Stephanomeria diegensis

Stephanomeria diegensis is a species of flowering plant in the aster family known by the common name San Diego wirelettuce.[1] It is native to the coastal hills and ranges of southern California and Baja California, where it grows in many types of open habitat. It evolved as a hybrid of Stephanomeria exigua and S. virgata.[2] Furthermore, it is thought to be the result of homoploid hybrid speciation, which is uncommon.[3] The plant is frequently misidentified as one of its parents, especially if older taxonomic keys are used.[4] This is an erect annual herb easily exceeding two meters in height. Its slender stem has many spreading branches. The basal leaves are linear to lance-shaped and up to 10 centimeters long. The leaves wither early and are absent for most of the year, giving the plant a twiglike appearance. Leaves on the upper stem are small and reduced. The inflorescences are usually clusters of flower heads located at intervals on the stiff branches. Each head has a cylindrical base lined with phyllaries. These are often glandular. The head contains several ray florets, each with an elongated tube and a white or pink-tinged ligule measuring around a centimeter long. The fruit is a grooved achene tipped with a spreading cluster of long, plumelike pappus bristles.

Stephanomeria diegensis
Scientific classification
Kingdom:
Plantae
(unranked):
Angiosperms
(unranked):
Eudicots
(unranked):
Asterids
Order:
Asterales
Family:
Asteraceae
Tribe:
Cichorieae
Subtribe:
Microseridinae
Genus:
Stephanomeria
Species:
S. diegensis
Binomial name
Stephanomeria diegensis
Gottlieb

References
  1. "Stephanomeria diegensis". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 2 December 2015.
  2. Gallez, G. P. and L. D. Gottlieb. (1982). Genetic evidence for the hybrid origin of the diploid plant Stephanomeria diegensis. Evolution 36:6 1158-67.
  3. Sherman, N. A. & J. M. Burke. (2009). Population genetic analysis reveals a homoploid hybrid origin of Stephanomeria diegensis (Asteraceae). Mol Ecol 18:19 4049-60.
  4. Chester, T. S. diegensis: An analysis


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