S. carinata C.A. Mey. in Eichw., Pl. nov. 2: 36. 1835 non Spreng. 1825; Boiss., Fl. Or. 4: 955. 1879 (p.p.); Iljin in Fl. SSSR 6: 257. 1936; Kitamura, Fl. Afg. 104. 1960; S. sclerantha C.A. Mey. var. carinata (C.A. Mey.) Minkw. in Fedtsch., Perec. Rast.Turkest. 6: 243; 1916; S. leptoclada Gand. in Bull. Soc. Bot. France 60: 421. 1913; Pratov in Consp. Fl. As. Med. 3: 94. 1968; Freitag in Ali & Ghaffar, Pl. Life S. Asia 85. 1991; Botsch. in Novosti Sist. Vyssh. Rast. 6: 60. 1969; Czerepan., Vasc. Pl. Russia States 187. 1995; S. bornmülleri Gand. in Bull. Soc. Bot. France 60: 422. 1913; S. carinatiformis Kinzik. in Izv. Akad. Nauk Tadjik., Otd. Biol. Nauk 3: 26. 1962; Soskov in Ovcz., Fl. Tadzh. SSR 3: 400. 1968.

Annual, 10-30 cm, erect. Stem profusely branched at base, the lowermost branches ascending, sometimes longer than main stem, the upper usually spreading, terminating into numerous loose 0.5-3(7) cm long and 3-4 mm wide spikes; lower part of the plant in young stage invested in arachnoid indumentum, formed by delicate, interwoven, to 4 mm long, smooth hairs; upper parts greyish to glaucous with simple ± vesicular hairs. Lowermost leaves filiform, almost linear, spreading to recurved, 5-7(-10) x 0.5-0.75-1.2 mm, obtuse, the upper needle-like to subulate, to 3 mm long, at base up to 1.5 mm wide. Lower and middle bracts leaf-like, 2-4 mm long, longer than bracteoles and flowers, the upper shorter than bracteoles and tepals, triangular, 1.3-2 x 1.2-1.4 mm, strongly gibbous. Bracteoles semi-circular, the loweer caudate, the upper apiculate, 1.5-2.2 x 2.5-3 mm, tightly appressed to and shorter than the flower, in fruiting stage together with the bract forming a very regular cup. Tepals ovate with obtuse to gently acute apex, 1.5-2.5 mm long, the outer 1.2-1.4 mm wide, often purplish or yellowish at the exposed tip, transverse line at 1/4, green blotch large, triangular, above the line densely covered by vesicular hairs, the margins ciliate by flexuose hairs, below almost glabrous or towards the base with apically flexuose hairs forming sometimes a ring. Anthers 0.9-1.4 mm, narrow triangular, often sagittate, divided up to the appendage; appendages semi-circular to quadrangular with rounded edges, 0.2-0.3 x 0.2-0.25 mm, not distinctly separated from anther body; filaments linear, 2-2.5(3) x 0.3 mm; disc thick, rim-like, 0.15 mm wide, with broadly triangular to semi-globular lobes, glandular but without papillae. Ovary ovoid to almost conical; style 0.5-1.0 mm long; stigmas in upper part revolute, 0.7-1-1.5 mm long, flat or slightly furrowed, linear, c. 0.2 mm wide, inside with short papillae. Fruit 7-10 mm in diam., wings subequal, with a prominent keel reaching to periphery, very variable in shape, semi-circular to broadly ovate and the margins completely overlapping or narrow throughout and margins free resulting in a ± star-like shape, wing margins entire, crenate or dentate, wings usually light brown, in young stage sometimes yellow; tepals above the wings forming a regular, weakly ribbed cone; tepals below the wings forming a flat bowl, base flat, back moderately hardened, with prominent middle veins and often with a basal ring of hairs. Utricle 2-2.5 mm in diam., brown.

Fl. Per.: June-September.

Holotype: [Uzbekistan] Dist. Tashkent, near Chanak at Syr Darya river, higher places, IX. 1907, Sokolov (LE!).

Known as a component of semi-desert communities on skeletal soil of eroded slopes and lower terraces of dry river beds. The species is closely allied to S. sclerantha and without mature fruits they are sometimes difficult to separate. But as the latter differs also by being a strict psammophyte, both species are kept separately; Distribution: From the Caspian lowlands east to S Kazakhstan, S. Kirghistan and Tadzhikistan, southwards to C and S Iran (higher altitudes), and through S and SE Afghanistan to Pakistani Baluchistan.

Irano-Turanian.