Lycopus 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

Perennial herbs, with horizontal rhizomes or runners, sometimes tuberiferous, weakly or not aromatic, with simple hairs

Morphology Leaves

Leaves opposite, petiolate or sessile, ovate to lanceolate or linear, variously toothed or pinnatifid

Morphology Reproductive morphology Inflorescences

Inflorescence of tight, axillary verticillasters

Morphology Reproductive morphology Flowers

Flowers sessile to subsessile

Morphology Reproductive morphology Flowers Calyx

Calyx actinomorphic to weakly zygomorphic, not accrescent, tubular-campanulate to campanulate, 4-5-nerved, 4-5-lobed, lobes ± equal, ovate to lanceolate-subulate or aristate, throat glabrous

Morphology Reproductive morphology Flowers Corolla

Corolla white, usually weakly zygomorphic, occasionally ± actinomorphic or 2-lipped, lobes usually 4, posterior and sometimes anterior lobe larger than lateral ones, all entire or posterior lobe bifid, tube straight

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 2 (posterior pair reduced to staminodes or absent), exserted or included, filaments glabrous, thecae parallel to divergent, separate at dehiscence

Morphology Reproductive morphology Flowers Gynoecium Style

Style often expanded near base to form flange covering top of ovary

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma-lobes equal or unequal

Morphology Reproductive morphology Flowers Disc

Disc symmetrical

Morphology Reproductive morphology Fruits

Nutlets obovoid-tetrahedral, often with conspicuously toothed to tuberculate apical crest, glabrous, inner and upper faces often densely glandular.

Note

2n = 22.  About fourteen species

Ecology

Wet habitats

Distribution

Mostly in the north-temperate zone (one species in Australia e introduced to New Zealand).