Proc. Amer. Acad. Arts7: 356. 1868
sw United States.
Species 3 (3 in the flora).
See discussion of Filagininae following tribal description (p. 385).
Hesperevax is known from sites in Mediterranean climates of western California and southwestern Oregon. Most of its taxa grow in distinctive habitats, where they tolerate or exploit moderate levels of disturbance.
Hesperevax is monophyletic and probably sister to Ancistrocarphus; Gifolaria (Cosson & Kralik) Pomel may also be related (J. D. Morefield 1992). Hesperevax is sharply distinct from Evax and relatives by receptacles bristly (unique in Filagininae), staminate paleae enlarged, thickened, apices erect or spreading, blunt, adaxially green and lanuginose, and staminate corollas zygomorphic (Morefield 1992c). The species are relatively easy to distinguish by the sizes, shapes, and arrangements of leaves, glomerules, and heads.
|1||Terminal heads in loose glomerules of 3–5, cylindric, heights 1.8–2.5 times diams.; capitular leaves 1–4 per glomerule or head; staminate paleae: apices ± erect||Hesperevax sparsiflora|
|1||Terminal heads borne singly or in dense glomerules of (2–)10–40+, campanulate or ± obpyramidal, heights 1–1.5 times diams.; capitular leaves 6–20 per glomerule or head; staminate paleae: apices spreading||> 2|
|2||Largest leaves 4–22(–32) × 0.5–4(–5) mm; petiole lengths 0–1.5 times blade lengths, bases scarcely thickened, pliant to ± cartilaginous; heads borne singly or, rarely, in glomerules (3–7 mm diam.) of 2–8 mixed with leaves||Hesperevax acaulis|
|2||Largest leaves (25–)33–90 × 7–20 mm; petiole lengths 2–3 times blade lengths, bases thickened, indurate; heads in glomerules (10–25 mm diam.) of 10–40+ not mixed with leaves||Hesperevax caulescens|
|Author||James D. Morefield +|
|Basionym||Evax Hesperevax +|
|Etymology||Greek hesperos, western, and genus name Evax, alluding to first discoveries from western limits of Evax distribution +|
|Taxon name||Hesperevax +|
|Taxon parent||Asteraceae tribe Gnaphalieae +|
|Taxon rank||genus +|
|Volume||Volume 19 +|