Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

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

Cirsium ochrocentrum, Yellowspine Thistle

Phaseolus angustissimus, Slimleaf Bean

Slimleaf Bean flowers are purple, pink or lavender. The flowers are typical “pea” type flowers and the “keel” petal is noticeably twisted or curved as shown in the photo. Phaseolus angustissimus Slimleaf Bean flowers blooms from May to October. Fruits are formed shortly thereafter. The fruits are narrow flat seed pods, curved or half-moon shaped up to 3 inches (76 mm) long. Phaseolus angustissimusSlimleaf Bean is a native perennial that grows up to 10 inches (25.4 cm) high is very similar in appearance to Slimjim Bean. Phaseolus angustissimusSlimleaf Bean has pinnately compound dark green leaves. The leaves alternate along a twining vine and vary in shape but generally linear-lanceolate leaflets or oblong-lanceolate leaflets.  Phaseolus angustissimusSlimleaf Bean preferred habitats include mesas often growing within trees and shrubs; elevations from 3,500 to 7,500 feet (1,066 to 2,285 m). They are found in the southwestern United States in AZ, NM and TX.  Phaseolus angustissimus

Scientific Name: Phaseolus angustissimus
Common Name: Slimleaf Bean

Also Called: Narrowleaf Bean, Narrow-Leaflet Bean

Family: Fabaceae or Leguminosae Family

Synonyms: (Phaseolus angustissimus var. latus)

Status: Native

Duration: Perennial

Size: Up to 10 inches (25.4 cm) high.

Growth Form: Forb/herb and/or a vine; thick taproot, plants glabrous; stems branched, slender, trailing, twining.

Leaves: Green, dark green; alternate; pinnately compound; trifoliolate or trifoliate leaf shape variable with variety, generally linear-lanceolate leaflets or oblong-lanceolate leaflets often sub-hastately lobed (slightly arrowhead shaped) at base.

Flower Color: Purple, pink or lavender; inflorescence a raceme from leaf axils, multiple flowers (2 to 5), typical pea type flower noticeably twisted or curved inward on the keel petal, often yellowish; fruits a narrow flat seed pod, (slightly pubescent to glabrous) curved or half-moon shaped, up to 3 inches (76 mm) long.

Flowering Season: May to October

Elevation: 3,500 to 7,500 feet (1,066 to 2,285 m)

Habitat Preferences: Mesas often growing within trees and shrubs.

Recorded Range: Slimleaf Bean is found in the southwestern United States in AZ, NM and TX. It is also native to northern Mexico.

North America & US County Distribution Map for Phaseolus angustissimus.

U.S. Weed Information: No information available.
Invasive/Noxious Weed Information: No information available.
Wetland Indicator: No information available.
Threatened/Endangered Information: No information available.

Genus Information: 12 species in Phaseolus in the United States. Recent taxonomic changes have moved several species from the genus Phaseolus to Macroptilium, Vigna and Strophostyles. Worldwide, The Plant List includes 97 accepted species names and a further 45 scientific names of infraspecific rank for the genus.

The genus Phaseolus is one of the most important genera in the Fabaceae family as they are used for cooking in either fresh or dried form. Several species have been cultivated for their beans which are rich in protein and contain iron, thiamin and riboflavin. The genus Phaseolus is native to the Americas.

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

Comments: The Arizona type species for Phaseolus angustissimus (recognized as variety latus), was collected along the Little Colorado River near Winslow, Navajo County (Jones in 1980). Unlike similar plants of the same genus, Slimleaf Bean may be differentiated by the fact that it is a perennial plant from woody rootstock.

Slimleaf Bean is a close relative of the cultivated tepary bean (P. acutifolius) which is also native.

In Southwest Desert Flora also see Slimjim Bean, Phaseolus filiformis.

Etymology:
The genus Phaseolus is from the Ancient Greek word "phaselus" meaning a kind of bean with an edible pod. The species epithet angustissimus means narrow or narrowed a reference to its narrow foliage.

Ethnobotany
Slimleaf Bean has been used as a pediatric aid and drug strengthener by the Zuni tribe.
  • Zuni Drug, Pediatric Aid, Crushed leaves, blossoms and powdered root rubbed on a child's body as a strengthener. When an infant boy showed signs of timidity, his father carried a small quantity of corn meal wrapped in a bit of corn husk to the warrior of his choice, presented it and asked that the warrior apply the medicine on his child's body so that he may have a brave heart and never be afraid of the enemy. The warrior then chewed the crushed leaves and blossoms and the powdered root, ejected the mass into his hands and rubbed it all over the child's body.
  • Zuni Drug, Strengthener, Crushed leaves, blossoms and powdered root rubbed on a child's body as a strengthener. When an infant boy showed signs of timidity, his father carried a small quantity of corn meal wrapped in a bit of corn husk to the warrior of his choice, presented it and asked that the warrior apply the medicine on his child's body so that he may have a brave heart and never be afraid of the enemy. The warrior then chewed the crushed leaves and blossoms and the powdered root, ejected the mass into his hands and rubbed it all over the child's body.

  • See complete listing of ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.

    Date Profile Completed: 11/15/2019
    References:
    Kearney, Thomas H., Peebles, Robert H., 1960, Arizona Flora, University of California Press, Berkley and Los Angeles, California.
    Kearney and Peebles 1969, McDougall 1973, Allred and Ivey 2012, Heil et al. 2013, from SEINet - (accessed 11/08/2019)
    U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - (accessed 11/14/2019)
    https://plants.usda.gov/java/ClassificationServlet?source=profile&symbol=PHASE&display=31
    The Plant List (2013). Version 1.1. Published on the Internet; http://www.theplantlist.org/ (accessed 11/14/2019).
    http://www.theplantlist.org/1.1/browse/A/Leguminosae/Phaseolus/
    Wikipedia contributors, 'Phaseolus', Wikipedia, The Free Encyclopedia, 14 September 2019, 11:03 UTC,
    https://en.wikipedia.org/w/index.php?title=Phaseolus&oldid=915627956 [accessed 8 November 2019]
    "Phaseolus, Bean Plant". Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica Inc., LAST UPDATED: Sep 26, 2019 - (accessed 10/09/2019).
    https://www.britannica.com/plant/bean#ref1183845
    SEINet synonyms, scientific names, geographic locations, general information, (accessed 11/14/2019).
    http://swbiodiversity.org/seinet/
    ETYMOLOGY: Michael L. Charters; California Plant Names: Latin and Greek Meanings and Derivations; A Dictionary of Botanical and Biographical Etymology; (accessed 11/08/2019)
    http://www.calflora.net/botanicalnames/pageAN-AZ.html
    Wiktionary contributors, 'phaselus', Wiktionary, The Free Dictionary, 4 August 2019, 10:38 UTC,
    https://en.wiktionary.org/w/index.php?title=phaselus&oldid=53812667 [accessed 8 November 2019]