaths 4–8 cm long; glabrous on surface, or pilose; outer margin hairy. Leaf-sheath oral hairs bearded; spreading and deciduous; 8–25 mm long. Leaf-sheath auricles absent. Ligule a ciliolate membrane; 0.3–0.6 mm long. Collar with external ligule. Leaf-blade base asymmetrical; with a brief petiole-like connection to sheath; petiole 0.3–0.5 cm long; petiole glabrous, or pubescent. Leaf-blades lanceolate, or ovate; (7.5–)11–23 cm long; 20–45 mm wide; chartaceous. Leaf-blade venation without cross veins. Leaf-blade surface glabrous, or pubescent; hairy on both sides. Leaf-blade margins scabrous. Leaf-blade apex acuminate, or attenuate.

INFLORESCENCE Inflorescence a panicle. Peduncle glabrous.

Panicle open; oblong, or pyramidal; 8–19.2 cm long; 6–10.5 cm wide.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2–13 mm long; glabrous.

FERTILE SPIKELETS Spikelets comprising 2–7 fertile florets; without rhachilla extension, or with diminished florets at the apex. Spikelets linear, or lanceolate; laterally compressed; compressed slightly; 12–31 mm long; 2–6 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 4.2–4.9 mm long; glabrous.

GLUMES Glumes two; 2 empty glumes; persistent; dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 4.8–6 mm long; membranous; 5–6 -veined. Lower glume surface glabrous, or puberulous. Lower glume apex acute. Upper glume lanceolate; 6.7–7.5 mm long; membranous; 7–9 -veined. Upper glume surface glabrous, or puberulous. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 9–10.5 mm long; chartaceous; without keel; 8–9 -veined. Lemma surface scabrous; rough on veins; glabrous, or puberulous. Lemma margins scabrous. Lemma apex acute. Palea 8.5–10.2 mm long; 8–11 -veined. Palea keels scabrous; adorned above. Palea surface glabrous, or puberulous; hairy on back. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; ciliate. Anthers 3; 4 mm long; pallid, or yellow. Ovary glabrous.

DISTRIBUTION South America: Brazil.

NOTES Bambuseae. Vianna, Filg. & Judz. 2014.

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