Cap Rock Trail

Color photo of a silver cholla backlight by the sun. Photo: NPS / Hannah Schwalbe
Silver cholla in the afternoon.

NPS / Hannah Schwalbe

This trail is a 0.4-mile (0.6-km) loop with minimal elevation change. It winds through Joshua tree woodland and between spectacular monzogranite rock formations, where you will find excellent examples of species capitalizing on microhabitats such as shady boulder crevices. Juniper woodlands are represented here, as well as a spectacular diversity of desert shrubs.
 
Map of the Cap Rock area. Keys View Road cuts through north-south with a small loop off to the east indicating the parking lot. Off the parking lot there is a dashed-line loop indicating the trail.

Area Map

 
Color photo of a close up of a white-petal flower with bright yellow stamen.

Section 1

Desert Almond

Prunus fasciculata
February–March

These relatives of domestic cherry and almond trees are drought-deciduous—they lose their leaves during dry periods. In spring, though, you will find them covered in leaves, and often with infestations of tent caterpillars (Malacosoma spp.). Tent caterpillars have several intriguing adaptations: for instance, they can generate heat by twitching, and they exude cyanide from their bodies to thwart would-be predators.
 
Color photo of a close up of a many-petaled yellow flower.

Woolly Marigold

Baileya pleniradiata

March–June

The woolly marigold bloom is, upon closer inspection, composed of many small flowers. This flowering head has several yellow disk florets (small flowers) in the center and a fringe of sunny yellow ray florets arranged around the edge, each with one petal. You might notice that the leaves and stem on this plant have a dense covering of tomentose (intertwined) hair, giving the plant a woolly appearance.
 
Color photo of bright purple/blue flowers with yellow stamen on a stalk.

Desert Sage

Salvia dorrii
May–June

A charismatic plant in leaf and in flower, Salvia dorrii is the eponymous plant of the classic western novel Riders of the Purple Sage and the films of the same name. If you see this woody shrub in flower, you will see why it is sometimes called purple sage—the flowers and bracts are a gorgeous dark purple. This aromatic shrub belongs to the mint family (Lamiaceae); its leaves can be used in cooking and were used to treat colds among many Native American tribes.
 
Color photo of white flowers that look like seed pods.

Steve Matson

Section 2

Indian Ricegrass

Stipa hymenoides
April–July

As the name suggests, the Chemehuevi used Indian ricegrass as a food crop. They ate the seeds raw or ground them into flour to make cakes. The inflorescence of this grass is many-branched, lending it an airy appearance. The seeds of Indian ricegrass are also a staple for many desert rodents, birds, and rabbits.
 
Color photo of long and narrow tube-like flowers on a stalk.

James Andre

California Brickellia

Brickellia californica
August–November

California brickellia is a perennial plant that blooms from late summer to early fall. The narrow flowering heads are inconspicuous, though quite pretty if you stop to look at them! There are more than three dozen species of Brickellia in the Southwest; the California brickellia is one of the most widespread. You will find this leafy shrub growing among boulders or rocky crevices, especially along wash corridors.
 
Yellow flower with many yellow stamen on a woolly stem covered in a bunch of green leaves at the base.

Rock Cinquefoil

Ivesia saxosa
April–August

The Latin translation of saxosa is “growing among rocks,” which aptly describes this plant. The rock cinquefoil is a boulder obligate—you’ll find it exclusively in volcanic or granitic crevices, such as the striking monzogranite formations that this trail is named for. Granite acts like a sponge and retains water quite well; plants with roots that can penetrate rock crevices are able to access the available moisture within.
 
Color photo of an orange-petaled flower on a green stem. Photo: James Andre

James Andre

Cooper's Dyssodia

Adenophyllum cooperi
April–June

Lean in close and experience the scent of Cooper’s dyssodia—it isn’t just visually striking! The arresting aroma of this plant is generated by oil glands near the tip of the leaves. Oil glands can also be found at the base of the phyllaries (green structures below the flowers). Plants produce oils for many purposes, such as defense against herbivory.
 
Bright pink thistle flower on spikey green head with Joshua trees in the background.

New Mexico Thistle

Cirsium neomexicanum
April–May

Though this plant only produces flowers once, it generally lives for two years. Biennials, like the New Mexico thistle, grow a large rosette (ground-level leaves) in their first year and then send up a stem and flowers in their second. The stout stem of this native thistle can grow to five feet tall and the flowering heads can be two inches wide; flower color varies from white to purple. Beware its spiny foliage!
 
Color photo of a bright yellow flower on a spiky cactus arm.

Silver Cholla

Cylindropuntia echinocarpa
April–May

The silver cholla is a stem succulent: it photosynthesizes through its stem, rather than through leaves. The leaves of cacti have been modified into spines, an adaptation that greatly reduces water loss through evaporation. This is one of the many characteristics of cacti that allow them to thrive in the desert.
 
Purple-petaled flower with a yellow head.

