Skull Rock Trail

Skull-shaped rock formation surrounded by small brush, with a blue sky in the background. Photo: NPS / Robb Hannawacker
Skull Rock during the golden hour.

NPS / Robb Hannawacker

 

Trail Information

Start this dirt trail across the road from the entrance to Jumbo Rocks Campground, at the Skull Rock parking lot, or from within the campground. If you go counterclockwise rom the parking lot, the trail proceeds north of Park Boulevard through Mojave mid-elevation mixed scrub and riparian corridors, where you will see cat’s claw acacia and desert almond dominating the sandy areas. After crossing Park Boulevard you will see oak woodlands among the boulders, with California buckwheat and Mojave yucca along the ridgelines. This trail has many interpretive signs along the path and takes you by the famous Skull Rock. The last stretch of the loop follows the paved road through the campground. The loop is 1.8 miles (2.9 km) with an elevation gain of 120 feet (37 m).
 
Large pink flower with dark center.

Hedgehog Cactus

Echinocereus engelmannii
May–June

One of our more common cacti, this species forms clumps of upright, cylindrical stems. In the spring, you can identify it easily by its brilliant magenta flowers, along with the dense clusters of calico-colored spines. The hedgehog cactus relies heavily on bees for pollination. The flowers avoid self-pollinating by only opening the stigma lobes (female reproductive parts) after the bees have carried the pollen away. This is called protandry.
 
Orange-red flower with a pink and green center.

Mojave Mound Cactus

Echinocereus mojavensis
April–June

Like all members of the Cactaceae, the flowers of the Mojave mound cactus consist of many tepals, which means the petals and sepals cannot be distinguished. This is the only cactus with bright red flowers in California and it is also the only cactus pollinated by hummingbirds in this region! You will find it growing in low mounds of densely packed stems, which can reach nine feet across.
 
Tiny yellow flower with long, stringy stamens, in the joint of two reddish stems. Photo: James Andre

James Andre

Desert Trumpet

Eriogonum inflatum
all year

Despite lacking a showy flower, desert trumpet stands out at any time of the year because of its inflated stems. The fistulose (hollow) portion of the stem occurs just below the whorl of branches. The amount of inflation is dependent on available moisture and is caused by carbon dioxide concentration. During drier periods of the year, the inflation will be less pronounced or lacking altogether. You can find these tall, airy plants throughout the park in a variety of habitats; watch for them along the roadside.
 
Yellow flower with three lower petals and two upper petals that have curved over the stamens.

Bush Penstemon

Keckiella antirrhinoides
April–June

The bush penstemon, also called a beardtongue, is aptly named. It is in the same family as domestic snapdragons, and like those flowers it has a furry pistil that looks like a “bearded tongue” for gathering pollen from visiting insects. Note the downward-facing, fused petals. These provide a landing platform for pollinators, and the overhanging petals and anthers deposit pollen on the insect while it gathers nectar. This woody shrub is quite showy with its large yellow flowers and shiny green leaves. Look for it on rocky slopes.
 
Pink-hued flower with darker pink stripes down the center of each petal, with a yellow head.

Cushion Foxtail Cactus

Coryphantha alversonii
April–June

Cushion foxtail cactus, a stem succulent, is known for its brilliant pink bloom and reddish black tipped spines. It can be locally common throughout Joshua Tree National Park, but has a limited distribution. It is restricted to a small region in the transition zone between the Mojave and Sonoran Deserts in California, making it endemic to the state and of conservation concern.
 
Small white flowers on a long straw-colored stem.

Wright's Buckwheat

Eriogonum wrightii
August–February

The sweet nectar of Wright’s buckwheat provides nourishment for a great diversity of native bee pollinators, as well as butterflies such as the beautiful Mormon metalmark. This common but unassuming shrub reminds us that by protecting our native vegetation we also protect a multitude of other species.
 
Close-up photo of a green fern.

Viscid Lip Fern

Myriopteris viscida

The name, viscid lip fern, refers to the clear sticky substance exuded from the dense covering of glands on the leaf surfaces. Many members of the genus Myriopteris produce chemicals that help to block certain types of UV radiation, effectively protecting themselves from sun damage in harsh, xeric landscapes. You will find this plant in protected, rocky areas.
 
