344 LABIATE. (MINT FAMILY.) 



namely, the short teeth of the calyx upward, &c. Corolla blue, varying to pur- 

 ple, rarely white, small ; in summer and autumn. (Name composed of dpi£, 

 hair, and or^/xa, stamen, from the capillary filaments.) 



1. T. dichotomum, L. (Bastard Pennyroyal.) Leaves lance-oblong 

 or rhombic-lanceolate, rarely lance-linear, short-petioled. — Sandy fields, New 

 England to Kentucky, and southward, chiefly eastward. — Stamens £' long. 

 Corolla blue : a pink variety near Hartford, Conn., C. H. Olmstead. 



2. T. line&re, Nutt. Leaves linear, nearly smooth. — Sandy pine barrens 

 of New Jersey, and southward. — More slender and less forked than the last. 



3. ISANTHUS, Michx. False Pennyroyal. 



Calyx bell-shaped, 5-lobed, equal, enlarged in fruit. Corolla little longer than 

 the calyx ; the border bell-shaped, with 5 nearly equal and obovate spreading 

 lobes. Stamens 4, slightly didynamous, incurved-ascending, scarcely exceeding 

 the corolla. — A low, much branched annual, clammy-pubescent, with nearly en- 

 tire lance-oblong 3-nerved leaves, and small pale blue flowers on axillary 1-3- 

 flowered peduncles. (Name from taos, equal, and avdos, flower, referring to the 

 almost regular corolla.) 



1. I. csertlleus, Michx. — Gravelly banks and fields, Maine to Illinois, and 

 southward. July, Aug. — Corolla 2" long. 



4. MENTHA, L. Mint. 



Calyx bell-shaped or tubular, 5-toothed, equal or nearly so. Corolla with a 

 short included tube ; the bell-shaped border somewhat equally 4-cleft ; the upper 

 lobe broadest, entire or notched. Stamens 4, equal, erect, distant. — Odorous 

 perennial herbs, with the small flowers mostly in close clusters, forming axil- 

 lary capitate whorls, sometimes approximated in interrupted spikes ; produced 

 in summer ; of two sorts as to the length of the stamens in most species. 

 Corolla pale purple or whitish. (MivOt) of Theophrastus, from a Nymph of that 

 name, fabled to have been changed into Mint by the jealous Proserpine.) 

 * Inflorescence terminal, forming narrow spikes : leaves sessile or nearly so. 



1. M. rotundifolia, L. (Round-leaved Mint.) Soft-hairy or downy ; 

 haves round-ovate and somewhat heart-shaped, rugose, crenate-toothed. — Wet 

 places, Cumberland, Maine, J. Blake. (Adv. from Eu.) 



2. M. viridis, L. (Spearmint.) Nearly smooth; leaves oblong- or ovate- 

 lanceolate, unequally serrate. — Wet places : common. (Nat. from Eu.) 



* * Inflorescence mostly terminal, forming interrupted spikes or heads : leaves petioled. 



3. M. piperita, L. (Peppermint.) Smooth; leaves ovate-oblong, acute; 

 spikes loose. — Var. subhirsuta, Benth., has the petioles, veins of the leaves, 

 &c. rather hairy. — Low grounds, and along brooks : less naturalized tban the 

 last; and like it multiplying rapidly by running under-ground shoots. (Nat. 

 from Eu.) 



4. M. aquAtica, L. (Water Mint.) Pubescent or smoothish ; leaves 

 ovate or round-ovate ; flowers in a terminal globular or interrupted and oblong 

 head, often with one or more clusters in the axils of the upper leaves ; calyx and 



