Eragrostis unioloides (Retz.) Nees ex Steud.

This species is very easily recognized by its extremely compressed large spikilets which are pinkish or sometimes pale in color.

This species is common throughout India but from our area it is known only from Kashmir. As there are no records from Iran or Afghanistan, it is possible that it does not occur in Pakistan. It should be looked for. It is called Eragrostis amabilis Wight & Arn. ex Nees in Fl. Brit. Ind. 7:317 and on many herbarium sheets.

Eragrostis unioloides is a hardy, but sporadic, species whose value as a fodder grass is unknown.

Annual. Culm solitary or tufted, erect or decumbent. Ligule wanting or very short. Inflorescence an oblong panicle, about 10 cm long. Spikelets 8-20-flowered, ovate-oblong, extremely compressed, purplish-red when mature, 4-7 mm long, the florets closely imbricate. Glumes acute, 1-nerved, the nerve prominent. Palea usually falling off together with the lemma, 2-keeled, very narrowly winged and minutely ciliate. Anthers 3, about 0.2 mm long. Caryopsis compressed, ellipsoidal, about 0.8 mm long.

Tufted annual or short-lived perennial; culms 10-80 cm high, erect or geniculately ascending, sometimes rooting from the lower nodes. Leaf-blades flat or inrolled, 2-20 cm long, up to 5.5 mm wide, subamplexicaul at the base, the apex subacute, glabrous or sparsely hairy towards the base. Panicle narrowly oblong to broadly ovate, 5-20 cm long, open or fairly densely contracted. Spikelets 11-80-flowered, ovoid to oblong, 3.5-16 mm long, 2.54 mm wide, the florets slightly overlapping and often diverging at nearly 90 degrees from the rhachilla, typically straw-coloured, tinged to deeply suffused with purple, breaking up from the base, the rhachilla persistent; glumes unequal, narrowly lanceolate in side-view, 1-nerved, the lower 1.3-1.7 mm long, the upper 1.7-1.9 mm long, subacute; lemmas broadly ovate to suborbicular when flattened, (1.5)1.8-2.2 mm long, punctulate, mucronulate, the nerves distinct; palea falling with the lemma, the keels scabrid; anthers 3, 0.2 mm long. Caryopsis obovoid or ellipsoid, laterally compressed, 0.6-0.8 mm long, orange-brown.

Annual or perennial. Culms erect or geniculate at base, 20–60 cm tall, 2–3 mm in diam., 3–5-noded. Leaf sheaths glabrous and smooth, long pilose along the summit; ligules membranous, ca. 0.8 mm; leaf blades sublanceolate, flat, 2–20 × 0.3–0.6 cm, adaxial surface long pilose, abaxial surface smooth, apex acuminate. Panicle open, oblong, 5–20 × 3–5 cm; branch solitary, glabrous in axils. Spikelets purplish red at maturity, oblong, 5–10 × 2–4 mm, with pedicel 0.2–1 cm, 10–20-flowered; florets closely imbricate; rachilla persistent, lower glume 1.5–2 mm, upper glume 2–2.5 mm. Lemmas broadly ovate, veins prominent, apex acute, the lower lemma ca. 2 mm. Palea slightly shorter than the lemma, 2-keeled, very narrowly winged and ciliolate, falling off together with its lemma at maturity. Stamens 2; anthers purple, 0.2–0.5 mm. Caryopsis compressed, ellipsoidal, ca. 0.8 mm. Fl. and fr. Aug–Oct.

Distributed in tropical Asia and Africa.

Distribution: Kashmir; Southeast Asia.

Africa, India, Nepal, S.E. Asia.

300-2200 m

Mountain slopes, grasslands, roadsides. Fujian, Hainan, Jiangxi, Taiwan, Yunnan [W Africa, tropical Asia].

Poa unioloides Retzius, Observ. Bot. 5: 19. 1788; Eragro-stis amabilis (Linnaeus) Wight & Arnold ex Nees; E. formo-sana Hayata; P. amabilis Linnaeus.

Poa unioloides Retz., Obs. Bot. 5: 19. 1789
Eragrostis formosana Hayata, Bot. Mag. Tokyo 21: 53 1907, Mat. Fl. Form. 408. 1911.

Annuals, Terrestrial, not a quatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves mostly cauline, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule a fringe of hairs, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or cu lm, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 3-7 florets, Spikelets with 8-40 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes distinctly unequal, Glumes shorter than adjacent lemma, Glumes 1 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea shorter than lemma, Palea 2 nerved or 2 keeled, Palea keels winged, scabrous, or c iliate, Stamens 2, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis isodiametric, trigonous or globose, broadest at base or beaked, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Tinh thảo đỏ (danh pháp khoa học: Eragrostis unioloides) là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (Retz.) Nees ex Steud. mô tả khoa học đầu tiên năm 1854.

牛虱草（学名：Eragrostis unioloides）是禾本科画眉草属的植物。分布在非洲热带、亚洲热带、台湾岛以及中国大陆的云南、福建、江西、华南各地等地，生长于海拔160米至1,300米的地区，常生于庭园、荒山、草地及路旁，目前尚未由人工引种栽培。