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Key to families | Table of families and genera
This text currently parallels The Jepson Manual: Vascular Plants of California, Second Edition that is now available at the University of California Press.
Text appearing in blue on this page will not appear in the printed book; it will be displayed only on the Web. Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.
Perennial from rhizomes, glabrous to hairy.
Stem: generally ascending to erect, generally branched.
Leaf: petioled to sessile; blade elliptic to ovate or lanceolate, toothed to lobed.
Inflorescence: head-like in leaf axils or collectively spike- or panicle-like and subtended by bracts.
Flower: calyx ± radial, generally 10-veined, lobes 4–5, equal or not; corolla ± 2-lipped, lips generally equal, upper lip notched, lower lip 3-lobed; stamens 4, ± equal, generally exserted, filaments glabrous, anthers segments parallel, distinct.
Fruit: nutlets ± ellipsoid, tip rounded.
18 species: temperate. North America, Eurasia. (Latin: ancient name for mint) [Tucker et al. 1980 Taxon 29:233–255] Cult for oils, flavoring, herbs. Hybrids in CA generally sterile, spreading from rhizomes.
Unabridged note: Many cultivated and naturalized populations derived from hybridization, generally polyploid, some sterile, reproducing vegetatively.
1. Calyx interior with ring of hairs; vegetative stems decumbent, flowering stems upright ..... M. pulegium
1' Calyx interior glabrous or hairs few, scattered; both vegetative and flowering stems upright
2. Infl generally axillary
3. All leaves ± equal in size, blade generally ovate, generally spicy-scented ..... M. arvensis
3' Lvs reduced in size distally, blade generally linear to lanceolate, generally pennyroyal- or spearmint-scented
4. Lvs gradually reduced distally on stem, generally pennyroyal-scented ..... M. canadensis
4' Lvs greatly reduced distally on stem, generally spearmint-scented (fruit-scented)
5. Calyx 1.5–3 mm, lobes triangular ..... M. ×gracilis
5' Calyx 2.5–4 mm, lobes sharply tapering ..... M. ×smithiana
2' Infl terminal
6. Infl generally head-like, clustered at distal 3–5 nodes
7. Blade generally ovate, generally lavender- and citrus-scented ..... M. aquatica
7' Blade ovate to lanceolate, generally peppermint- or spearmint-scented (lavender and citrus) ..... M. ×piperita
6' Infl spike-like
8. Lvs wrinkled
9. Blade lance-oblong, glabrous (branched-hairy abaxially), spearmint-scented ..... M. spicata (2)
9' Blade ovate, with scattered many-branched hairs abaxially, fruit-scented ..... M. suaveolens
8' Lvs not wrinkled, occasionally deeply veined
10. Blade lanceolate to lance-oblong
11. Blade widest near middle, hairs unbranched; fertile anthers ± 0.3–0.4 mm; generally musty-scented ..... M. longifolia
11' Blade widest near base, occasionally branched-hairy abaxially; fertile anthers ± 0.4–0.5 mm; generally spearmint-scented ..... M. spicata (2)
10' Blade oblong to ovate
12. Calyx ciliate; fertile anthers 4; leaf blade base tapered to ± lobed; corolla 2.5–3.5 mm; GV, CCo, TR ..... M. ×rotundifolia
12' Calyx generally canescent; fertile anthers generally 0; leaf blade base tapered; corolla 3–4 mm; TR ..... M. ×villosa
Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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