About Hesperevax sparsiflora (A.Gray) Greene
Hesperevax sparsiflora (A.Gray) Greene is a species of flowering plant in the family Asteraceae, commonly known by the common name erect dwarf cudweed. It is native to California and Oregon, where it grows in multiple habitat types, including sandy coastal areas and the serpentine soils of inland hills. This is a small woolly annual herb, reaching a maximum height of less than 18 centimeters. It produces oval, rounded, or scoop-shaped leaves borne on short petioles, and leaf morphology varies across the species' two varieties. Small flower heads grow between the leaves, and these heads contain greenish or whitish disc florets. Each individual floret is remarkably small, measuring only 0.2 millimeters (1/120th of an inch) wide. A whole disc, including its bracts, contains 5 to 9 florets and totals just 3.8 millimeters (1/6th of an inch) wide. This makes Hesperevax sparsiflora the holder of the world's smallest composite inflorescence. Two varieties are recognized: Hesperevax sparsiflora var. brevifolia, commonly called short-leaved evax, is an uncommon coastal variety that generally has leaves under one centimeter long. Hesperevax sparsiflora var. sparsiflora is a longer-leaved variety that is more common, but is limited exclusively to California.
