Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Phaseolus filiformis, Slimjim Bean

Slimjim Bean flowers range from pink to pink purple. They are large showy pea-like flowers and grow from leaf joints or at stem tips. The fruits are oblong, curved seed pods that open maturity (dehiscent). Phaseolus filiformis Slimjim Bean flowers are very similar to Slimleaf Bean but lack the half-moon shape which can be species diagnosis. Slimjim Bean is also called Desert Bean and Wright’s Phaseolus. Phaseolus filiformis Slimjim Bean fruits are typical legume seed pods. Here, as shown in the photo, the seep pods are curved and open at maturity. The seeds vary from 1 to many and are kidney shaped. Phaseolus filiformis Slimjim Bean has green leaves that alternate along the vine. They are pinnately compound with 3 leaflets. The leaves are deltoid, wide ovate-triangular and generally lobed. Plants have a slender taproot and cylindric or angled stems that branch at the base. Phaseolus filiformis Slimjim Bean prefers rocky soils and grows on slopes, canyons and walls. Slimjim Bean is found at elevations from 1,000 to 4,000 feet (305-1219 m). It is found in the southwestern United States in AZ, CA, NM and TX. It is also native to Baja California and northwest Mexico.  Phaseolus filiformis

Scientific Name: Phaseolus filiformis
Common Name: Slimjim Bean

Also Called: Desert Bean, Slender-stem Bean, Wright's Limabean, Wright's Phaseolus (ES: Ban Bavi)

Family: Fabaceae or Leguminosae Family

Synonyms: (Phaseolus carterae, Phaseolus sanctorum, Phaseolus wrightii)

Status: Native

Duration: Annual or short-lived perennial.

Size: Up to 12 inches, low growing vine.

Growth Form: Slimjim Bean is a forb/herb and a vine; this plant has variable growing conditions and may be observed growing upright or horizontal along the ground and it may also be climbing or trailing; the stems are covered with small hairs.

Leaves: Slimjim Bean has green leaves that are pinnately compound with 3 lobed triangular leaflets, unlike the stems, the leaves are usually without hairs.

Flower Color: Slimjim Bean has hot pink or pink-purple, pea-like flowers that are large and showy; the fruit is a curved, hairy, seed pod that breaks opens at maturity and releases its' seeds.

Flowering Season: October through November or December, or flowers throughout the year, especially after summer monsoon rainfall.

Elevation: 1,000 to 4,000 feet (305 - 1,219 m).

Habitat Preferences: Rocky soils on slopes and canyons or washes.

Recorded Range: Slimjim Bean is found in the Sonoran Desert in the southwestern United States in Arizona, California, New Mexico and Texas. It is also native to Baja California and northwest Mexico. In Arizona Slimjim Bean is found in the central and southern portions of the state.

North America & US County Distribution Map for Phaseolus filiformis.

North America species range map for Slimjim Bean, Phaseolus filiformis:

North America species range map for Slimjim Bean, Phaseolus filiformis:
Click image for full size map.

U.S. Weed Information: Unknown
Invasive/Noxious Weed Information: Unknown
Wetland Indicator: Unknown

Threatened/Endangered Information: According to the California Native Plant Society, Rare Plant Inventory, Slimjim Bean, Phaseolus filiformis is listed as a California Rare Plant Rank; 2B.1.
2B plants are "Rare or Endangered in California" but common elsewhere. The additional designation of 0.1 means that the plant is "Seriously threatened in California - Over 80% of occurrences threatened / high degree and immediacy of threat."

Genus Information: In North America, USDA Plants Database lists 12 species and 6 accepted taxa overall for Phaseolus. Worldwide, World Flora Online includes 187 accepted species names and a further 21 scientific names of infraspecific rank for the genus.

The genus Phaseolus was published in 1753 by Carl Linnaeus, (1707-1778).

In the Southwestern United States: Arizona has 7 species of Phaseolus, California and Utah each have 1 species, Nevada has 0 species, New Mexico has 6 species and Texas has 8 species. Data approximate, subject to revision.

