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 entire lance-oblong 3-nerved leaves, and small pale blue flowers on axillary 1–3-flowered peduncles. (Name from ἴσος, equal, and ἄνθος, flower, referring to the almost regular corolla.)
1. I. cærùleus, Michx. Corolla 2–3´´ long, little exceeding the calyx.—Dry or sterile ground, Maine to Ill., Minn., and southward. July, August.
3. TEÙCRIUM, Tourn. Germander.
Calyx 5-toothed. Corolla with the 4 upper lobes nearly equal, oblong, turned forward, so that there seems to be no upper lip; the lower lobe much larger. Stamens 4, exserted from the deep cleft between the 2 upper lobes of the corolla; anther-cells confluent. (Named for Teucer, king of Troy.)
1. T. Canadénse, L. (American Germander. Wood Sage.) Perennial, downy, erect (1–3° high); leaves ovate-lanceolate, serrate, rounded at base, short-petioled, hoary underneath, the floral scarcely longer than the oblique unequally-toothed calyx; whorls about 6-flowered, crowded in a long and simple wand-like spike; calyx canescent, the 3 upper lobes very obtuse or the middle one acutish; corolla purple, rose, or sometimes cream-color (6´´ long).—Low grounds; not rare. July–Sept.
2. T. occidentàle, Gray. Loosely pubescent; calyx villous with viscid hairs, the upper lobes acute or middle one acuminate; corolla 4–5´´ long; other wise like the last.—A western form, from Neb. southwestward, and extending eastward (Ont., and near Philadelphia).
4. ÁJUGA, L.
Calyx 5-toothed. Corolla with very short and as if truncate upper lip; the large and spreading lower lip with the middle lobe emarginate or 2-cleft. Stamens as in Teucrium, but anther-cells less confluent. (From α- privative, and ζυγόν (Latin jugum), yoke, from the seeming absence of a yoke-fellow to the lower lip of the corolla.)
A. réptans, L. Perennial, about 1° high, with copious creeping stolons; leaves obovate or spatulate, sometimes sinuate, the cauline sessile, the floral approximate, subtending several sessile blue flowers.—Naturalized near Saco, Maine, Montreal, etc. (Eu., N. Asia.)
5. COLLINSÒNIA, L. Horse-Balm.