Sideritis L.

Harley, R.M. et al. (2004). Labiatae, in The Families and Genera of Vascular Plants (K. Kubitzki, ed. in chief) VI: 167-275. Springer-Verlag, Berlin, Heidelberg, New York.

Morphology General Habit

Annual or perennial, sometimes rhizomatous herbs or shrubs, with simple and sometimes branched hairs, usually aromatic

Morphology Leaves

Leaves often narrow, usually toothed, sessile to petiolate

Morphology Reproductive morphology Inflorescences

Inflorescence thyrsoid or sometimes racemoid, often dense

Morphology Reproductive morphology Inflorescences Bracteoles

Bracteoles present or absent

Morphology Reproductive morphology Flowers Calyx

Calyx zygomorphic or almost regular, 5-lobed, lobes subequal or unequal (1/4), mostly triangular, often spinose, tube often barbate in throat

Morphology Reproductive morphology Flowers Corolla

Corolla 2-lipped, 4-5-lobed (1-2/3), usually yellow or white, sometimes purple, posterior lip flat or almost so, deeply emarginate to entire, tube shorter than calyx

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens included in corolla-tube, thecae confluent

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma-lobes unequal

Morphology Reproductive morphology Fruits

Nutlets rounded at apex.

Note

2n = 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 50, 56.  About 140 species Mendoza-Heuer (1977) recognizes two subgenera: subg. Sideritis and subg. Marrubiastrum, the latter endemic to Macaronesia.

Ecology

Various habitats

Distribution

Macaronesia, Mediterranean region to Russia, Tibet and Western China.  Introduced to South-Central U.S.A.