Barker Dam Loop

Color photo taken from above the Barker Dam area of a panoramic view at sunset. Water, piles of rocks, and some vegetation fill the area. Photo: NPS / Hannah Schwalbe
Sunset over Barker Dam area.

NPS / Hannah Schwalbe

This trail is an easy 1.1 mile loop with minimal elevation gain. The presence of standing water brings a unique set of freshwater indicator species to this trail, which you see in and around Barker Dam. The trail winds through bouldery outcrops with pinyon-oak woodlands, desert willow riparian corridors, and loamy basins dominated by Joshua tree woodlands or creosote bush scrub.
Color image of a map of the Barker Dam area. The trail leaves from a parking lot in the lower right, and makes a loop headed north, then west, south, and back east to meet partway up the first part of the trail. The trail looks like it makes a 9 in shape.

Area Map

Section 1

Color photo of a small white flower surrounded by green foliage.

Desert Tobacco

Nicotiana obtusifolia

This plant is a member of the Solanaceae family, which also includes tomatoes, potatoes, and eggplant. Give it a sniff! Many members of this family contain alkaloids, such as nicotine. These chemical compounds discourage herbivory and give the plant a distinct fragrance. Desert tobacco is in the same genus as commercially produced tobacco (N. tabacum) and, like that plant, was traditionally smoked by Native Americans, to whom tobacco was sacred rather than recreational.
Color photo of a bunch of star-shaped white flowers with blue-purple tinge on the tips.

Woolly Bluestar

Amsonia tomentosa

The species name tomentosa refers to the matted and intertwined hairs you may see on some of these plants. Curiously, this species may have individuals that are completely covered in hairs, appearing grayish-white in color, while other individuals growing directly adjacent can be completely green and hairless. Some individuals even have both forms growing on the same plant!
Color photo of a tall green stalk with 5 offshoots with little purple flowers and a small bunch of purple buds at the top. Photo: Michelle Cloud-Hughes

Michelle Cloud-Hughes

Perennial Rockcress

Boechera perennans

As its name indicates, you will often find the perennial rockcress in rugged habitats such as the gaps between stones. The flower has four pink petals with four long and two short stamens. This trait, along with a bean-like fruit known as a silique, helps to place this species in the mustard family (Brassicaceae); this is the same family as many commonly eaten vegetables, such as cauliflower.
Color photo of a green branch with long green offshoots covered in small buds. Photo: Steve Matson

Steve Matson

Section 2

Goodding's Willow

Salix gooddingii

Joshua Tree National Park has four species of willow—a surprising number for such an arid landscape! Willows are phreatophytes, plants that depend on ground water. For this reason, you will only find willows along canyon washes, near springs, or wherever there is surface water, such as at Barker Dam. All willows produce a chemical similar to aspirin called salacin; the leaves of Goodding’s willow are commonly used in Mexico for treating fevers.
Color photo of a bunch of white and pink flowers with larger faces. Photo: Steve Matson

Steve Matson


Baccharis salicifolia

Mule-fat is also common near water sources, and you might at first mistake it for a willow. In fact, salicifolia refers to the fact that the leaves resemble those of the genus Salix (willows). You can distinguish the two because mule-fat has leaves with three main veins arising from the leaf base, where willow only has one. Additionally, flowers of the two genera are completely different: mule-fat belongs to the Asteraceae family, which includes sunflowers.
Close-up photo of small flower buds surrounded by green leaves on a twig. Photo: Steve Matson

Steve Matson

Skunk Bush

Rhus aromatica

This species is our only representative of the Anacardiaceae family, which contains many species toxic to the touch, such as poison ivy and poison sumac. Don’t worry: skunk bush won’t give you a rash. It has several uses and is known to the Cahuilla people as selet and to the Chemehuevi as soo-hoo-vimp. They ate the berries raw, or dried and ground them into a powder which could be used to make a tasty drink. They also used the stalks of skunk bush in basket making; the Serrano skinned the stalks and used them as a splint base for baskets.
Color photo of tall reeds and a center brown cattail.

