Anthoxanthum odoratum L.

A new introduced grass at 2,000 m alt. in central Taiwan

Sweet Vernal-grass is a polymorphic species, varying considerably in size, leafiness and hairiness. At one time it was included in seed-mixtures for pasturage or hay on account of its fragrant smell, but it is not very palatable to stock and has a high proportion of stem to leaf.

Perennials, withot conspicuous rhizome. Culms tufed, erect slender, 20-60 cm tall, 1 mm in diameter. Leaves radical and caline. Blades short-linear, 2-13 cm long, 2-4 mm wide, flat, soft, generally sparsely pilose on both surfaces; ligules 3.5 mm long, white hyaline; sheath sparsely pilose. Panicle erect, contrated and spike-like, lanceolate, 2-4.5 cm long, 5-10 mm wide, contiguous or somewhat intrrupted with vestige branches below, ligt green and eventually yellow-brown; branches short, scabrous, sparsely pilose. Spikelets on pubescent short pedicel, lanceolate, 7-8 mm long, compressed, shiny, 3-flowered, the lower tw sterile, and the uppermost one perfect and fertile; glumes unequal, strongly folded with acute keel, the keel scabrous above, sometime hairy on keel; the lower glume narrowly ovate, hyaline, 3.5-4 mm long, 1-nerved; the upper glume widely lanceolate, dotted, 7-8 mm long, 3-nerved. Both sterile lemmas narrowly oblong, 3 mm long, brownish, pubescent with brown hairs except at bilobed apex; the lower lemma with a straight awn arising at 1/4 from the base. Fertile lemma obovate, 2 mm long, glabrous, smooth, faintly 3-nerved. Palea lanceolate oblong, 1-nerved. Anthers 2, each 3.5-4 mm long.

Plant loosely tufted, sometimes rhizomatous. Culms 15–60(–100) cm tall, 1–3-noded. Leaf sheaths glabrous or loosely pilose, mouth glabrous or bearded; leaf blades flat, up to 12 cm, 2–7 mm wide, glabrous or loosely pilose, smooth or scabrid, apex acuminate; ligule 1–3 mm, obtuse. Panicle dense, spikelike, lanceolate to narrowly oblong in outline, 2–7(–10) × 0.4–1 cm; branches short; pedicels pubescent or glabrous. Spikelets lanceolate, 6–9 mm; glumes unequal, pubescent or punctiform-scabrid, margins sometimes ciliate, lower glume ca. 1/2 length of upper glume, 1-veined, upper glume subequal to spikelet, 3-veined; lower florets sterile, composed only of lemmas, 2.5–3.5 mm, pilose on back, apex 2-lobed, lobes short, obtuse; first lemma awned from near middle, awn straight, 2–4 mm; second lemma awned near base, awn geniculate, 7–9 mm; bisexual floret 2–3 mm, smooth, shiny; palea 1-veined; anthers 3–4.5 mm. Fl. and fr. May–Aug.

Tufted perennial. Culms 10-50 (-100) cm high, erect. Leaf-blades 1-12 (-30) cm long, 1.5-5(-9) mm wide, glabrous to sparsely hairy, finely pointed at the tip; ligule 1-5 mm long. Panicle very dense to somewhat loose, ovate to narrowly oblong, 1-9 (-12) cm long, 6-15 mm wide, green or purplish. Spikelets lanceolate, the upper awn protruding; glumes thinly membranous, loosely to sparingly hairy; lower glume ovate, 3-5 mm long, 1-nerved, mucronate; upper glume ovate to elliptic, 6-10 mm long, 3-nerved, mucronate; sterile lemmas 3-3.5 mm long, obscurely bibbed, the awn of the upper 6-9 mm long; fertile lemma 2 mm long; anthers 3-4.5 mm long.

Native to Europe and Siberia

Jiangxi, Taiwan (introduced), Xinjiang, NE China [Japan, Korea, Mongolia, Russia; Europe].

Distribution: Pakistan (Baluchistan & N.W.F.P.); widespread in Europe and temper-ate Asia; introduced to North America.

Meadows, alpine steppe; 1400–2900 m.