Comments: Slimjim Bean is closely related to the Garden Beans or String Beans Phaseolus vulgaris and Butter Beans or Lima beans, Phaseolus lunatus.

In Southwest Desert Flora also see Slimleaf Bean, Phaseolus angustissimus.

Importance to Wildlife, Birds and Livestock
Slimjim Bean, Phaseolus filiformis has attractive flowers, the flowers and their seeds may be visited by hummingbirds and/or small mammals including rodents and granivorous birds in search of nectar or food.

Beneficial Value to Butterflies, Honey Bees and Insects
Slimjim Bean, Phaseolus filiformis has attractive flowers, the flowers and their plants may be visited by butterflies, moths, flies, honeybees, Native Bees and other insects in search of food and nectar.

The California Native Plant Society, has identified Slimjim Bean, Phaseolus filiformis, as a ∗likely host for the following Butterfly species;

  • Strymon melinus, Gray Hairstreak
  • Colias eurytheme, Orange Sulphur
  • Euptoieta claudia, Variegated Fritillary
  • Hemiargus ceraunus, Ceraunus Blue
  • Autographa californica, Alfalfa Looper Moth

  • ∗"Likely" host plants all belong to a known host genus for the butterflies and moths native to this location, but the individual plant species have not been verified as host plants.

    Plants shown as "likely" hosts for a given butterfly or moth must meet two requirements: 1. the genus of that plant species must be known to be eaten by the caterpillar of that butterfly or moth species, AND 2. the estimated natural geographic range of that plant species must overlap with the estimated natural geographic range of that butterfly or moth.

    Learn more at Butterflies and Moths of North America, (BAMONA).

    The genus “Phaseolus” is from the Ancient Greek word "phaselus" meaning a kind of bean with an edible pod.

    The genus Phaseolus was published in 1753 by Carl Linnaeus, (1707-1778).

    The species epithet filiformis means

    The taxon Phaseolus filiformis was described in 1844 by George Bentham, (1800-1884)

    Ethnobotany - Native American Ethnobotany; University of Michigan - Dearborn

    Date Profile Completed: 09/06/2015, updated 02/24/2022
    References and additional information:
    Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles, California, as Phaseolus wrightii.; Department of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search; accessed on-line; 02/23/2022.
    World Flora Online; A Project of the World Flora Online Consortium; An Online Flora of All Known Plants - (accessed on-line; 02/23/2022)
    Jepson 2012, Kearney and Peebles 1969; Editor: L.Crumbacher 2012; from SEINet Field Guide, on-line; accessed online 02/24/2022.
    Alfonso Delgado-Salinas 2012, Phaseolus filiformis, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on February 23, 2022.
    Dr. David Bogler, Missouri Botanical Garden; Encyclopedia of Life, - (accessed on-line 02/23/2022).
    California Native Plant Society; Calscape, Restore Nature One Garden At a Time, Slimjim Bean, Phaseolus filiformis - accessed online 02/24/2022.
    California Native Plant Society; Rare and Endangered Plant Inventory; Phaseolus filiformis, Slender-stem Bean - accessed online 02/24/2022.
    Michael J. Plagens; Arizonensis; Field Guide; Sonoran Desert Flora; Slimjim Bean, Phaseolus filiformis - (P. wrightii); accessed on-line 02/24/2022.
    Seiler, John, Peterson, John, North American species range map courtesy of Virginia Tech, Dept. of Forest Resources & Environmental Conservation
    SEINet synonyms, scientific names, geographic locations, general information.
    Etymology: Michael L. Charters California Plant Names: Latin and Greek Meanings and Derivations; A Dictionary of Botanical and Biographical Etymology - (accessed on-line; 02/23/2022)
    IPNI (2020). International Plant Names Index. Published on the Internet, The Royal Botanic Gardens, Kew, Harvard University Herbaria & Libraries and Australian National Botanic Gardens. [Retrieved on-line; 23 February 2022].