Herbs, annual, biennial, or perennial, sometimes rhizomatous and/or stoloniferous, or with branched caudices (M. parvifolia), sometimes bulbiferous, succulent, glabrous. Stems prostrate to decumbent or erect, usually branched, often rooting at nodes. Leaves cauline and sometimes basal; basal leaves in rosettes; cauline leaves 3 or more, alternate, opposite, or secund, distinct, not articulate at base, somewhat to markedly clasping, attachment points linear, petiolate or sessile; blade linear, oblong, lanceolate or oblanceolate to rhombic, ovate, or suborbiculate. Inflorescences axillary or terminal, racemose, somewhat to markedly secund (at least terminally), ebracteate or 1-bracteate at base of each flower. Flowers radially symmetric (slightly irregular in M. fontana), not showy (except in M. parvifolia and M. bostockii), occasionally replaced by bulbils in M. chamissoi; sepals persistent, unequal; petals 5, sometimes absent, usually distinct (connate proximally in M. fontana); stamens 3-5 (occasionally 2 in M. howellii); ovary globose or linear-oblong, ovules 3; style 1; stigmas 3. Capsules 3-valved, longitudinally dehiscent from apex, valves not deciduous, margins involute. Seeds 1-3, black, rounded, tuberculate (appearing smooth in M. parvifolia); elaiosome absent or, less than 1 mm. x = 7, 8, 10, 11. The classification of Montia is in transition. It is widely recognized that the genus as traditionally treated is a rather disparate assemblage of species, albeit closely related. Several segregate genera have been described, but as R. C. Carolin (1993) has observed, 'while some are almost certainly recognizable at the generic level, the others probably less certainly.' With the current legitimate uncertainty, it is appropriate to treat Montia here in the broad, traditional sense. To do otherwise is to give the impression that we know more about the relationships of the species than is actually the case.
Sep 2, herbaceous, persistent; pet 3 or 5, often slightly unequal, sometimes connate below; stamens as many as and opposite the pet, or some members of the cycle missing; ovules and style-branches 3; fr a 3-valved capsule with 1-3 seeds; fibrous-rooted annual or perennial herbs without basal lvs, ours with several pairs of opposite lvs, the fls in axillary or terminal racemes, or solitary in the axils, or in small axillary cymules. 50, mostly N. Amer.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.