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.

Triniochloa gracilis

HABIT Perennial; caespitose. Basal innovations extravaginal. Culms erect, or geniculately ascending; 30–60 cm long; 0.5–0.8 mm diam. Leaf-sheaths tubular for much of their length; with 1 of their length closed; mostly shorter than adjacent culm internode; smooth, or retrorsely scabrous. Ligule an eciliate membrane; 2.5 mm long. Leaf-blades flat, or conduplicate, or involute; 10–15 cm long; 1.3–1.7 mm wide. Leaf-blade surface pilose; hairy adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle; comprising 7–38 fertile spikelets.

Panicle contracted; linear; 5–15 cm long; 0.3–0.5 cm wide. Primary panicle branches appressed; simple. Panicle branches smooth, or with occasional prickles.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 9–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus bearded.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate; 1.8–3 mm long; 1 length of upper glume; hyaline; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 1.8–3 mm long; 0.25–0.33 length of adjacent fertile lemma; hyaline; without keels; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma ovate; 9–12 mm long; coriaceous; without keel; 7 -veined. Lemma margins involute; interlocking with palea keels. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.66–0.75 way up back of lemma; geniculate; 12–16 mm long overall; with twisted column.

FLOWER Lodicules 2; united; fleshy; truncate. Anthers 3; 1.5–2.7 mm long.

FRUIT Caryopsis with adherent pericarp; 4.8–6 mm long. Hilum linear; 1 length of caryopsis.

DISTRIBUTION North America: Mexico.

NOTES Meliceae. Gomez-Sanchez 2005.

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