Marrubium

PLANT: Biennial or perennial taprooted herbs, pubescent; stems usually erect, often much branched from crown. LEAVES: long‑petiolate to subsessile; blades ovate to orbicular; margin mostly toothed. INFLORESCENCE: verticillate, interrupted; bracts leafy. FLOWERS: subsessile; calyx zygomorphic or actinomorphic, enlarging slightly in fruit, the teeth 5 or 10, the apices spinose, straight or curled; corolla zygomorphic, 2‑lipped, the tube shorter than calyx, the upper lip flat, 2‑lobed, the lower lip 3‑lobed; stamens 4, included in corolla tube, the anther sacs divaricate with none abortive; ovary sessile, lobed to base; stigma evenly 2‑lobed. NUTLETS: oblong to ovoid, glabrous, the epidermis cells rounded or depressed. REFERENCES: Christy, Charlotte M. Lamiaceae. 2003. J. Ariz. - Nev. Acad. Sci. Volume 35(2).

Cal nearly regular, 5-10-toothed, densely villous in the throat; cor strongly 2-lipped, the upper lip ascending, oblong, nearly straight, entire or shortly bifid, the lower lip spreading, 3-lobed, the central lobe the largest and often emarginate; stamens 4, included in the cor-tube, the lower pair slightly the longer; pollen-sacs divaricate, soon confluent; style gynobasic; nutlets truncate; perennials, generally woolly, with toothed or incised, rugose lvs, the fls in dense axillary clusters; bracteoles usually present. 35, Old World.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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