About Stipa tirsa Steven
Stipa tirsa Steven is a perennial, tuft-forming grass that grows culms 40 to 100 cm tall. Its leaf sheaths are glabrous, ligules are short at 0.2–0.5 mm, and leaf blades are filiform, involute, 1–2 mm wide, puberulous and hairy on the underside, with attenuate tips. Its inflorescence is a contracted, linear panicle that is subtended at the base by a leaf. Spikelets are solitary, pedicelled, and 50–65 mm long, each bearing one fertile floret and disarticulating when mature. Glumes are lanceolate, acuminate, membranous, and longer than the florets, measuring 50–65 mm in length. The fertile lemma is elliptic, 18–20 mm long, pubescent in lines, convolute around the inner palea, and ends in a single awn. The awn is bigeniculate, 350–500 mm long, with a twisted column and a plumose limb. The inner palea is equal in length to the lemma and has 2 veins. Flowers have three small lodicules, three smooth-tipped anthers, and two stigmas, with a glabrous ovary. The fruit is a caryopsis (grain) with an adherent pericarp and a linear narrow hilum. According to Plants of the World Online, Stipa tirsa is native to parts of Europe and Asia, ranging from the Iberian Peninsula east to Siberia.
