Geraea

Torrey & A. Gray

Proc. Amer. Acad. Arts 1: 48. 1847.

Common names: Desert-sunflower
Etymology: Greek geraios, old, alluding to white-haired involucre of Geraea canescens
Treatment appears in FNA Volume 21. Treatment on page 122. Mentioned on page 65, 66, 119.

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.

Distribution

sw United States, nw Mexico.

Discussion

Species 2 (2 in the flora).

Selected References

None.

Key

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 Geraea canescens
1 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 Geraea viscida
... more about "Geraea"
Curtis Clark +
Torrey & A. Gray +
Desert-sunflower +
sw United States +  and nw Mexico. +
Greek geraios, old, alluding to white-haired involucre of Geraea canescens +
Proc. Amer. Acad. Arts +
Undefined (tribe Undefined) subtribe Enceliinae +, Undefined (tribe Undefined) subtribe Engelmanniinae +, Undefined (tribe Undefined) subtribe Spilanthinae +, Undefined (tribe Undefined) subtribe Verbesininae +  and Undefined (tribe Undefined) subtribe Zinniinae +
Asteraceae (tribe Heliantheae) subtribe Ecliptinae +