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 | |
References
edit- ^ Ford, V. S., et al. (2006). Species divergence and relationships in Stephanomeria (Compositae): PgiC phylogeny compared to prior biosystematic studies. American Journal of Botany 93: 480-90.
- ^ USDA Plants Profile