Caryophyllaceae subfam. Paronychioideae
Herbs [small shrubs], annual, biennial, or perennial; taprooted, not rhizomatous. Stems prostrate to ascending or erect, simple or branched. Leaves opposite, distalmost or all sometimes alternate, bases connate or not, sometimes petiolate, stipulate; stipules ovate or deltate to lanceolate or spatulate, scarious; blade needlelike or often spatulate to elliptic or suborbiculate, seldom succulent. Inflorescences terminal or axillary cymes or flowers solitary; bracts foliaceous or usually scarious; involucel bracteoles absent. Pedicels present or flowers sessile. Flowers bisexual or sometimes unisexual (the plant then dioecious or polygamodioecious); perianth and androecium perigynous; hypanthium usually cup-shaped or cylindric or conic to urceolate; sepals (3–)5, distinct or rarely connate proximally, apex often hooded or awned (awn often subapical); petals absent; stamens absent or 1–5, in 1 whorl arising from hypanthium rim; staminodes absent or 5 (16–19 in Achyronychia); ovary 1-locular; styles 1–3, distinct or sometimes connate proximally; stigmas 2 or 3. Fruits utricles, indehiscent or sometimes opening by 3 or 8–10 valves; carpophore absent. Seeds 1, white to tan or brown to black, ovoid to reniform, not or slightly laterally compressed; embryo peripheral or central, curved or straight. x = 7, 8, 9.
s North America, South America (Andean region), Europe (Mediterranean region), Asia (Mediterranean region, e to India), Africa (Mediterranean region).
Genera 17, species ca. 200 (6 genera, 32 species in the flora).
Paronychioideae is characterized by the presence of stipules, petaloid staminodes, and usually indehiscent utricles. It is of similar size to Polycarpoideae; about two-thirds of the species are found in Paronychia and Herniaria. Paronychioideae is sometimes segregated from Caryophyllaceae as Illecebraceae, due to emphasis on the utricle; molecular data does not support recognition of Illecebraceae (M. Nepokroeff et al. 2002; R. D. Smissen et al. 2002). While there are some features shared with Polycarpoideae (stipules, solanad type of embryogeny), floral reduction is more pronounced in this group.
Tentatively, Corrigioleae (Telephium and Corrigiola) is included here. M. G. Gilbert (1987) proposed transferring this tribe to Molluginaceae, noting that the morphological anomalies within Caryophyllaceae, including alternate leaves, exhibited in these plants were reduced under such an alignment. M. Nepokroeff et al. (2002) retained the tribe within Caryophyllaceae, placed as a sister group to the rest of the family.