Acamptopappus is a small genus of flowering plants in the family Asteraceae (daisy family), formally described in 1873. It contains just two species of low-growing desert shrubs, both native to the arid landscapes of the Mojave and Great Basin deserts of southwestern North America. The genus is commonly known as goldenheads, a reference to the yellow, button-like flowerheads characteristic of both species.
The two members of the genus — A. sphaerocephalus (Rayless Goldenhead) and A. shockleyi (Shockley's Goldenhead) — are found across California, Nevada, Utah, and Arizona, growing in dry, sandy, or rocky desert soils. The genus name reflects a notable botanical feature: the pappus (the modified calyx that aids in seed dispersal) is straight and unbent, from the Greek a- (not) and campto- (bent).
Ecologically, Acamptopappus serves as a larval host plant for the moth Coleophora acamtopappi, which feeds specifically on A. sphaerocephalus.
Etymology
The name Acamptopappus derives from the Greek elements a- (not), campto- (bent), and pappus (down or feathery bristle), referring to the unbent, straight pappus of the seed heads. The plants are colloquially known as goldenheads, after their rounded yellow flowerheads.
Distribution
Acamptopappus is native to the desert regions of southwestern North America. A. shockleyi is found in California and Nevada, while A. sphaerocephalus has a wider range spanning California, Nevada, Utah, and Arizona. Both species are characteristic of Mojave Desert and Great Basin Desert habitats.
Ecology
The larvae of the moth Coleophora acamtopappi (Lepidoptera: Coleophoridae) feed on Acamptopappus sphaerocephalus, making this desert shrub a specific larval host plant in its arid ecosystem.
