Erect perennia. herbs, with slender upright branches, alternate sessile narrow leaves, and white sessile flowers in narrow terminal spikes. Calyx-tube filiform, much prolonged beyond the ovary, 4-lobed. Petals 4, clawed, unequal. Stamens 8, declined, not appendaged by scales at the base; filaments filiform:. Ovary 1-celled; united styles slender; stigma 4-lobed, subtended by a cup-like border as in Gaura; ovules commonly 4. Fruit 8-ribbed, indehiscent, 1-celled, 1-seeded. Seed pendulous. [Greek, referring to the slender calyx-tube.]

A monotypic genus of the south-central United States.

1. Stenosiphon Linifòlium (Nutt.) Britton. Flax-Leaved Stenosiphon

Fig. 3073

Gaura linifolia Nutt. in Long's Exp. 2: 100.

1823. Stenosiphon virgatus Spach, Nouv. Ann.

Mus. Par. 4: 326. 1835. Stenosiphon linifolium Britton, Mem. Torr.

Club 5: 236. 1894.

Erect, slender, glabrous, 2°-5° high. Leaves sessile, lanceolate, linear-lanceolate or linear, acuminate or acute at the apex, narrowed or rounded at the base, entire, 1'-2' long, the upper ones much smaller; spikes dense, narrow, sometimes 1° long in fruit; flowers white, 4"-6" broad; calyx-tube very slender, 4"-5" long; fruit ovoid, pubescent, 1"-1 1/2" long, very much shorter than the linear-subulate bracts.

Prairies, hills and plains, Nebraska and Colorado to Texas. June-July.