The Desert Five-Spot (Eremalche rotundifolia) is a striking annual wildflower commonly observed in Death Valley National Park, particularly during favorable bloom years following sufficient winter rainfall.
Scientific Taxonomy
- Kingdom: Plantae
- Phylum: Tracheophyta (vascular plants)
- Class: Magnoliopsida (dicotyledons)
- Order: Malvales
- Family: Malvaceae (mallow family, which includes hibiscus and cotton)
- Genus: Eremalche
- Species: Eremalche rotundifolia (A. Gray) Greene
This species is a dicotyledonous annual herb native to desert regions.
Description
The desert five-spot is a low-growing annual herb typically reaching 8–60 cm (3–24 inches) in height. It has an erect, sparsely branched stem (often simple or branched only at the base) covered in bristly hairs; stems are frequently reddish-brown. The leaves are distinctive: rounded to kidney-shaped (reniform), 1.5–6 cm broad, with toothed or crenate margins, and borne on long petioles. Leaves are green (sometimes with reddish phases) and covered in short bristly hairs.
The most striking feature is the flower: bisexual, cup- to globe-shaped, with five overlapping petals 15–30 mm long. Petals are rose-pink to lilac or purplish-pink, each featuring a prominent dark red-to-purple spot at the base that serves as a nectar guide for pollinators. When fully open, the petals curve slightly inward, forming a nearly spherical “lantern” shape (hence the occasional nickname “Chinese lantern flower”). The center reveals a ring of light pink stigmas surrounding smaller stamens. The calyx has 5 lobes, and three small bractlets subtend it. After flowering, the plant produces a schizocarp fruit that splits into 25–35 wafer-like segments.
Note on identification: Do not confuse it with the unrelated “five-spot” (Nemophila maculata), a white-flowered plant of the Sierra Nevada and foothills with purple spots at the petal tips.
Blooming Period and Behavior
Flowering occurs primarily from March to May, with peak displays in the lower desert elevations from mid-February through mid-April, depending on winter rainfall. In Death Valley National Park, it is a signature wildflower during “superbloom” years (such as the notable events following heavy rains).
The flowers exhibit daily nyctinastic movement: they open in the morning (or midday) to reveal the vivid red spots and close at night or late afternoon. Leaves also show diurnal movement to optimize sunlight exposure. The red basal spots on each petal function as “runways” directing bees and other insects to the nectar at the flower base, aiding pollination. The plant thrives in years with adequate winter precipitation and is one of the more sought-after desert wildflowers for its vivid color contrast against the arid landscape.
Range and Distribution
Eremalche rotundifolia is native to the Mojave Desert and Colorado Desert (part of the Sonoran Desert region) in the southwestern United States and northwestern Mexico. It occurs in southeastern California (including Death Valley National Park and Anza-Borrego Desert State Park), southern Nevada, western Arizona, and extends slightly into Utah. In California it is found primarily in the Desert bioregion (excluding the high Desert Mountains). Elevation range is approximately -50 to 1,500 m (-164 to 4,921 ft), though it is most common between 50 and 1,200 m.
Habitat and Ecology
This species prefers open, sunny sites in dry desert scrub, desert flats, sandy or rocky washes, alluvial fans, and open stony areas. It grows best in fast-draining, gravelly alkaline soils and is frequently associated with creosote bush scrub communities. In Death Valley National Park it appears on lower-elevation alluvial fans, foothills, and along roadsides (e.g., Badwater Road areas) following sufficient winter rains.
As an annual, it completes its life cycle quickly after winter rains, producing abundant seeds that remain dormant in the soil until the next favorable season. It provides nectar for native bees and supports larvae of certain butterflies and skippers (including confirmed hosts for Northern White-Skipper and Common Checkered-Skipper).
The desert five-spot is a beautiful and iconic Mojave Desert wildflower, particularly celebrated in Death Valley for its glowing pink blooms and striking red-spotted “lantern” flowers during spring displays. Its presence is highly dependent on winter precipitation, making it a highlight of rare superbloom events.