Lasthenia sect. Lasthenia

Annuals. Leaves entire. Involucres hemispheric to obconic. Phyllaries persistent, connate 2/3+ their lengths. Receptacles conic, papillate, glabrous. Ray corollas yellow, laminae (0–)0.5–2 mm, floral pigments remaining yellow in dilute aqueous alkali. Disc corolla lobes 4(–5); anther appendages oblong or obovate; style apices ± deltate, glabrous or glabrate. Cypselae to 4 mm; pappose. 2n = 10.

Distribution

w North America, South America (Chile).

Discussion

Species 2 (1 in the flora).

Section Lasthenia has an amphitropical distribution: L. glaberrima ranges from southwestern Washington to central California; L. kunthii Hooker & Arnott is known only from central Chile (P. H. Raven 1963c). The species are very similar morphologically, and conclusive identification of specimens sometimes is difficult without knowing where the plant was collected. Both L. glaberrima and L. kunthii are self-pollinating and are found in vernal pools or other seasonally wet habitats.

Selected References

None.

Lower Taxa

Lasthenia glaberrima