Lasthenia sect. Hologymne
Trans. Amer. Philos. Soc., n. s. 7: 383. 1841.
Annuals. Leaves entire (blades ± fleshy, bases sometimes connate and sheathing). Involucres hemispheric. Phyllaries persistent, connate 2/3+ their lengths (forming cups, glabrous but for distinct apices). Receptacles ± conic, papillate or warty, glabrous or sparsely hairy. Ray corollas yellow, laminae 4–14 mm, floral pigments remaining yellow in dilute aqueous alkali. Disc corolla lobes 5; anther appendages deltate or broadly ovate; style apices deltate with apical tufts of hairs and subapical fringes of shorter hairs. Cypselae 2–3.5 mm; epappose. 2n = 14.
Species 3 (3 in the flora).
Members of sect. Hologymne have a high salt tolerance and usually occur in moderately to strongly alkaline habitats, such as coastal salt marshes, around vernal pools, and in wet areas around alkali flats (i.e., hard-packed, poorly aerated, saline clays). The herbage of these plants also becomes succulent in response to increasing soil salinity as the soil dries up. All three species show a narrow range of morphologic characteristics except for their variable cypselae.
|1||Cypselae black, strongly flattened, obovoid, margins ciliate (hairs stiff, blunt), faces glabrous or scabrous||Lasthenia chrysantha|
|1||Cypselae black, ± flattened and obovate to oblong, or gray, ± clavate or obovoid, margins sometimes ciliate, faces glabrous or hairy (sometimes papillate)||> 2|
|2||Cypselae ± flattened and obovate to oblong, to 2.5 mm, faces ± hairy (hairs curved) and papillate||Lasthenia ferrisiae|
|2||Cypselae ± clavate or obovoid, to 3.5 mm, faces glabrous or hairy and papillate (papil-lae rusty or yellowish, wartlike)||Lasthenia glabrata|