Festuca amplissima

HABIT Perennial; culms solitary, or cushion forming; clumped loosely. Cataphylls inconspicuous, or evident. Rhizomes short; fleshy; not obviously scaly. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Basal innovations extravaginal. Culms erect; robust; straight, or curved; 110–150 cm long; 2–3 mm diam.; without nodal roots. Culm-internodes terete; smooth, or scaberulous. Culm-nodes constricted; brown; without exudate; glabrous. Lateral branches lacking. Leaves basal and cauline; 3–5 per branch. Leaf-sheaths tight; unthickened at base; open for most of their length; without keel; striately veined; antrorsely scabrous; glabrous on surface. Ligule an eciliate membrane; 0.5 mm long; scarious; white, or brown; entire. Leaf-blade base symmetrical. Leaf-blades erect; straight, or flexuous; linear; linear in section; 20–50 cm long; 7–8 mm wide; flaccid; dark green. Leaf-blade midrib indistinct. Leaf-blade venation distinct; with subepidermal sclerenchyma strands similar in size; with subepidermal sclerenchyma attached to veins above and below; without layer of subepidermal sclerenchyma masking vein striation. Leaf-blade surface scabrous; rough abaxially; puberulous; sparsely hairy; hairy adaxially. Leaf-blade margins scabrous; glabrous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle; with 1 peduncles per sheath. Peduncle straight, or flexuous; terete; 20–40 cm long; eglandular; antrorsely scabrous above; glabrous.

Panicle open; elliptic, or pyramidal; continuous; loose; straight; 30–40 cm long; 25–40 cm wide. Primary panicle branches ascending; 5 -nate; profusely divided; 10–12 cm long; naked below. Panicle branches flexible; straight, or arcuate; scaberulous.

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

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 12–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Spikelet callus pilose. Rhachilla internodes scaberulous. Floret callus sparsely hairy.

GLUMES Glumes persistent; similar; subequal in width; shorter than spikelet. Lower glume linear; 4.5–6 mm long; 0.6–0.7 length of upper glume; chartaceous; mid-green; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 4.8–6 mm long; 0.8–0.9 length of adjacent fertile lemma; chartaceous; mid-green; without keels; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; symmetrical; 5.5–7 mm long; chartaceous; mid-green; without keel; 5 -veined. Lemma surface scabrous. Lemma apex acuminate; muticous. Palea 1 length of lemma; 2 -veined. Palea keels scabrous. Palea surface scabrous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2. Anthers 3; 2–2.8 mm long; purple. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, or northern South America.

NOTES Poeae. Stancik 2005.

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