Prenanthella is a monotypic genus of flowering plants in the family Asteraceae.^[1] It contains the single species Prenanthella exigua, which is known by the common name brightwhite.^[2] It is native to the southwestern United States from California to Texas and it is known as far north as Idaho. Its habitat includes desert and woodlands. This annual herb produces a slender, branching stem reaching a maximum height near 40 centimeters. It has a sparse coating of glandular hairs and contains a milky juice. Most of the leaves are located near the base of the stem. They are widely lance-shaped and sometimes divided into segments. Smaller leaves occur higher on the stem; these may be reduced to scale-like structures, leaving the stem mostly bare. The inflorescence is a wide open panicle of several flower heads. Each small head is cylindrical and narrow, its base wrapped in lance-shaped phyllaries. At the tip of the head bloom 3 or 4 flowers, which are ray florets; there are no disc florets. Each floret has is white to pale pink and has a toothed tip. The fruit is a white achene with a pappus of white bristles.

Prenanthella
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Asterales
Family:	Asteraceae
Subfamily:	Cichorioideae
Tribe:	Cichorieae
Subtribe:	Microseridinae
Genus:	Prenanthella Rydb.
Species:	P. exigua
Binomial name
Prenanthella exigua (A.Gray) Rydb.
Synonyms
Lygodesmia exigua