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FNA | Family List | FNA Vol. 21 | Asteraceae

283. Geraea Torrey & A. Gray, Proc. Amer. Acad. Arts. 1: 48. 1847.

Desert-sunflower [Greek geraios, old, alluding to white-haired involucre of Geraea canescens]

Curtis Clark

Annuals or perennials, 10–100 cm. Stems erect, branched (branches ascending). Leaves basal and cauline; alternate; sessile or petiolate; blades (3-nerved) elliptic, lanceolate, oblanceolate, oblong, or ovate, bases auriculate or tapering, margins entire or toothed, faces ± canescent or glandular-puberulent to stipitate-glandular. Heads radiate or discoid, borne singly or in open, paniculiform arrays (peduncles usually longer than involucres). Involucres hemispheric, 7–15 mm diam. Phyllaries persistent, 20–30+ in 2–3+ series (distinct, narrowly lanceolate to linear or narrowly lance-oblong to lance-ovate, subequal to unequal, outer shorter). Receptacles convex, paleate (paleae ± conduplicate, folded around and falling with cypselae). Ray florets 0 or 10–21, neuter; corollas yellow. Disc florets 60–200+, bisexual, fertile; corollas yellow, tubes shorter than gradually to abruptly expanded throats, lobes 5, triangular. Cypselae (black) strongly compressed, narrowly cuneate (margins ± white, long-ciliate, faces ± hairy); pappi persistent, of 2 awns or subulate scales. x = 18.

Species 2 (2 in the flora): sw United States, nw Mexico.

1 Annuals; leaves sessile or petiolate, bases of blades tapering to wings, faces ± canescent; phyllaries narrowly lanceolate to linear, apices acute (margins shaggy-ciliate); ray florets 10–21   1 Geraea canescens
+ Perennials; leaves sessile, bases of blades ± auriculate, faces glandular-puberulent; phyllaries narrowly lance-oblong to lance-ovate, apices obtuse (faces densely glandular-puberulent); ray florets 0   2 Geraea viscida

Lower Taxa


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