Broadleaf Cattail

Typha latifolia

Cattails are common and widespread at freshwater wetlands throughout North America. The broadleaf cattail, or ku’ut to the Cahuilla people, was an important traditional food source. They dried and ground the roots into a meal, and ate the more tender portions of the plant raw. The pollen from flowering stalks is high in nutrients, and the Cahuilla took advantage of this by forming it into cakes and porridges.
Color photo of a number of small white flowers in bunches.

Section 3

Heermann's Buckwheat

Eriogonum heermannii

Eriogonum is by far one of the most species-rich genera in North America. In Joshua Tree National Park alone we have 25 species! Plants in this group are important members of the desert ecosystem due to the large number of butterflies and moths that use them as a larval food source. In many cases, these butterflies are considered monophagous, meaning their caterpillars will only feed on this genus or even one particular species. The desert Sheridan’s hairstreak is an example of a butterfly that depends on Heermann’s buckwheat. This densely branched shrub can be found growing among boulders, but you won’t see the delicate white flowers until autumn.
Color photo of a small brush-like gathering of long, narrow, individual blades of pink and lilac. Photo: James Andre

James Andre

Bush Muhly

Muhlenbergia porteri

The Mojave Desert is home to many native perennial grasses, including bush muhly. You can identify this species most easily in summer, when its light pink, spreading inflorescence is in bloom. Like many grasses that thrive in the desert, bush muhly uses C4 photosynthesis. This type of photosynthesis is much more efficient at producing energy at high temperatures, because it prevents water loss through complex metabolic pathways. This strategy allows many summer-blooming species to flourish in the high heat, while other species are essentially dormant.
Bright and large yellow flower with green stamen. Photo: James Andre

James Andre

Mojave pricklypear

Opuntia phaeacantha

Pancake Cactus

Opuntia chlorotica

These two species of cactus are very closely related, but you can find distinct differences in their morphology. The pancake cactus has very round paddles, while those of the Mojave pricklypear are more oblong; the spines of the latter are generally reddish brown at the base and white at the tip, whereas the spines on pancake cactus are only one color. The biggest difference, however, is in their stature: the pancake cactus can be up to eight feet tall with a tree-like central stem at the base. The Mojave pricklypear, on the other hand, sprawls on the ground, becoming wider than tall. The pads of both species can be diced and boiled before eating. The fruit can be eaten raw, but only after removing the outer spines by rolling the fruit on the ground.
Color photo of a yellow flower with four petals. Photo: Neal Kramer

Neal Kramer


Clematis pauciflora

You will likely find this vining species supporting itself on other plants. Primarily a coastal and montane species of Southern California, clematis is at the far eastern edge of its range here in the park. It is a good example of the cismontane (mountainside) component of our park flora. This genus is known for its beautiful flowers with showy sepals and unique fruiting structures; many species are cultivated as ornamentals.
Color photo a bright purple flower with two large petals and a few smaller petals.