Tiny lilac purple flowers with minute yellow centers on green stems.

Bigfoot Hybrid Rockcress

Boechera xylopoda
March–May

You will typically find the bigfoot hybrid rockcress growing on gravelly slopes, rocky outcrops, or in the shade of a tree. The erect flowering stalk emerges from a small rosette of dark green leaves and the flowers have four purple petals. The skinny fruits, called siliques, are quite noticeable on these plants and are often covered with small stellate (star-shaped) hairs.
 
Yellow-orange flower with complex stamen center. Photo: Steve Matson

Steve Matson

Broom Matchweed

Gutierrezia saronthrae
May–October

Broom matchweed is highly aromatic and flammable due to the resins in the leaves – hence the common name matchweed. The aromatic compounds lend it healing properties: for example, the Cahuilla used the plant as a cure for toothaches and other pains. The name sarothrae means “broom” in Greek, referring to the densely branched herbaceous stems that work well as a broom.
 
Small white flower with star-shaped yellow center. Photo: James Andre

James Andre

Woody Forget-me-not

Cryptantha racemosa
February–May

Although many members of this genus are annuals, the woody base of this species helps to distinguish it as a perennial. You can find woody forget-me-not growing from rock crevices, often along canyon walls. The small, white flowers and bristly hairs make the members of this genus difficult to tell apart, but if you can get a closer look at the nutlets (seeds) you will see a myriad of differences. The species name comes from the Latin meaning for “clustered,” referring to the shape of the flowering stalk.
 
Color photo of a large, light pink flower.

Beavertail Cactus

Opuntia basilaris
March–June

This cactus has flat, blue-gray pads that are spineless and appear fuzzy and soft, tempting people to make the mistake of touching them. Beware: instead of spines, they are armed with many small bristles known as glochids, which are painful and very difficult to remove! The species name basilaris means “regal,” referring to the plant’s beauty when covered with large, nearly neon pink flowers. Ants can often be found swarming the newly formed pads and flowers due to the copious amounts of nectar they produce. Native Americans traditionally used beavertail cactus for both food and medicine.
 
Narrow and long red flower on a dark green stem.

California Fuschia

Epilobium canum
June–December

An herbaceous perennial, California fuschia grows in the bottoms of canyons, along washes, or wherever there is moisture seeping from a crevice. Look for it during the summer and fall months, when it is covered in tube-shaped red to orange flowers. These flowers exhibit the classic morphology of a plant pollinated by birds: the red color is highly visible; the tubular shape holds nectar at the base, requiring the bird to get pollen on its face as it delves deep for food; and there is little scent.
 
