Petasites
(an old Greek name used by Dioscorides, from petasos, an umbrella; alluding to the size of the foliage). Including Nardosmia. ORD. Compositae. A genus comprising about a dozen species of hardy, more or less white-tomentose or woolly herbs, with perennial rhizomes or stems, natives of Europe, Asia, and North America. Flower-heads purple or white, rarely yellowish-white, heterogamous, mediocre, racemose or thyrsoid-paniculate at the tips of the scapes; involucre campanulate or cylindrical; receptacle flat, naked. Leaves radical, often ample, cordate or reniform. Scapes or stems many-headed, with the leaves reduced to alternate scales, or rarely with the lower ones more evolute. Many of the species formerly included under Tussilago are now referred, by Bentham and Hooker, to this genus. All succeed in any ordinary soil, and may be increased by divisions. Some of the species are rather pretty. The following are among the best-known.
P. alpina (alpine). A synonym of Homogyne alpina.
P. fragrans (fragrant).* fl.-heads white, sweet-smelling; involucral scales acute. February. l. cordate at base, orbiculate-cartilaginously toothed; lobes sub-rotund at base. h. 6in. South-western Europe, 1806 (naturalised here and there in Britain). (G. C. n. s., ix. 147.) SYN. Tussilago fragrans (B. M. 1388).
P. frigida (frigid).* fl.-heads white. April and May. l. rounded, somewhat reniform, white-woolly beneath, palmately and deeply five to seven-lobed, 6in. to 10in. broad; lobes toothed and cut. h. 6in. Arctic regions, 1778. SYN. Tussilago frigida.
P. niveus (snowy). fl.-heads white, borne on simple pedicels. March. l. broadly cordate, sub-triangular, toothed, slightly glabrous above, snowy-tomentose beneath; lobes divaricate, sub-acute. h. 1ft. Europe, 1713. P. vulgaris (common). Bog Rhubarb; Butter Bur. fl.-heads borne in cylindric panicles, 3in. to 10in. long, the female longest, elongating after flowering; pedicels slender. March to May. l. 3in. to 3ft. in diameter, reniform or orbicularly cordate, irregularly toothed, white or cobwebby beneath, and, when young, above also. Stems 4in. to 18in. high, stout, purplish below. Europe (Britain), &c. SYNS. Tussilago hybrida (this name represents the female plant) and T. Petasites. (Sy. En. B. 783, 784.)