Fremont's Milkvetch

Astragalus lentiginosus var. fremontii

Astragalus is a diverse genus in the bean family (Fabaceae) containing many species that are extremely rare. Many are highly adapted to specific habitats or types of soil. To add to this complex diversity, this particular species has 19 recognized varieties! The best way to identify this species is to look for the rattling, inflated pods. These were ground and used as a spice for beans and other foods by the Cahuilla.
Color Species Habit Season
Arctostaphylos glauca (bigberry manzanita) shrub cool
Atriplex canescens (fourwing saltbush) shrub hot
Baccharis salicifolia (mule-fat) shrub all
Baccharis sergiloides (desert baccharis) shrub hot
Brickellia atractyloides (pungent brickellia) shrub cool
Chaenactis stevioides (Esteve's pinchusion) annual cool
Chilopsis linearis (desert willow) tree hot
Datura wrightii (jimson weed) perennial all
Eriogonum davidsonii (Davidson's buckwheat) annual all
Eriogonum fasciculatum (California buckwheat) shrub all
Eriogonum heermannii (Heermann's buckwheat) subshrub all
Eriogonum nidularium (whiskbroom buckwheat) annual all
Eriogonum saxatile (rock buckwheat) subshrub hot
Euphorbia albomarginata (rattlesnake weed) annual all
Galium angustifolium (slender bedstraw) shrub hot
Gilia stellata (star gilia), also pink to purple annual cool
Lepidium lasiocarpum (white pepperweed) annual cool
Lycium andersonii (Anderson's boxthorn) shrub cool
Lycium cooperi (Cooper's boxthorn) shrub cool
Nicotiana obtusifolia (desert tobacco) shrub cool
Nolia parryi (Parry nolina) shrub hot
Oenothera californica (California evening primrose) perennial cool
Prunus fasciculata (desert almond) shrub cool
Pseudognaphalium luteoalbum (weedy cudweed) annual
Rhamnus ilicifolia (hollyleaf redberry) perennial cool
Yucca schidigera (Mojave yucca) shrub cool
Acamptopappus sphaerocephalus (goldenhead) subshrub hot
Acmispon rigidus (desert rock pea) subshrub cold
Adenophyllum cooperi (Cooper's dyssodia) perennial cool
Ambrosia salsola (cheesebush) subshrub cool
Artemisia ludoviciana (silver wormwood) perennial hot
Bahiopsis parishii (Parish's goldeneye) shrub cool
Baileya pleniradiata (woolly marigold) annual cool
Brickellia californica (California brickellia) shrub hot
Clematis pauciflora (clematis) perennial cool
Coleogyne ramosissima (blackbrush) shrub cool
Cylindropuntia echinocarpa (silver cholla) cactus cool
Dudleya saxosa (desert live-forever) perennial cool
Ericameria cooperi (Cooper's goldenbush) shrub cool
Ericameria cuneata (rock goldenbush) shrub hot
Ericameria linearifolia (linear-leaved goldenbush) shrub cool
Gutierrezia microcephala (matchweed) subshrub hot
Larrea tridentata (creosote bush) shrub cool
Malacothrix glabrata (desert dandelion) annual cool
Opuntia chlorotica (pancake cactus) cactus cool
Opuntia phaeacantha (Mojave pricklypear) cactus hot
Quercus cornelius-mulleri (Muller oak) tree cool
Rhus aromatica (skunk bush) shrub cool
Salix gooddingii (Goodding's willow) tree
Senegalia greggii (cat's claw acacia) shrub hot
Ephedra nevadensis (Nevada jointfir) shrub cool
Sphaeralcea ambigua (apricot mallow) perennial cool
Echinocereus mojavensis (Mojave mound cactus) cactus cool
Epilobium canum (California fuschia) subshrub hot
Pink to purple
Astragalus lentiginosus var. fremontii (Fremont's milkvetch) annual, perennial all
Boechera perennans (perennial rockcress) perennial cool
Echinocereus engelmannii (hedgehog cactus) cactus cool
Eriogonum angulosum (anglestem buckwheat) annual all
Grayia spinosa (spiny hopsage) shrub cool
Nicolletia occidentalis (hole-in-the-sand plant) perennial cool
Opunita basilaris (beavertail cactus) cactus cool
Violet to blue
Amsonia tomentosa (wooly bluestar) perennial cool
Cirsium neomexicanum (New Mexico thistle) annual cool
Eriastrum eremicum (desert woollystar) annual cool
Gilia sinuata (rosy gilia) annual
Scutellaria mexicana (paper-bag bush) shrub cool
Stephanomeria exigua (small wirelettuce) annual all
Myriopteris covillei (Coville's lip fern) fern
Green to brown
Elymus elymoides (squirreltail) perennial grass hot
Hilaria rigida (big galleta grass) perennial grass all
Melica imperfecta (smallflower melicgrass) perennial grass cold
Muhlenbergia porteri (bush muhly) perennial grass hot
Phoradendron californicum (desert mistletoe) perennial cool
Poa secunda (big bluegrass) perennial grass all
Stipa speciosa (desert needlegrass) perennial grass all
Typha latifolia (broadleaf cattail) perennial hot
Juniperus californica (California juniper) shrub, tree
Pinus monophylla (single leaf pinyon pine) tree

Last updated: July 11, 2017

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