Acamptopappus sphaerocephalus, Rayless Goldenhead
Scientific Name: Acamptopappus sphaerocephalus
Common Name: Rayless Goldenhead
Also Called: Goldenhead
Family: Asteraceae, Sunflower Family
Size: Up to 3 feet tall, more or less.
Growth Form: Shrub, subshrub; low branching; ascending and erect; mostly glabrous (note; variety "hirtellus"; has small dense hairs); gray or whitish bark, bark becomes shredded with age, new growth green.
Leaves: Green; small, alternate, entire; spatulate, linear or lanceolate, lower leaves fascicled or clustered.
Flower Color: Yellow; inflorescence a cyme; floral heads generally in loose, rounded to flat-topped clusters; medium sized flower heads; disk or "discoid" flowers only, 13 to many florets per head with yellow corollas; flower heads spheric or globose, single or usually clustered heads on short pedicels located on tips of new growth; pappus light to brownish bristles; fruit an achene tipped with thick scales and also with bristles.
Flowering Season: April to October.
Elevation: 1,000 to 4,500 feet in Arizona; 200 to 7,250 feet California.
Habitat Preferences: Upper desert areas, pinyon-juniper communities, mountain slopes, open flats or dry plains, mesas, rocky areas and gravelly soil.
Plant associations include; Catclaw Acacia (Acacia greggii), California Juniper (Juniperus californica), Scrub Oak (Quercus turbinella), Joshua Tree (Yucca brevifolia), California Buckwheat (Eriogonum fasciculatum), Golden Cholla (Opuntia echinocarpa), and Mojave Yucca (Yucca schidigera).
Recorded Range: A southwestern species in the United States, Rayless Goldenhead is found in AZ, CA, NV and UT. In Arizona, it occurs in the western half of the state and also in Graham County.
North America & US County Distribution Map for Acamptopappus sphaerocephalus.
U.S. Weed Information: No data available.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: No data available.
Threatened/Endangered Information: No data available.
Genus Information: In North America there are 2 species and 4 accepted taxa overall for Acamptopappus. Worldwide, The Plant List includes 2 accepted species names with 1 infraspecific rank for the genus.
In the Southwestern United States, in Arizona and Utah there is 1 species of Acamptopappus, in California and Nevada there are 2 species, New Mexico and Texas have 0 species. All data is approximate and subject to taxonomic changes.
There are 2 varieties in Acamptopappus sphaerocephalus;
Acamptopappus sphaerocephalus var. hirtellus, Rayless Goldenhead (AZ, CA, NV);
Acamptopappus sphaerocephalus var. sphaerocephalus, Rayless Goldenhead (AZ, CA, NV, UT).
Comments: Rayless Goldenhead is a southwestern species with a tendency or partiality of the majority of its populations toward the western geographic area of the Mojave Desert and some species extend north into the Great Basin Desert. Thus, Rayless Goldenhead is found in the Sonoran, Mojave and Great Basin Deserts.
For a comprehensive thoroughly documented review of Acamptopappus sphaerocephalus see the USDA; USFS Fire Effects Information System, or FEIS.