Stipa tirsa is a species of perennial grass native to Europe and temperate Asia. Culms are 40–100 cm long; leaf blades are filiform, involute, and 1–2 mm wide.
Description S. tirsa is a perennial, tuft-forming grass with culms 40–100 cm tall. Leaf-sheaths are glabrous, ligules short (0.2–0.5 mm), and blades filiform, involute, 1–2 mm wide, puberulous and hairy beneath, with attenuate tips. The inflorescence is a contracted, linear panicle subtended at the base by a leaf. Spikelets are solitary, pedicelled, and 50–65 mm long, each with a single fertile floret and disarticulating at maturity. Glumes are lance-shaped (lanceolate), pointed (acuminate), membranous, and longer than the florets (50–65 mm). The fertile lemma is elliptic, 18–20 mm long, pubescent in lines, convolute around the inner bract (palea), and terminates in a single awn. The awn is bent twice (bigeniculate), 350–500 mm long, with a twisted column and feathery (plumose) limb. The inner bract equals the lemma in length, 2-veined. Flowers have three small scales (lodicules), three smooth-tipped anthers, and two stigmas; the ovary is glabrous. The fruit is a grain (caryopsis) with adherent outer layer (pericarp) and a linear narrow scar (hilum).
Distribution and habitat According to Plants of the World Online, Stipa tirsa is native to parts of Europe and Asia, occurring from the Iberian Peninsula eastwards to Siberia.
Region Country/Areas Balkans Albania; Bulgaria; Northwest Balkan Peninsula Central Europe Austria; Czechia–Slovakia; Germany; Hungary Southern Europe France; Italy; Romania; Spain Eastern Europe Ukraine; Krym (Crimea); European Russia (Central, East, South) Caucasus North Caucasus; Transcaucasus Western Asia Türkiye Central Asia Kazakhstan; West Siberia
Synonyms Stipa stenophylla (Czern. ex Lindem.) Trautv.
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