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.

Festuca tolucensis

HABIT Perennial; caespitose; clumped densely. Cataphylls inconspicuous. Rhizomes absent. Basal innovations intravaginal. Culms erect; of moderate stature; straight; 50–100 cm long; 1.5–2 mm diam.; without nodal roots. Culm-internodes terete. Culm-nodes constricted; brown; without exudate; glabrous. Lateral branches lacking. Leaves mostly basal; 0–1 per branch. Leaf-sheaths tight; unthickened at base; open for most of their length; without keel; striately veined; scaberulous; glabrous on surface. Ligule an eciliate membrane; 1–2.5 mm long; membranous; white; entire; acute. Leaf-blade base symmetrical. Leaf-blades straight; filiform; conduplicate; elliptic in section; 12–25 cm long; 1–1.5 mm wide; coriaceous; stiff, or firm; yellowish green, or dark green. Leaf-blade midrib indistinct. Leaf-blade venation indistinct; with 3–4 inner ridges; with subepidermal sclerenchyma strands similar in size; with subepidermal sclerenchyma attached to veins below; with continuous uniform subepidermal sclerenchyma layer on the underside. Leaf-blade surface ribbed; scabrous; puberulous; moderately hairy; hairy adaxially. Leaf-blade margins scabrous; glabrous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle; with 1 peduncles per sheath. Peduncle terete; 15–30 cm long; eglandular; glabrous.

Panicle open; lanceolate, or ovate; continuous, or interrupted; dense; straight; 11–20 cm long; bearing few spikelets. Primary panicle branches ascending, or spreading; 1–2 -nate; moderately divided; naked below, or bearing spikelets almost to the base. Panicle branches straight, or arcuate.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–4(–6) fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 8–12(–15) mm long; breaking up at maturity; disarticulating below each fertile floret. Spikelet callus glabrous. Rhachilla internodes scaberulous. Floret callus glabrous.

GLUMES Glumes persistent; similar; subequal in width; shorter than spikelet. Lower glume lanceolate; 6–8.5 mm long; 0.75–0.85 length of upper glume; chartaceous; mid-green, or light brown; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume oblong; 6–7.4 mm long; 0.9–1 length of adjacent fertile lemma; chartaceous; dark green, or light brown; without keels; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; symmetrical; 6–8 mm long; chartaceous; dark green, or light brown; without keel; 5 -veined. Lemma lateral veins with distinct primaries but obscure intermediates. Lemma surface scaberulous; glabrous, or puberulous. Lemma apex acuminate; muticous, or awned; 1 -awned. Principal lemma awn stiff; 0–1 mm long overall. Palea 0.9 length of lemma; 2 -veined. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2. Anthers 3; 2.8–3.4 mm long; yellow. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, northern South America, and western South America.

NOTES Poeae. Stancik 2005.

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