13.03 DASYPYRUM (Coss. & Durieu) T. Durand
Signe Frederiksen

Plants annual or perennial; shortly rhizomatous if perennial. Culms 20–100 cm. Sheaths open; auricles present, often inconspicuous; ligules 0.3–1 mm, membranous, truncate; blades 1–5 mm wide, flat, linear, central vein distinct on the abaxial side. Inflorescences terminal spikes, 4–12 cm long including the awns, 0.6–2 cm wide excluding the awns, compressed, dense, with 1 spikelet per node; rachis internodes flat, margins ciliate, hairs white; middle internodes 1–3 mm; disarticulation in the rachises, at the nodes beneath each spikelet. Spikelets 25–75 mm including the awns, 7–22 mm excluding the awns, more than 3 times the length of the rachis internodes, usually divergent, sometimes ascending, laterally compressed, with 2–4 florets, the lower 2 florets usually bisexual, the terminal florets sterile; rachilla internodes below the lower florets shorter than those below the terminal florets. Glumes equal, to 40 mm including the awns, to 8 mm excluding the awns, coriaceous, usually 5-veined, strongly 2-keeled, keels with 1–3 mm hairs, margins unequal, stiff, translucent, apices tapering into scabrous awns; bisexual lemmas 9–13 mm excluding the awns, lanceolate, keeled, usually 5-veined, apices acuminate, awned, awns to 60 mm; sterile lemmas smaller, awns to 10 mm; paleas narrowly lanceolate, membranous, 2-veined, 2-keeled; lodicules 2, free, membranous, ciliate or glabrous; anthers 3, 4–7 mm, yellow; ovaries pubescent; styles 2, free to the base. x = 7. Haplome V. Name from the Greek dasys, ‘shaggy’ or ‘hairy’, and pyros, ‘wheat’, an allusion to the hairy keels of the glumes.

Dasypyrum is a Mediterranean genus of two species; only one has been collected in the Flora region. The hairy, 2-keeled glumes make the genus easily distinguishable from other genera in the Triticeae.

SELECTED REFERENCE Frederiksen, S. 1991. Taxonomic studies in Dasypyrum (Poaceae). Nordic J. Bot. 11:135–142.

1. Dasypyrum villosum (L.) P. Candargy
Mosquitograss

Plants annual. Culms 20–100 cm, decumbent to geniculate, glabrous. Blades 1–5 mm wide, supple, light green. Spikes 4–12 cm long, 0.6–2 cm wide. Spikelets 7–22 mm excluding the awns. Glumes 9–40 mm including the awns, with tufts of hair on the keels, hairs 1.5–3 mm, white; bisexual lemmas 10–13 mm, glabrous proximally, sparsely pilose distally, with a tuft of stiff hairs below the awns, awns 15–60 mm, straight; sterile lemmas smaller, awns 7–10 mm; paleas to 14 mm; anthers 3, 4–7 mm. 2n = 14.

Dasypyrum villosum is native from southern Europe to Turkey, the Crimea, and the Caucasus. The only known North American record is a collection made in Philadelphia County, Pennsylvania, in 1877.

Dasypyrum breviaristatum (H. Lindb.) Fred. differs from D. villosum in being perennial and shortly rhizomatous, and in having stiff, dark green leaves, glume keels with hairs that are not in tufts, and awns to 15 mm long.