* Leaves with a flat expanded surface.
S. Rhodiola: stems erect, stout, simple, 1/2-3/4 foot high, leafy to the top; leaves alternate, sessile, obovate or oblong, slightly toothed; flowers dioecious, yellow or rarely purplish, forming dense cymes, surrounded by the upper leaves, the males with eight stamens longer than the petals, the females with four carpels. - Rosewort. - Clefts of alpine rocks. Fl. May, June. The smell of the rootstock, when drying, has been compared to that of roses. It is sometimes called Rhodiola rosea.
S. Telephium: stems hard, erect, simple, 1-2 feet high or more; leaves scattered, obovate or oblong, coarsely-toothed; flowers numerous, purple, forming a handsome terminal corymb; stamens shorter than the petals. - Orpine. - Borders of fields, hedge-banks, and bushy places. Fl. July, August.
** Leaves tumid, as thick as broad. † Flowers white or red.
S. anglicum: stems glabrous, decumbent, three inches high, much branched at the base; leaves short, thick, almost globular, crowded on the short barren branches, more loosely scattered and occasionally opposite on the flowering ones; flowers white, occasionally tinged with pink, in a short irregular cyme. - Rocky or stony places. Fl. July.
S. villosum: annual; stems erect, nearly simple, 3-4 inches high, the upper part of the plant with short viscid hairs; leaves linear, flat above, alternate or scattered; flowers few, pale dingy rose colour, in a small, loose, terminal cyme. - Mountain bogs and stony rills. Fl. June, July.
†† Flowers yellow.
S. acre: stems numerous, short, tufted, glabrous, procumbent, the erect ascending flowering branches 1-3 inches high; leaves small, thick, ovoid, or sometimes nearly globular; flowers bright yellow, in small terminal cymes. - Wall Pepper. - Walls and rocks. Fl. June.
S. rupestre: tufted, with numerous short barren shoots, 1-3 inches long, the terminal flowering stems ascending 1/2-1 foot high; leaves narrow, cylindrical, shortly spurred at the base; flowers large, yellow, forming a terminal cyme of 4-8 recurved branches, each bearing 3-6 sessile flowers. - Old walls and stony places. Fl. July.