Herbs [small shrubs], winter annual, annual, or perennial; taprooted, not rhizomatous. Stems prostrate to erect, simple or branched. Leaves opposite or sometimes appearing whorled, bases connate or not, sometimes petiolate or often sessile, stipulate; stipules ovate or deltate to lanceolate or bristlelike, scarious; blade subulate or subtriangular to linear and threadlike or spatulate to ovate or orbiculate, seldom succulent. Inflorescences terminal or axillary cymes, or flowers solitary; bracts scarious or absent; involucel bracteoles absent. Pedicels present or flowers sessile. Flowers bisexual or rarely unisexual; perianth and androecium hypogynous or perigynous; hypanthium absent or dish- or cup-shaped; sepals 5, distinct or sometimes connate proximally, hooded (Drymaria, Polycarpon) or not, awned (Polycarpon) or not; petals absent or (3–)5, blade clawed (Drymaria) or not, auricles absent, coronal appendages absent, blade apex entire, erose, or 2(–4)-fid, sometimes emarginate; stamens (1–)3–5(–10), in 1 or 2 whorls, usually arising from base of ovary or from rim of hypanthium (Spergula, Spergularia); staminodes absent; ovary 1-locular; styles 1 or 3, occasionally 2 or 5, distinct or sometimes connate proximally; stigmas 3, occasionally 2 or 5. Fruits capsules, opening by 3 or 5, occasionally 4 valves; carpophore sometimes present. Seeds 3–150+, whitish or tan to often brown or black, ± triangular, pyriform, or reniform to circular, subglobose or laterally compressed to angular (Polycarpon); embryo peripheral, curved or rarely annular to spirally curved (Spergula). x = [7], 8, 9, (11), 12.

Distribution

w North America (including Mexico), w South America, Europe (Mediterranean region), Asia (Mediterranean region), Africa (Mediterranean and tropical regions), less diverse in temperate areas.

Discussion

Genera 16, species ca. 210 (7 genera, 28 species in the flora).

More commonly recognized as a tribe, Polycarpoideae is characterized by the presence of stipules, well-developed petals, and capsules. It is a relatively small group, with about four-fifths of the species in Drymaria, Polycarpaea, and Spergularia. Although clearly stipulate, Spergularia clusters with members of Alsinoideae in recent molecular studies (M. Nepokroeff et al. 2002; R. D. Smissen et al. 2002).

Selected References

None.

Lower Taxa

Drymaria, Loeflingia, Polycarpaea, Polycarpon, Spergula, Spergularia, Stipulicida