Stinkgrass

The caryopsis of this species is subglobose and reddish-brown in color, while those of the similar species, E. poaeoides are dark brown and broadly oblong.

Henrard (in Blumea 3:420.1940) has pointed out that Allioni’s description of Poa cilianensis mentions 3-4 branches per node of the inflorescence, and has suggested that he was in fact describing Poa trivialis Linn. However, the rest of the description, the figure (which shows only 1-2 branches per node) and the isotypes all contradict this view. Clayton (in Fl. Trop. E. Afr. 234. 1974) has accepted Lutati’s conclusion that Poa cilianensis is synonymous with the plant at one time known as Eragrostis major Host and his treatment is adopted here. Lutati, however, doubted his own conclusion and would not formally make the new combination although it is often ascribed to him. Eragrostis major, often applied to this species, is a new name dating from 1809 and is predated by Poa cilianensis (1785), the basis of Lutati’s combination. Sprague & Hubbard (in Kew Bull. 1933: 17. 1933) have listed the full synonymy.

This species is best recognised by the warty, crateriform glands on the leaf-margins and the rather stiff panicles of yellowish green or leaden grey spikelets. It does, however, intergrade with Eragrostis minor Host.

Stinkgrass, so called in North America from its disagreeable odour when fresh, is occasionally used as fodder.

Culm tufted. Blade linear-lanceolate, about 6 cm long by 4 mm wide, glandular along the midrib and margins; ligule a ring of hairs, about 0.5 mm long; sheath-mouth covered with tubercular hairs. Inflorescence an open panicle, about 11 cm long. Spikelets about 5.5 mm long by 2 mm wide, up to 12-flowered or more, linear-lanceolate; glumes chartaceous, boat-shaped, lanceolate in outline, 1-nerved, glandular along nerves; the lower about 1.2 mm long, slightly shorter than the upper; lemma chartaceous, broadly oblong, conspicuously 3-nerved, about 1.6 mm long; palea chartaceous, oblanceolate, rounded at the apex, 2-keeled, minutely ciliate on keels, about 1.2 mm long. Caryopsis about 0.5 mm long, oblong; embryo 1/2 the length of the caryopsis.

Annual. Culms rather robust, 30–90 cm tall, 3–5 mm in diam., erect or geniculate at base, 3–5-noded, a line of glands below each node. Leaf sheaths with glands along veins, along summit with tubercle hairs; ligules a line of hairs, ca. 0.5 mm; leaf blades flat, glabrous, 6–20 × 0.2–0.6 cm, along midvein and margin glandular. Panicle oblong or pyramidal, 5–20 cm; branch usually solitary, ascending; branchlet glandular. Spikelets dark green, gray-green or yellowish white, compressed, oblong or ovate-oblong, 5–20 × 2–3 mm, 10–40-flowered. Glumes subequal or lower glume slightly shorter, 1-veined, upper glume 1–3-veined, along middle vein glandular. Lemmas chartaceous, broadly ovate-oblong, conspicuously 3-veined, along middle vein glandular, lower lemma 2.2–2.8 mm. Palea persistent; oblanceolate, apex rounded, 1.2–1.6 mm, along keels ciliolate. Stamens 3; anthers ca. 0.5 mm. Caryopsis oblong, ca. 0.5 mm in diam. Fl. and fr. Jul–Oct. 2n = 40.

Loosely tufted annual; culms 10-90 cm high, erect or ascending. Leaf-blades flat, up to 15 cm long and 8 mm wide, mostly glabrous and usually with a row of warty glands along the margin. Panicle ovate, 4-30 cm long, fairly dense, contracted, stiffly branched, usually with glands on pedicels and branchlets. Spikelets 5-60-flowered, narrowly ovate to narrowly oblong, rarely linear, 3-20 min long, 2-4 mm wide, pallid yellowish green to leaden grey, breaking up from the base, the rhachilla often breaking off above the glumes before all the lemmas have fallen; glumes subequal, oval, boat-shaped, 1.5-2.2 mm long, 1-3-nerved, often glandular on the keel, acute; lemmas broadly ovate to subrotund, (1.7)2-2.8 mm long, chartaceous, often glandular on the keel, the lateral nerves distinct, emarginate or obtuse (occasionally bluntly acute) when flattened, usually obtuse in side-view; palea ± scabrid on the keels, persistent; anthers 3, 0.3 mm long. Caryopsis typically subglobose, 0.5(0.7) mm long, rarely oblong, dark reddish brown.

Widely distributed in the warmer regions of the world and can be used as a fodder grass.

Distribution: Pakistan (Sind, Baluchistan, Punjab, N.WF.P. & Kashmir); tropical and warm temperate regions of the Old World; introduced to the New World.

Fl. & Fr. Per.: May-October.

Waste places, fields, cultivated ground. Anhui, Beijing, Fujian, Guizhou, Hainan, Heilongjiang, Henan, Hubei, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Taiwan, Xinjiang, Yunnan, Zhejiang [tropical and subtropical regions of the world].

Poa cilianensis All., Fl. Pedem 2: 246. 1785.
Eragrostis major Host, Icon. Gram. Austr. 4: 14. pl. 24. ,1809.
Eragrostis megastachya (Koel.) Link, Hort. Berol. 1: 187. 1827.

Poa cilianensis Allioni, Fl. Pedem. 2: 246. 1785; Eragro-stis major Host; E. megastachya (Koeler) Link; Poa mega-stachya Koeler.