Herbs, perennial, glabrous or pubescent, from stout, ± woody taproots. Stems erect to reclining, often clambering through other vegetation, unarmed, with glutinous bands on internodes. Leaves subsessile to long petiolate, unequal in size in each pair; blade thin or thick and slightly fleshy, base ± asymmetric. Inflorescences terminal and axillary, pedunculate, racemose; bracts deciduous, 1 at base of each pedicel, distinct, lanceolate, thin, translucent. Flowers bisexual, chasmogamous and/or cleistogamous; perianth of cleistogamous flowers forming low dome atop basal portion; perianth of chasmogamous flowers slightly bilaterally symmetric, funnelform, strongly oblique, constricted beyond ovary, tube flared, limbs 5-lobed; stamens 5 (fewer in cleistogamous flowers), exserted; styles exserted beyond anthers; stigmas capitate. Fruits clavate, ± gibbous abaxially, often gently incurved adaxially, stiffly coriaceous; ribs 10, not well defined, with or without interrupted ridges or tubercules, glabrous.

Distribution

sw United States, Mexico.

Discussion

Species 2 (2 in the flora).

In its racemose inflorescence and clavate fruits, Cyphomeris resembles some species of Boerhavia Linnaeus, where its retention has been suggested by F. R. Fosberg (1978).

Selected References

Mahrt, M. and R. Spellenberg. 1995. Taxonomy of Cyphomeris (Nyctaginaceae) based on multivariate analyses of geographic variation. Sida 16: 679–697.

Lower Taxa

Cyphomeris crassifolia, Cyphomeris gypsophiloides

Key

1	Leaf blades glabrous or glabrate, lanceolate to linear, margins entire; fruits 8-11(-14) mm, striate, sometimes weakly warty	Cyphomeris gypsophiloides
1	Leaf blades pubescent, ovate, broadly oblong, or rhombic, margins usually sinuate; fruits 6-8 mm, usually prominently warty on gibbous side	Cyphomeris crassifolia