Erect usually branched glaucous annual herbs, with opposite sessile or clasping entire leaves. Flowers large, blue, purple or white, long-peduncled, axillary and terminal, solitary or paniculate. Calyx deeply 5-6-cleft, the lobes lanceolate, acuminate, keeled. Corolla broadly campanulate, deeply 5-6-lobed, the lobes oblong or obovate, usually erose-denticulate, convolute in the bud. Stamens 5-6, inserted on the throat of the corolla; filaments filiform; anthers oblong, versatile, at length recurved, or remaining nearly straight. Ovary 1-celled; style filiform; stigma 2-lamellate. Capsule oblong or ovoid, 2-valved. Seeds small, numerous, foveolate. [Greek, open-mouth, referring to the corolla.]

Four species, natives of the southern United States, New Mexico and the West Indies. Type species: Eustoma silenifolium Salisb.

3 Eustoma Salisb Parad Lond Pl 34 1806 17

1. Eustoma Russellianum (Hook.) Griseb. Russell's Eustoma

Fig. 3346

Lisianthus Russellianus Hook. Bot. Mag. pl. 3626. 1839.

Lisianlhus glaucifolius Nutt. Trans. Am. Phil. Soc. (II.) 5:197. 1833-37. Not. Jacq. 1786.

E. Russellianum Griseb. in DC. Prodr. 9: 51. 1845.

Stem terete, rather stout, 1°-2 1/2° high. Leaves oblong or ovate-oblong, 3-5-nerved, the upper usually acute at the apex, cordate-clasping at the base, 1 1/2'-3' long, the lower usually obtuse at the apex and narrowed to a sessile or slightly auricled base; peduncles 1'- 4' long, stout, bracted at the base, the bracts lanceolate-subulate, small; flowers 2'-3' broad; calyx-lobes long-acuminate, shorter than the purple corolla; corolla-lobes obovate, about 4 times as long as the tube; style slender; anthers remaining nearly straight; capsule oblong, pointed.

On prairies, Nebraska to Louisiana, Colorado, Texas, New Mexico and Mexico. Canada pest. May-Aug.