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.

Aegilops triuncialis

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 15–45 cm long. Leaf-sheath oral hairs ciliate. Leaf-sheath auricles falcate. Ligule an eciliate membrane. Leaf-blades flat, or involute; 5–10 cm long; 1–2 mm wide. Leaf-blade surface glabrous, or pilose.

INFLORESCENCE Inflorescence composed of racemes; not deciduous as a whole, or deciduous as a whole.

Racemes 1; single; lanceolate; bilateral; 3–6 cm long; bearing few fertile spikelets; bearing (3–)4–6 fertile spikelets on each. Rhachis tough, or fragile at the nodes. Spikelet packing broadside to rhachis. Rhachis internodes oblong; when fragile falling with spikelet alongside.

Spikelets solitary. Fertile spikelets sessile.

STERILE SPIKELETS Basal sterile spikelets rudimentary; 2–3 in number.

FERTILE SPIKELETS Spikelets comprising 4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 7–10 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; shorter than spikelet. Lower glume oblong; 7–10 mm long; 1 length of upper glume; coriaceous; without keels; 7–9 -veined. Lower glume lateral veins unequally thickened; ribbed. Lower glume surface smooth, or scabrous. Lower glume apex dentate; 3 -fid; awned; 2–3 -awned. Lower glume awn 10–60 mm long. Upper glume oblong; 7–10 mm long; 0.9 length of adjacent fertile lemma; coriaceous; without keels; 7–9 -veined. Upper glume lateral veins unequally thickened; ribbed; parallel at apex. Upper glume surface smooth, or scabrous. Upper glume apex dentate; 3 -fid; awned; 2–3 -awned. Upper glume awn 10–60 mm long.

FLORETS Fertile lemma oblong; 7–10 mm long; coriaceous; without keel; 5 -veined. Lemma apex dentate; 2 -fid; awned only on distal spikelets; 3 -awned. Principal lemma awn 5–6 mm long overall. Palea 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex. Disseminule comprising a rhachis internode, or inflorescence.

DISTRIBUTION Europe: southwestern, southeastern, and eastern. Africa: north. Asia-temperate: Soviet Middle Asia, Caucasus, western Asia, and Arabia. Asia-tropical: India. North America: northeast USA and southwest USA.

NOTES Triticeae. Fl Turk 1993.

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