LABIATE FAMILY 38 1 



17. Ballota. — Calyx funnel-shaped, with 5 broad, spreading, 

 prickly teeth ; anthers smooth, bursting lengthwise. 



***** Stamens 4, parallel, the 2 upper shorter; nutlets united, 

 wrinkled 



1 8. Tetjcrium. — Calyx tubular, 5-toothed ; upper lip of corolla 

 deeply 2-cleft. 



19. Ajuga. — Calyx ovoid, 5-cleft ; upper lip of corolla very 

 short, notched. 



1. Mentha (Mint). — Strongly-scented herbs, with creeping 

 rhizomes and runners; flowers small, in many-flowered whorls, 

 often crowded, with small bracts, into terminal spikes ; calyx with 

 5 equal teeth ; corolla campanulate, nearly polysymmetric, 4-lobed, 

 with a very short tube ; stamens 4 ; equal, erect, distant, smooth ; 

 nutlets free, smooth. (Name, the Classical name of the group.) 



* The species are very difficult to distinguish, graduating into 

 one another, and apparently also forming hybrids. 



t Whorls forming terminal spikes, with minute bracts 



1. M. rotundifdlia (Round-leaved Mint). — A viscid plant, 1 — 3 

 feet high ; stem somewhat woody, usually much branched ; leaves 

 sessile, broadly elliptical, remarkably blunt, often cordate, much 

 wrinkled, and nearly smooth above, shaggy beneath ; flowers lilac 

 or white, in dense, cylindrical, slightly interrupted spikes ; bracts 

 lanceolate ; corolla hairy. — Waste ground ; not common. The 

 scent is acrid and powerful, but not agreeable. — Fl. August, 

 September. Perennial. 



2. M. alopecuroides , intermediate between the preceding and 

 following species, has its runners underground ; its leaves slightly 

 stalked and very hairy, but not felted, beneath, and its spikes 

 short and stout, or conical-cylindrical. — Chiefly in the east of 

 England ; rare. — Fl. August, September. Perennial. 



3. M. longifolia (Horse Mint). — A strong- but sweet-scented 

 plant, usually growing in masses, 2 — 3 feet high, with sub-sessile, 

 oblong-lanceolate, acute, serrate leaves, more or less hairy above, 

 silky and white beneath ; flowers lilac, in a dense, slender, nearly 

 or quite uninterrupted spike ; bracts awl-shaped ; corolla hairy. — 

 Damp waste ground ; frequent. — Fl. August — September. Peren- 

 nial. 



4.* M. viridis (Spearmint). — Probably a cultivated form of the 

 preceding, escaped from gardens ; leaves sessile, glabrous, lanceo- 

 late, acute, serrate; spike slender, cylindrical, interrupted; corolla 

 smooth. — Wet places ; rare. — This is the form commonly cultivated 



