Holosteum

Herbs, annual or winter-annual. Taproots slender. Stems ascending to erect, simple or branched, terete. Leaves forming basal rosette, connate proximally into sheath, petiolate (proximal leaves) or sessile (cauline leaves); blade 1-veined, oblanceolate to spatulate (proximal leaves) or elliptic to ovate (cauline leaves), somewhat succulent, apex acute. Inflorescences terminal, umbellate cymes, sometimes not yet developed in young individuals, then with 2–4 bracts and often buds at base of pedicel; bracts clustered, foliaceous with scarious margins to entirely scarious. Pedicels reflexed after flowering, erect in fruit. Flowers bisexual or occasionally unisexual and pistillate; perianth and androecium hypogynous; sepals 5, distinct, green, lanceolate to ovate, 2.5–4.5 mm, herbaceous, margins white, scarious, apex acute to obtuse, not hooded; petals 5, white to pink, clawed, blade apex jagged but not 2-fid; nectaries not apparent; stamens 3–5, arising from base of ovary; filaments distinct nearly to base; staminodes absent; styles 3(–5), clavate to filiform, 0.5–1.5 mm, glabrous proximally; stigmas 3(–5), subterminal to linear along adaxial surface of styles, minutely papillate (50×). Capsules ovoid to cylindric, opening by 6 (rarely 8 or 10) revolute teeth; carpophore absent. Seeds 35–60, orange to brown, oblong, shield-shaped, dorsiventrally compressed, papillate, marginal wing absent, appendage absent; embryo central, straight. x = 10.

Distribution

Introduced; Europe (e Mediterranean region), c, sw Asia, Africa (Mediterranean region, s to Ethiopia), introduced in South America (Argentina), w Europe, Africa (Republic of South Africa).

Discussion

Species 3–4 (1 in the flora).

Selected References

Shinners, L. H. 1965. Holosteum umbellatum (Caryophyllaceae) in the United States: Population explosion and fractionated suicide. Sida 2: 119–128.

Lower Taxa

Holosteum umbellatum