This week, a heavy sweet scent fills the air in the Wenatchee Foothills. The fragrance is wafting from masses of small bright yellow blossoms covering antelope bitterbrush (Purshia tridentata) shrubs. Often over 100 years old, these deciduous native shrubs grow in shrub-steppe, dry forests, and on rocky ridge tops throughout the arid western U.S.
This species has a long tap root – up to 15-18 feet- and shallow laterally spreading roots. Two kinds of roots provide access to both groundwater and seasonal precipitation. The spreading leafy canopy offers a cool shady microhabitat where native wildflowers thrive and lizards and snakes find thermal refuge. Each shrub produces abundant large shiny brown seeds. Harvester ants are major seed predators.
The most important seed predators are rodents like deer mice and montane voles who harvest and cache large percentages of a shrub’s seed crop. Caches are 1-2 inches deep and tend to be in soils without leafy litter on top. Rodents return to eat the stored seeds, but some are left to sprout the next spring.
Mice and voles then come nibble on the nutritious newly sprouted seedlings. When this grazing is incomplete, several seedlings can continue growing to form the future seed-producing shrubs. Read more about bitterbrush seed caches here.
Next time you head out for a walk in the Wenatchee foothills, take along a a notebook and pencil so you can make a sketch of a trailside blooming antelope bitterbrush. Be sure to take a look at the small leaves. Examine both surfaces and the shape of each wedge-shaped leaf with a 3-toothed tip. The upper leaf surface is bright green with scattered hairs and the lower surface is densely wooly and paler green.
Sketching focuses your brain to really look at details about the leaf, flower, stems, and overall growth form.
Curious readers who want to explore other common shrubs can use my photo field guide here. Read how mule deer rely on shrubs like antelope bitterbrush as a nutritious winter browse food here. Learners of all ages can learn more about antelope bitterbrush’s important role in our shrub-steppe ecosystems using curricula posted on this website under the TEACHER Tab, here:
Teaching about Shrub-steppe, Wildlife, & Plants
USFS Celebrating Wildflowers Just for Kids Webpage, with Native Wildflower Coloring Sheets and Wildflower Ethics
SagebrushEcosystem_Encyclopedia Life History narratives with photos and range maps for 40 animals and plants. Text includes adaptions to a fire adapted ecosystem.
USFS Fireworks Curriculum Featuring the Sagebrush Ecosystem (Grades 6-8th). Aims to increase understanding of the physical science of combustion, biodiversity, fire as a natural ecosystem component, and the influence of people. Aligned to national standards.
BLM_ID_SagebrushSteppeCards_2017_lowres . Sagebrush-steppe species photo cards developed by the B.L.M. Includes plants and animals with line drawings and natural history facts on the backside.
Shrub-steppe food chain species cards– Artist-created flash-cards with native animals and plants of Washington’s shrub-steppe ecosystems.
Shrub-steppe_Habitat_Cards A set of photos and text for a selection of plant and animal species of the intermountain west shrub-steppe ecosystems.
Western U.S. Habitat Flashcards . Sets of wildlife photo cards for different habitats including Sagebrush-steppe, Mountains, Conifer Forests, Deciduous Forests, Mountains, Riparian Habitat, Shortgrass Prairie, Wetlands, and Schoolyard.
I am really enjoying seeing them bloom this year!