Steve Matson

Coville's Fleabane

Erigeron breweri
June–September

Erigeron means “early old man” in Greek, a reference to the grayish appearance of this plant caused by the coarse, stiff hairs on its stems and leaves. Your best bet at spotting this herbaceous perennial is to find it when the daisy-like flowering heads are present. These heads consist of many yellow disc florets (small flowers) surrounded by ray florets, each with one light purple petal.
 
Yellow fire-cracker shaped flowers atop stems covered in green leaves.

Rock Goldenbush

Ericameria cuneata
September–December

Give it a sniff! Like many plants that are used medicinally, rock goldenbush is aromatic due to the compounds that give it healing properties. Indigenous peoples made an infusion of its roots to cure colds and respiratory illnesses, and inhaled steam from the leaves to cure sore throats. They also made a poultice from its leaves to relieve pain and swelling.
 
Spiky base with a very large stalk completely covered in large white flowers. Some unopened, purple buds can be seen at the top of the stalks.

Mojave Yucca

Yucca schidigera
February–March

Mojave yucca is found mostly within the Mojave Desert at elevations ranging from 3000 to 5000 feet (900-1500 meters). You can distinguish it from the related Joshua tree by its long leaves and short, shrubby stature. All yuccas are pollinated by yucca moths (Tegeticula spp.) that specialize in active pollination, a rare form of pollination mutualism. The female moth lays her eggs inside the flower’s ovary, then pollinates the flower. This ensures that when the larvae emerge, they will have a fresh food source—the developing seeds!
 
Color Species Habit Season
White

Atriplex canescens (fourwing saltbush) shrub hot
Chaenactis stevioides (Esteve's pincushion) annual cool
Cryptantha circumscissa (western forget-me-not) annual cool
Cryptantha decipiens (gravelbar forget-me-not) annual cool
Datura wrightii (jimson weed) perennial all
Eriogonum fasciculatum (California buckwheat) shrub all
Euphorbia albomarginata (rattlesnake weed) annual all
Lepidium lasicocarpum (white pepperweed) annual cool
Lycium andersonii (Anderson's boxthorn) shrub cool
Lycium cooperi (Cooper's boxthorn) shrub cool
Pectacarya heterocarpa (mixed-nut comb-bur) annual cool
Prunus fasciculata (desert almond) shrub cool
Yucca brevifolia (Joshua tree) tree cool
Yucca schidigera (Mojave yucca) shrub cool
Yellow


Acamptopappus sphaerocephalus (goldenhead) subshrub cool
Adenophyllum cooperi (Cooper's dyssodia) perennial cool
Ambrosia salsola (cheesebush) subshrub cool
Amsinckia tessellata (desert fiddleneck) annual cool
Baileya pleniradiata (woolly marigold) annual cool
Brickellia californica (California brickellia) shrub hot
Camissonia campestris (Mojave suncup) annual cool
Camissoniopsis pallida (pale yellow suncup) annual cool
Coleogyne ramosissima (blackbrush) shrub cool
Cylindropuntia echinocarpa (silver cholla) cactus cool
Ericameria cooperi (Cooper's goldenbush) shrub cool
Ericameria cuneata (rock goldenbush) shrub hot
Ericameria linearifolia (linear-leaved goldenbush) shrub cool
Eriophyllum wallacei (Wallace's woolly daisy) annual cool
Gutierrezia microcephala (matchweed) subshrub hot
Ivesia saxosa (rock cinquefoil) perennial all
Leptosiphon aureus (golden linanthus) annual cool
Malacothrix glabrata (desert dandelion) annual cool
Rhus aromatica (skunk bush) shrub cool
Orange
Sphaeralcea ambigua (apricot mallow) perennial cool
Pink to purple
Amaranthus fimbriatus (fringed amaranth) annual hot
Cirsium neomexicanum (New Mexico thistle) annual cool
Krameria erecta (littleleaf ratany) shrub cool
Mirabilis laevis (wishbone bush), pink to purple and white perennial cool
Opuntia basilaris (beavertail cactus) cactus cool
Violet to blue
Erigeron breweri var. covillei (Coville's fleabane) perennial all
Salvia columbariae (chia) annual cool
Salvia dorrii (desert sage) shrub all
Scutellaria mexicana (paper-bag bush) shrub cool
Stephanomeria exigua (small wirelettuce) annual all
Green or brown
Elymus elymoides (squirreltail) perennial grass hot
Hilaria rigida (big galleta grass) perennial grass all
Melica imperfecta (smallflower melicgrass) perennial grass cool
Muhlenbergia porteri (bush muhly) perennial grass hot
Stipa hymenoides (Indian ricegrass) perennial grass cool
Stipa speciosa (desert needlegrass) perennial grass all
Cone
Ephedra nevadensis (Nevada jointfir) shrub cool
Juniperus californica (California juniper) shrub, tree

Last updated: July 11, 2017

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