Growth Form:Shrub; shrubby stiff habit; stems erect, brittle, rough to the touch (scabrous), circular in cross section, usually without grooves or ridges (terete); bark gray.
Leaves: Green or silvery; leaves arranged alternately along stems; leaves without supporting stem (sessile); leathery to fleshy; leaf surfaces are smooth (glabrous) and secrete a viscid substance (resinous); blades vary from linear to lanceolate or spatulate.
Flowering Season: April, May or June to September, October or November.
Elevation: 1,000 to 6,500 feet (300-2,000 m).
Habitat Preferences: Dry canyons, roadsides, open oak woodlands and grasslands.
Recorded Range: Baccharis pteronioides is found in the Chihuahuan and Sonoran deserts in the southwestern United States in AZ, NM and western Texas. It is also native and widespread throughout most of Mexico. In Arizona it is found in the central and eastern ⅔ and northwest parts of the state.
Species distribution map for Baccharis pteronioides:
Range map courtesy of Virginia Tech, Department of Forest Resources & Environmental Conservation
Click image for full size map
Genus Information: In North America there are 24 species and 26 accepted taxa overall for Baccharis. World wide, The Plant List includes 430 accepted species names and includes a further 409 scientific plant names of infraspecific rank for the genus.
In the Southwestern United States: Arizona and California each have 10 species of Baccharis, Nevada has 5 species, New Mexico has 13 species, Texas has 12 species, Utah has 5 species. All data is approximate and subject to taxonomic changes.
Comments: Yerba de Pasmo is not as large as other species of Baccharis. According to Arizona Flora, and Flora of North America, Baccharis pteronioides is reputed to be poisonous to livestock.
Seeds of Baccharis pteronioides may likely be eaten by birds and small mammals. However Baccharis pteronioides is reputed to be poisonous to livestock.
Special Value to Native Bees, Butterflies and Insects
Yerba de Pasmo, Baccharis pteronioides, may attract insects including butterflies and possibly bees and other small insects.
Etymology:
The etymology of the genus Baccharis (Bac'charis:) is uncertain and possibly named after Bacchus (Dionysus), the Greek god of fertility, wine, revelry and sacred drama.
The species epithet "pteronioides" is from Ancient Greek "ptero" or "pteron" meaning wing or feather and also from Ancient Greek "-oid", "-oide" "-oidés" meaning of similar form to, but not the same as, having the likeness of.
Ethnobotany
Baccharis pteronioides, Yerba de Pasmo has been used as an external antirheumatic and venereal aid by southwestern United States indigenous peoples.
Yavapai Drug, Antirheumatic (External), Decoction of leaves and roots used as wash for rheumatism.
Yavapai Drug, Venereal Aid, Decoction of leaves and roots used as wash for gonorrhea.
See ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.