LAMIACEAE

MINT FAMILY

Dieter H. Wilken, except as specifed

Annual, perennial herb, shrub, glabrous to hairy, generally aromatic
Stems generally erect, generally 4-angled
Leaves generally simple to deeply lobed, opposite, generally gland-dotted
Inflorescence: cyme, generally clustered around stem, head-like, separated by evident internodes (terminal in Monardella ) or collectively crowded, spike-like to panicle-like (sometimes raceme or flowers 2–12); subtended by leaves or bracts; flowers sessile or pedicelled
Flower generally bisexual; calyx generally 5-lobed, radial to bilateral; corolla generally bilateral, 1–2-lipped, upper lip entire or 2-lobed, ± flat to hood-like, sometimes 0, lower lip generally 3-lobed; stamens generally 4, generally exserted, paired, pairs unequal, sometimes 2, staminodes 2 or 0; ovary superior, generally 4-lobed to base, chambers 2, ovules 2 per chamber, style 1, arising from center at junction of lobes, stigmas generally 2
Fruit: nutlets 4, generally ovoid to oblong, smooth
Genera in family: ± 200 genera, 5500 species: worldwide. Many cultivated for herbs, oils (Lavandula , lavender; Mentha , mint; Ocimum , basil; Rosmarinus , rosemary; Thymus , thyme), some cultivated as ornamental (in CA Cedronella , Leonotis , Phlomis )
Reference: [Cantino & Sanders 1986 Syst Bot 11:163–185]

MENTHA

MINT

Perennial from rhizomes, glabrous to hairy
Stems generally ascending to erect, generally branched
Leaf petioled to sessile, elliptic, ovate, or lanceolate, toothed to lobed
Inflorescences axillary, each head-like and subtended by leaves, or collectively spike- or panicle-like and by bracts
Flower: calyx ± radial, generally 10-veined, lobes equal or unequal; corolla ± 2-lipped, lips generally equal, upper lip notched, lower lip 3-lobed; stamens 4, ± equal, generally exserted; style lobes unequal
Species in genus: 25 species: temp. North America, Eurasia
Etymology: (Latin: ancient name for mint)
Reference: [Tucker, Harley, & Fairbrothers 1980 Taxon 29:233–255]
Cult for oils, flavoring, herbs. Many cultivated and naturalized populations derived from hybridization, generally complexly polyploid, some sterile, reproducing vegetatively.

Introduced

M. X piperita L.

PEPPERMINT

Stem 3–10 dm, generally glabrous
Leaf 3–6(8) cm; petioles 3–8 mm; blade ovate to lanceolate, base tapered to slightly lobed, tip acute, generally serrate, lower surface generally glabrous
Inflorescences each head-like, clustered at upper 3–5 nodes, subtended by ovate to linear-lanceolate bracts
Flower: calyx 2.5–4 mm, generally glabrous or lobes ciliate; corolla 3.5–6 mm, white, pink, or violet; stamens generally included
Chromosomes: 2n=66,72,84,120
Ecology: Moist places, fields
Elevation: < 2500 m.
Bioregional distribution: California Floristic Province, cultivated elsewhere
Distribution outside California: to Canada, e US; naturalized from cultivated in Europe
Hybrid between M. aquatica L. & M. spicata L. Plants generally sterile, widely cultivated, spreading from rhizomes
Synonyms: M. citrata Ehrh