Leptosiphon aureus

Leptosiphon aureus (a.k.a. Leptosiphon chrysanthus ) is a species of flowering plant in the phlox family known by the common name golden linanthus.

Description
Golden linanthus is an annual herb producing a thin, threadlike stem with occasional leaves divided into narrow needlelike lobes. The oppositely arranged leaves are each divided into very narrow bristlelike lobes up to a centimeter long.

The tip of the stem has an inflorescence of usually a single flower with corolla lobes under a centimeter long. The nominate subspecies generally has bright to golden yellow flowers, while ssp. decorus has white or cream blooms. The bloom period is March to June.

Subspecies
The two subspecies overlap in geography but do not occur together.
 * Leptosiphon aureus ssp. aureus (Leptosiphon chrysanthus ssp. chrysanthus) — pinyon-juniper woodlands, madrean pine-oak woodlands in Madrean Sky Islands, and desert flats.
 * Leptosiphon aureus subsp. decorus (Leptosiphon chrysanthus ssp. decorus) — endemic to the Mojave Desert in California.

Distribution and habitat
The plant is native to the Southwestern United States in Arizona, Nevada, New Mexico, and Southern California; and to northwestern Mexico in Baja California state.

It grows in desert flats and desert chaparral of the Mojave Desert and Sonoran Desert; in chaparral and woodlands of the Peninsular Ranges and Transverse Ranges; and in pinyon-juniper woodlands and madrean pine-oak woodlands of Madrean Sky Islands.