Lasthenia sect. Amphiachaenia
Madroño 48: 205. 2002.
Annuals or perennials. Leaves entire or ± toothed. Involucres campanulate to depressed-hemispheric, hemispheric, or obconic. Phyllaries ± persistent or falling with cypselae, distinct. Receptacles narrowly conic to conic (subulate in L. leptalea), muricate or papillate, glabrous. Ray corollas bright-yellow, laminae 2.5–16 mm, floral pigments turning deep red in dilute aqueous alkali. Disc corolla lobes 5; anther appendages deltate to sublanceolate or subulate (broadened distal to bases); style apices ± deltate with apical tufts of hairs and subapical fringes of shorter hairs. Cypselae to 4 mm; epappose or pappose. 2n = 16, 32, 48.
w United States, nw Mexico
Species 4 (4 in the flora).
Perennial lasthenias are found only in sect. Amphiachaenia. Epappose plants of sect. Amphiachaenia are more likely to be found in coastal populations and may constitute entire local populations.
|1||Stems glabrous proximally, villous distally; phyllaries usually 4–6, glabrous but for apices; receptacles subulate, papillate; anther appendages subulate; interior w California||Lasthenia leptalea|
|1||Stems ± hairy throughout, sometimes more so distally; phyllaries 4–16, hairy; receptacles conic, muricate; anther appendages deltate to sublanceolate; Arizona, California, Oregon||> 2|
|2||Perennials; coastal Oregon||Lasthenia ornduffii|
|2||Annuals or perennials; coastal or inland Arizona, California, Oregon||> 3|
|3||Annuals; leaves entire; pappi usually of (2–)4(–6) opaque, white (aging to brown), ovate-lanceolate, aristate scales, sometimes 0; Arizona, California (includingChannel Islands)||Lasthenia gracilis|
|3||Annuals or perennials (if perennial, only in coastal California); leaves entire or with 3–5+ teeth; pappi 0, or of 1–7 translucent (rarely opaque), brown (rarely white), linear to subulate, aristate scales; n California, s Oregon||Lasthenia californica|