GrassBase - The Online World Grass Flora


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

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

Aristida jorullensis

HABIT Annual; caespitose; clumped densely. Culms 10–60 cm long; 1–8 -noded. Culm-internodes solid; distally glabrous. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs; 0.1–0.2 mm long. Leaf-blades conduplicate, or involute; 4–20 cm long; 1–1.5 mm wide. Leaf-blade surface ribbed; scaberulous; rough adaxially; pilose; sparsely hairy; hairy adaxially.

INFLORESCENCE Inflorescence a panicle. Peduncle 7–15 cm long.

Panicle open; elliptic; 6–20 cm long. Primary panicle branches 1 -nate; 1–4 cm long; bearing spikelets almost to the base. Panicle axis pilose. Panicle branches pilose.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets cuneate; laterally compressed; 5–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5 mm long; pubescent; acute. Floret callus hairs 1 mm long.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume linear; 4.5–9 mm long; 0.9–1.1 length of upper glume; membranous; 1–3 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent, or distinct. Lower glume apex acute. Upper glume linear; 5–8.5 mm long; 1.2 length of adjacent fertile lemma; membranous; 1–3 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent, or distinct. Upper glume apex acute.

FLORETS Fertile lemma linear; laterally compressed; 4–7 mm long; coriaceous; without keel; 3 -veined. Lemma surface scabrous; rough above and in lines. Lemma margins convolute; covering most of palea. Lemma apex attenuate; awned; 1 -awned. Principal lemma awn flexuous; 10–16 mm long overall; with 10–16 mm long limb; without a column. Palea 1–1.5 mm long.

FLOWER Anthers 3; 1.1–1.7 mm long.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Aristideae. Fl Costaric 1993.

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