Color Species Habit Season
White
Ambrosia dumosa (burrobush) shrub cool
Brickellia atractyloides (pungent brickellia) shrub cool
Chaenactis fremontiiI (Fremont pincushion) annual cool
Chaenactis stevioides (Esteve's pincushion) annual cool
Cryptantha angustifolia (narrow-leaf forget-me-not) annual cool
Cryptantha barbigera (bearded forget-me-not) annual cool
Cryptantha circumscissa (western forget-me-not) annual cool
Cryptantha decipens (gravelbar forget-me-not) annual cool
Cryptantha dumetorum (bush-loving forget-me-not) annual cool
Cryptantha maritima (white-haired forget-me-not) annual cool
Cryptantha micrantha (red-root forget-me-not) annual all
Cryptantha nevadensis (Nevada forget-me-not) annual cool
Cryptantha pterocarya (wingnut forget-me-not) annual cool
Cryptantha utahensis (scented forget-me-not) annual cool
Descurainia pinnata (tansy mustard) annual cool
Eriogonum fasciculatum (California buckwheat) shrub all
Eriogonum saxatile (rock buckwheat) subshrub hot
Eucrypta chrysanthemifolia (spotted eucrypta) annual cool
Euphorbia albomarginata (rattlesnake weed) annual all
Galium angustifolium (slender bedstraw) shrub hot
Galium stellatum (starry bedstraw) subshrub cool
Lepidium lasiocarpum (white pepperweed) annual cool
Lycium andersonii (Anderson's boxthorn) shrub cool
Porophyllum gracile (odora) subshrub cool
Prunus fasciculata (desert almond) shrub cool
Rafinesquia neomexicana (New Mexico chicory) annual cool
Thysanocarpus curvipes (fringe-pod) annual cool
Yucca brevifolia (Joshua tree) tree cool
Yucca schidigera (Mojave yucca) shrub cool
Yellow
Acmispon rigidus (desert rock pea) subshrub cool
Amsinckia tessellata (desert fiddleneck) annual cool
Anisocoma acaulis (scalebud) annual cool
Artemisia ludoviciana (silver wormwood) perennial hot
Bahiopsis parishii (Parish's goldeneye) shrub cool
Brickellia californica (California brickellia) shrub hot
Cylindropuntia echinocarpa (silver cholla) cactus cool
Cylindropuntia ramosissima (pencil cholla) cactus hot
Dudleya saxosa (desert live-forever) perennial cool
Encelia actonii (Acton's brittlebush) shrub all
Ericameria cuneata (rock goldenbush) shrub hot
Ericameria linearifolia (linear-leaved goldenbush) shrub cool
Ericameria teretifolia (terete-leaved rabbitbrush) shrub hot
Eriogonum pusillum (yellow turbans) annual all
Eriophyllum wallacei (Wallace's woolly daisy) annual cool
Eschscholzia minutiflora (little gold poppy) annual cool
Keckiella antirrhinoides (bush penstemon) shrub cool
Larrea tridentata (creosote bush) shrub cool
Opuntia chlorotica (pancake cactus) cactus cool
Quercus cornelius-mulleri (Muller oak) tree cool
Rhus aromatica (skunk bush) shrub cool
Senegalia greggii (cat's claw acacia) shrub hot
Senna armata (desert senna) shrub all
Tetradymia stenolepis (Mojave cottonthorn) shrub hot
Orange
Adenophyllum porophylloides (San Felipe dyssodia) subshrub cool
Sphaeralcea ambigua (apricot mallow) perennial cool
Red
Calyptridium monandrum (sand-cress) annual all
Castilleja chromosa (desert paintbrush) perennial hot
Echinocereus mojavensis (Mojave mound cactus) cactus cool
Epilobium canum (California fuschia) subshrub hot
Lomatium mohavense (Mojave desert parsley) perennial cool
Pink to purple
Boechera xylopoda (bigfoot hybrid rockcress) perennial cool
Coryphantha alversonii (cushion foxtail cactus) perennial cool
Echinocereus engelmannii (hedgehog cactus) cactus cool
Eriogonum wrightii (Wright's buckwheat) subshrub hot
Krameria erecta (littleleaf ratany) shrub cool
Mirabilis laevis (wishbone bush), pink to purple, and white perennial cool
Opuntia basilaris (beavertail cactus) cactus cool
Stephanomeria pauciflora (brownplume wirelettuce) subshrub cool
Violet to blue
Delphinium parishii (Parish's larkspur) perennial cool
Eristrum eremicum (desert woollystar) annual cool
Lupinus concinnus (elegent lupine) annual cool
Lupinus sparsiflorus (Arizona lupine) annual cool
Phacelia distans (lace-leaf phacelia) annual cool
Salvia columbariae (chia) annual cool
Scutellaria mexicana (paper-bag bush) shrub cool
Thamnosma montana (turpentine broom) shrub cool
Xylorhiza tortifolia (Mojave aster) shrub cool
Fern
Myriopteris viscida (viscid lip fern) perennial
Green
Aristida purpurea (Fendler's threeawn) perennial grass hot
Phoradendron californicum (desert mistletoe) perennial cool
Simmondsia chinensis (jojoba) shrub cool
Stipa speciosa (desert needlegrass) perennial grass all
Cone
Ephedra nevadensis (Nevada jointfir) shrub cool
Juniperus californica (California juniper) shrub, tree
Pinus monophylla (singleleaf pinyon pine) tree

Last updated: July 14, 2017

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Twentynine Palms, CA 92277-3597

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