Leonurus

PLANT: Biennial or perennial taprooted herbs, pubescent; stems erect, single or branched freely from crown. LEAVES: long‑petiolate; blades obovate or elliptic to linear‑lanceolate; margins palmately 3‑5‑lobed or cleft, coarsely toothed. INFLORESCENCE: verticillate, interrupted; bracts leafy. FLOWERS: sessile; calyx zygomorphic, enlarging slightly in fruit, the lobe apices spinose or aristate; corolla zygomorphic, 2‑lipped, the tube equaling or shorter than calyx, the upper lip entire and slightly concave, the lower lip 3‑lobed; stamens 4, held alongside upper lip, the anther sacs parallel with none abortive; ovary sessile, lobed to base; stigma evenly 2‑lobed. NUTLETS: obconic, smooth except apex densely hairy. x = 9, 10. NOTES: 12 spp.; Eurasian. (Greek: leon = lion + oura = tail). REFERENCES: Christy, Charlotte M. Lamiaceae. 2003. J. Ariz. - Nev. Acad. Sci. Volume 35(2).

Cal turbinate, 5-10-nerved, the lobes prolonged into stiff slender spines, the 2 lower often slightly larger or deflexed; cor strongly bilabiate, the upper lip entire and galeately rounded, the lower spreading or deflexed, 3-lobed, with obcordate central lobe and oblong lateral lobes; stamens 4, ascending under the upper lip, the lower pair equaling or longer than the upper; pollen-sacs mostly parallel; nutlets triquetrous, truncate and hairy at the top; erect herbs with toothed or cleft, petiolate lvs and white to pink fls crowded in dense verticils subtended by bracteal lvs and by linear to subulate bracts; forming long, interrupted terminal spikes. 10, mostly temp. Eurasia.

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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