Pseudostellaria

Herbs, perennial. Taproots absent, rhizomes usually with spherical or elongate, tuberous thickenings or vertical fleshy roots, rooting at nodes. Stems ascending to erect, simple or branched, terete or 4-angled. Leaves connate proximally into sheath, sessile; blade 1-veined, linear to lanceolate or elliptic, not succulent, apex acute. Inflorescences terminal, open cymes, or flowers solitary; bracts paired, smaller, herbaceous or scarious. Pedicels recurved to reflexed from base or abruptly bent downward near distal end in fruit. Flowers: perianth and androecium hypogynous; sepals 5, distinct, green, narrowly ovate to lanceolate, 3–7 mm, herbaceous, margins white, scarious, apex obtuse or acute to acuminate, not hooded; petals 5 [absent in cleistogamous flowers], white, not clawed, blade apex 2-fid to V-shaped notch 1/10–1/5 of length; nectaries adnate to base of filaments opposite sepals, circular, thickened, 2–21/2 times filament width; stamens 5 or 10, arising from base of ovary; filaments distinct; styles 3, capitate to clavate, 2–4.5 mm, glabrous proximally; stigmas 3, terminal or linear along adaxial surface of styles, minutely papillate (30×). Capsules ovoid, opening by 6, ± 2–3 times recoiled valves; carpophore absent. Seeds 1–3, red-brown or brown, circular to oblong or elliptic, plump or laterally compressed, tuberculate, marginal wing absent, appendage absent. x = 8.

Distribution

w United States, se Europe, e Asia.

Discussion

Species 21 (3 in the flora).

We follow W. A. Weber and R. L. Hartman (1979) in recognizing Pseudostellaria in North America. The combination of a V-shaped petal sinus cut to only 1/10–1/5 of the petal length, often tuberous rhizomes and thickened roots, and the more or less recoiled capsule valves segregates our species from Stellaria. The relationship between the North American and Asian species requires further investigation. While the seeds of P. sierrae and P. oxyphylla closely resemble those of P. rupestris (Turczaninow) Pax, the type species, the presence of five (rather than ten) stamens, absence of tubers, and absence of cleistogamous flowers complicate placing our species in the current infrageneric classification (M. Mizushina 1965).

Selected References

None.

Lower Taxa

Pseudostellaria jamesiana, Pseudostellaria oxyphylla, Pseudostellaria sierrae

Key

1	Pedicels and sepals uniformly stipitate-glandular, often densely so; anthers 10, purple	Pseudostellaria jamesiana
1	Pedicels glabrous or with narrow internodal line of hairs; sepals glabrous or with margins ciliolate in proximal 2; anthers 5, yellow	> 2
2	Stems and pedicels each with narrow internodal line of hairs; leaf blades 6-12 cm; inflorescences with flowers paired (single by abortion), pedicellate, in distal 3-7 axils or in terminal cymes	Pseudostellaria oxyphylla
2	Stems and pedicels glabrous; leaf blades 0.7-3.5 cm; inflorescences with flowers solitary, terminal, sometimes on 1-2 axillary branches	Pseudostellaria sierrae