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.

Festuca petersonii

HABIT Perennial; caespitose. Butt sheaths papery; purple. Culms 10–18 cm long; 1 -noded. Culm-internodes yellow. Ligule an eciliate membrane; 0.5 mm long. Leaf-blades flexuous; filiform; conduplicate; 3–5 cm long; 0.5 mm wide. Leaf-blade venation with subepidermal sclerenchyma free from veins. Leaf-blade surface smooth; pubescent; hairy adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle, or comprising only a few spikelets; comprising 2–3 fertile spikelets.

Panicle open; linear; loose; 5–10 cm long; bearing few spikelets. Primary panicle branches indistinct the panicle almost racemose. Panicle axis glabrous.

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

FERTILE SPIKELETS Spikelets comprising 3 fertile florets; with diminished florets at the apex. Spikelets elliptic; laterally compressed; 8–11 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes scaberulous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2.5–3.5 mm long; 0.75 length of upper glume; chartaceous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface scabrous; rough above. Lower glume apex acute. Upper glume lanceolate; 3.5–4 mm long; 0.5 length of adjacent fertile lemma; chartaceous; without keels; 3 -veined. Upper glume surface scabrous; rough above. Upper glume margins scabrous. Upper glume apex acute.

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

FLOWER Lodicules 2. Anthers 3; 2.4 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION South America: western South America.

NOTES Poeae. Gr Bolivia 1997.

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