Festuca tristis Krylov & Ivanitzk Animad. Syst. Herb. Univ. Tomsk 1:1. 1928.
HEI SHUI YANG MAO.
Subg. Leucopoa (Griseb.) Tzvel., sect. Breviaristatae Krivot.
Vegetative morphology. Plants stiffly erect. Plants loosely tufted, or turf forming, or densely tufted. Plants clumped loosely. Plants with non-flowering shoots more common than flowering shoots. Plants with leaves mostly basal. Plants with tillering leaves 1/4 to 1/3 the length of the culms, or over half the length of the culms. Plants with bases not purplish. Plants with shoots intravaginal. Culms 30–50 cm tall. Culms 1.1–1.4 mm wide. Culms strict, erect. Culms internodes glabrous. Culms internodes ridged or striped. Butt sheaths present. Butt sheaths withering. Butt sheaths with compacted dead sheaths. Sheaths longer than the internode. Sheaths glabrous. Sheaths open more than half their length. Sheaths conspicuous at the base of the plant, persisting for more than 1 year. Sheaths remaining entire, not conspicuously splitting between the veins. Auricles erect swellings. Auricular cilia absent. Ligules 0.1–0.3 mm long. Ligules membranous. Ligules margins ciliate. Ligules apices erose, or lacerate. Leaf blades more or less lax. Leaf blades filiform. Leaf blades flat, or involute (usually). Leaf blades 4–25 cm long. Leaf blades adaxial surfaces with trichomes. Leaf blades adaxial surfaces scabrous. Leaf blades abaxial surfaces glabrous. Flag leaves blades 3–5 cm long. Flag leaves blades distinctly shorter than the sheath (5/13). Leaf blades 0.5–0.8 mm wide. Leaf blades 0.8 mm deep. Veins 5–7. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma well developed. Abaxial sclerenchyma in narrow or discrete strands. Ribs (3–)5.
Floral morphology. Inflorescences narrowly lanceolate, or lanceolate. Inflorescences loosely open. Inflorescences not nodding. Inflorescences 7–13 cm long. Inflorescences branches 2–5 cm long. Inflorescences lowest internodes 1.5–3 cm long. Inflorescences branches at the lowest nodes 1, or 2. Inflorescences branches flexible, or capillary. Inflorescences branches spreading after anthesis. 4–5 fertile spikelets on the longest branches. Inflorescences branches rounded in cross section. Inflorescences branches scabrous on the angles, or glabrous. Inflorescences branches vestiture sparse. Pedicels 5–10 mm long. Spikelets loosely scattered in an open panicle with slender branches, or aggregated towards the ends of the branches (but only a few spikelets). Spikelets 8–12 mm long. Spikelets (2.5–)5–7 mm wide. Spikelets purplish, or brown (shiny due to wide transparent margins on lemmas), or brown. Florets 3–4. Glumes membranous. Glumes glabrous. Glumes margins not ciliate. Glumes margins broadly membranous. Glumes apices accuminate. First glume narrowly lanceolate. First glume 4.5–5.5 mm long. First glume 1 nerved. First glume 0.7–0.8 as long as second glume. Second glume lanceolate. Second glume 5.7–6.7 mm long. Second glume 3 nerved. Second glume shorter than first lemma. Second glume 0.4–0.6 as long as the spikelets. Rachilla internodes 1.2–1.5 mm long. Rachilla internodes antrorsely scabrous. Rachilla internodes flattened, or cylindrical. Lemmas 6–7 mm long. Lemmas lanceolate. Lemmas membranous. Lemmas rounded on the back, or weakly keeled. Lemmas veins 5 (prominent). Lemmas with distinct veins in dorsal view. Lemmas with trichomes. Lemmas punctiform, or scabrous. Lemmas trichomes over the entire surface. Lemmas margins smooth. Lemmas upper margins narrowly membranous. Lemmas apices entire. Lemmas apices accuminate. Lemmas apices awns present. Lemmas apices awns (0.3–)1–2 mm long. Lemmas apices awns much shorter than the lemmas. Paleas 5.7–7.7 mm long. Paleas 0.7–1 mm apart. Paleas equal or subequal to the lemmas. Paleas keels scaberulous. Paleas inter-keel regions punctiform. Lodicules 1 mm long. Anthers 2.9–3.6 mm long. Ovary apices hairy. Ovary hairs moderate. Fruits 3.8–4.3 mm long.
Ecology. Flowering time Jul-Sep. On alpine meadows; 2800–3800 m. Distribution. Northwestern China: Xinjiang.
Notes. Classification following Tzvelev (1976).
Illustrations. • Leaf cross section 1. Leaf blade 0.5–0.8 mm wide, 0.8 mm deep; veins 7. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma well developed, in narrow or discrete strands; ribs 5. Drawn by Xiang Chen, from PE: Qing Renchang 1037, with permission. • Leaf cross section 2. Leaf blade 0.5–0.8 mm wide, 0.8 mm deep; veins 5 Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma well developed, in narrow or discrete strands; ribs 5. • Distribution map.
Cite this publication as: ‘Xiang Chen, S.G. Aiken, and M.J. Dallwitz (2002 onwards). Festuca of China: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 4th February 2003. http://www.cdelta.ibcas.ac.cn’.
