752 LAMIACEAE 



stem sparingly and coarsely pubescent or glabrous; leaves glabroiis or nearly so. 

 Leaves merely coarsely serrate. 



Leavas tapering at the base, rather thin. 3. L. lucidus. 



Leaves roimded at the base, thicker. 4. L. aspvr. 



Leaves sinuately pinnatifld. .5. L. americanus. 



1. L, communis Bickn. Rootstock tuberous-thickened at the base of the 

 stem; stem 1-S (hii. hi^h, acutely angled; leaves 2.5-8 cm. long, lanceolate or 

 oblong-lanceolate, sharply serrate; calyx campanulate; corolla 2-3 mm. long; 

 lobes spreading. Wet places: Newf. — Va.-^Neb. — Ore.^B.C. Plain — /Su6- 

 mont. Au-S. 



2. L. velutinus Rydb. Stem 3-5 dm. high; leaf-blades lance-elliptic, 

 coarsely toothed, 4-10 cm. long, short-petioled ; calyx campanulate, copiously 

 pubescent, 2.5 mm. long; lobes lanceolate, acuminate, the upper two recurved; 

 corolla 3.5 mm. long, glandular-punctate. Low ground and swamps: Colo. — 

 Tex. — Miss. — Ark. Son. Au. 



3. L, lucidus Turcz. Stem stout, strict, 3-9 dm. high, sparingly pubescent 

 on the angles; leaves oblong-lanceolate, sessile or short-petioled, 5-15 cm. long, 

 sharply serrate; calyx-teeth subulate-lanceolate, nearly as long as the tube; 

 corolla little longer than the calyx. Wet soil, especially in thickets: Neb. — Kans. 

 — Ariz. — Calif. — B.C.; Asia. Plain — Suhmont. Jl-S. 



4. L. asper Greene. Stem 3-6 dm. high, obtusely angled; leaves firm, 

 narrowly lanceolate, acute, sessile, strongly serrate, 4^6 cm. long, very veiny, 

 rough on both sides; calyx-teeth ovate-lanceolate, acuminate. Wet places: 

 w Ont.— Neb.— B.C. Plain. Jl-Au. 



5. L. americanus Muhl. Stem sharply angled, puberulent or glabrous, 

 1-10 dm. high; leaves lanceolate in outline, petioled, acuminate, pinnatifid or 

 incised, 3-10 cm. long; calyx-teeth triangular-subulate, cuspidate, rigid; corolla 

 little exceeding the calyx. L. sinuatus Ell. Swamps and wet meadows: Newf. 

 —Fla.— Calif.— B.C. Plain— Suhmont. Je-0. 



26. MENTHA (Tourn.) L. Mint, Spearmint, Peppermint. 



Aromatic caulescent perennial herbs, with rootstocks. Leaves opposite, 

 punctate, toothed, usually petioled. Flowers perfect, in dense, axillary clusters. 

 Calyx campanulate, 10-ribbed, regular or nearly so, 5-lobed. Corolla funnel- 

 form or campanulate, nearly regular; lobes 4, the upper larger than the rest. 

 Stamens 4, anther-bearing, erect; anther-sacs 2, parallel. Nutlets smooth. 



Whorls of flowers forming terminal spikes. 1. M. spicata. 



Whorls of flowers all axillary. 



Stem and petioles densely pubescent with long villoiis hairs; leaves decidedly pubes- 

 cent. 2. M. lanala. 

 Stem and petioles retrorsely strigose or crisp-hairy with short hairs, or glabrous 

 below; leaves sparingly puberulent or glabrous. 

 Corolla 5-6 mm. long, open-funnelform; bracts lanceolate or linear-lanceolate, 

 usually exceeding the flower-clusters; leaves dark green, not strongly veined. 



3. M. occidcntalis. 

 Corolla 4-5 mm. long, salver-shaped-funnelform; bracts linear or subulate, shorter 



than the flower-clusters. 

 Leaf-blades tliin, dark green, not strongly veined, tapering gradually into 

 slender petioles, wliich equal or exceed the flower-clusters. 



4. i\/. glabrior. 

 Leaf-blades tliick, strongly veined, abruptly contracted into short petioles, 



which are much shorter than the flower-clusters. 

 Plant pale :jreen, stout, 4-8 dm. high; calyx-teeth much longer than broad. 



5. M. Penardi. 

 Plant usually purplish, low, 2-4 dm. high; calyx-teeth scarcely longer than 



broad. 6. M. rubella. 



1. M, spicata L. Stem erect, 3-5 dm. high, glabrous; leaves lanceolate, 

 sessile or nearly so, sharply serrate, 3-7 cm. long; spikes 5-10 cm. long; bracts 

 subulate-lanceolate, ciliate; calyx-teeth subulate; corolla glabrous. Spearmint. 

 Fields and waste places: N.S. — ^Fla. — Kans. — Minn.; Calif. — Utah — B.C.; nat. 

 from Eu. Plain — Suhmont. Jl-S. 



2. M. lanata (Piper) Rydb. Stem 3-6 dm. high; leaves short-petioled, 

 lanceolate or ovate, serrate, 2-7 cm. long, more or less pilose above, villous 

 beneath; bracts subulate, about equalling the flowers; cal^Tc 2.5-3 mm. long. 



