Growth Form:Forb/herb; stems generally green, upright, slender branching on upper stems; stems may be smooth or with small hairs.
Leaves: Green; leaves are divided into narrow or linearlobes; leaves smooth or having short soft hairs.
Flower Color: Cream to white, yellow or bright yellow; flower heads small; diskflorets only, no rayflorets; bracts surrounding flower heads are generally linear; the anthers arising from the middle of the floret are brown or yellow; the fruit is a cypsela.
Flowering Season: June or July to October, summer and fall after monsoon rainfall.
Elevation: 3,500 to 7,000 feet (1,067-2,134 m); below 1,000 feet (305 m) in California
Habitat Preferences:Mesas, plains and disturbed sites especially along roadsides.
Recorded Range: Rare in the United States found only in AZ, CA and NV. Also native to northern Mexico. In the southwest it is found primarily in Arizona with small populations in southeast Nevada and southern California. In Arizona it occurs in the central (Maricopa, Co.) and northwestern parts of the state. Loomis' Thimblehead is also native to central Mexico in the Sierra Madre Occidental in western Chihuahua.
North America species range map for Thimblehead, Hymenothrix loomisii:
North American range map courtesy of Virginia Tech, Dept. of Forest Resources & Environmental Conservation
Click image for full size map
Genus Information: In North America there are 3 species and 3 accepted taxa overall for Hymenothrix. Worldwide, The Plant List includes 6 accepted species names and a further 10 scientific names of infraspecific rank for the genus.
In the Southwestern United States: Arizona has 3 species of Hymenothrix, California, New Mexico and Texas each have 2 species, Nevada has 1 species and Utah has 0 species. Data approximate and subject to revision.
Comments: Loomis’ Thimblehead is similar in appearance to Trans-Pecos Thimblehead, Hymenothrix wislizeni, and Wright's Thimblehead, Hymenothrix wrightii. However, there are clear visible differences between all three in the flowers; Trans-Pecos Thimblehead is the only species with rayflorets while Loomis' and Wright's Thimblehead only have diskflorets and Loomis' flowers are cream, whitish or yellow while Wright's flowers are white or pinkish.
Loomis' Thimblehead, Hymenothrix loomisii flowers, seeds and plants may be visited, eaten and used by hummingbirds and/or small mammals including rodents in search of food, nectar, shelter and protection through cover.
Beneficial Value to Butterflies, Bees and Insects
Loomis' Thimblehead, Hymenothrix loomisii, with their brightly colored flowers, may be visited by butterflies, moths and other insects in search of food.
Etymology:
The genus “Hymenothrix” (Hymeno'thrix:) from the Greek hymen, “membrane,” and thrix, “bristle,” referring to the pappus.
