The lush vegetation of Big Morongo Canyon stands in sharp contrast to the surrounding desert slopes. A high water table in the canyon has made the growth of tall trees possible, despite the desert climate. The desert springs ecosystem and Mojave Riparian Forest here are considered to be some of the best in California. In addition, the area is of botanical interest because it includes two desert vegetation zones: the Mojave and the Sonoran. Dry slopes are characterized by low creosote bush scrub. The Preserve offers food, cover and water to many resident birds, and shelters many migrant and vagrant species.
Download a Complete Index of the Flora of the Preserve (Updated February 2024)
Plant Communities
Big Morongo Canyon Preserve is host to a remarkable variety of plant communities:
Mojave Riparian (streamside) Forest
The Mojave Riparian Forest, which marks the course of the marshes and streams through the canyon, is formed by stands of cottonwood trees, willows, alders and mesquite.
Each tree is uniquely adapted to survive: The mesquite has very deep roots for obtaining water; the cottonwood has fluttering leaves for capturing sunlight even down to the innermost layers of leaves; the willow has an extensive root system that allows it to colonize riparian areas more quickly than other streamside trees; the alder grows faster and taller in order to overshadow the canopy of other shade-makers.
Fresh-water Marsh
Fresh-water Marsh occurs where water comes to the surface in flowing streams or boggy areas. Major plants that love this environment include cattail, rushes, sedges, watercress, water-parsnip, etc.
Desert Wash
Desert Wash occurs in dry streambeds where water flows only intermittantly after rain. Major plants found here include catalpa, catsclaw, rabbitbrush, baccharis, etc.
Creosote Bush Scrub
Creosote Bush Scrub occupies most of the flats and slopes of Morongo Valley. Some conspicuous plants here are creosote, Mojave Yucca and juniper, bushy perennials and annual flowers. The limiting growth factor of plants here is water, and consequently the leaves of most of these plants are small to reduce water loss.
Open Fields
Open fields occur in the Preserve where native vegetation has been removed in the past for grazing land.
When disturbed land like this is allowed to recover and revegetate naturally, a predictable succession of plants will move in. If left undisturbed, the old fields would probably return to creosote bush scrub, except for the fact that the area is increasingly wetter and wetter, so it may even become pockets of fresh water marsh surounded by riparian woodland.
Conspicuous Plants Along the Trails
Marsh Trail
Fremont Cottonwood
Honey Mesquite
Southern Cattail
Olney Bulrush
Stinging Nettle
Red Willow
Slender Willow
Yerba Mansa
Mexican Wire Rush
Saltgrass
Datura (Jimson Weed)
Willows (4 species)
Clematis
Iris-leaved Rush
Watercress
Baccharis
Water Parsnip
Desert Willow Trail
Desert Catalpa (Desert Willow)
Honey Mesquite
Creosote Bush
Wild Rhubarb
Alkali Goldenbush
Anderson’s Thornbush
Yerba Santa
Thorny-fruited Cholla
Mojave Yucca
Mesquite Trail
Honey Mesquite
Clematis
Dogbane
Wild Cucumber
Yerba Mansa
Mojave Yucca
Celery
Desert Fan Palm
Fremont Cottonwood
Honey Mesquite
Poverty Weed
Meadow Fescue
Goldenrod
Yucca Ridge Trail
Mojave Yucca
Bladder Pod
Paper-bag Bush
California Buckwheat
Creosote Bush
Live-forever
Desert Trumpet
Mormon Tea (Joint Fir)
Anderson’s Thornbush
Wingscale (Hoary Saltbush)
Calico Cactus (Engelman’s Hedgehog)
Parry’s Cloak Fern
Canyon Trail
Arrowweed
Saltgrass
Honey Mesquite
Five-hook Bassia
Yerba Santa
Alkali Goldenbush
Mule Fat