Supine Bean / Center For Plant Conservation
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Plant Profile

Supine Bean (Macroptilium supinum)

The beautiful salmon-colored flower of Macroptilium supinum. Photo Credit: Lynda Pritchett-Kozak
  • Global Rank: G2 - Imperiled
  • Legal Status: N/A
  • Family: Fabaceae
  • State: AZ, SI
  • Nature Serve ID: 154214
  • Lifeform: Forb/herb, Vine
  • Date Inducted in National Collection: 03/14/1986
Description:

Macroptilium supinum, a perennial herb, is found in grass woodlands in Arizona and Mexico (Toolin 1982). This species has an unusual breeding syndrome. Flower and seed production occur both above and below ground. Below ground flowers remain closed and are obligate selfers (Buhrow 1983), not requiring pollinator services . Oddly, most seeds are produced in this manner, potentially acting as an inherent preplanting mechanism.

Where is Supine Bean (Macroptilium supinum) located in the wild?

Habitat:

Plants prefer grassland and oak woodland habitats, which are threatened by overgrazing, off-road activity, development and reservoir construction (Pena Blanca Lake) (USFWS 1980).

Distribution:

The type locality for Macroptilium supinum is located 19 miles N of La Colorada, Mexico. The entire range of M. supinum ranges from Sonora and Nayarit north into Santa Cruz County, Arizona (Toolin 19

States & Provinces:

Supine Bean can be found in Arizona, Sonora

Which CPC Partners conserve Supine Bean (Macroptilium supinum)?

  • Desert Botanical Garden

    Not Sponsored
    Conservation Actions
    Assigned 06/09/17
    • CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

    Conservation Actions

    • 10/06/2020
      • Living Collection

    Desert Botanical Garden has only 116 seeds of Macroptilium supinum from two populations. Twelve plants were produced from a germination test using 25 seeds. The initial germination percentage was 88%, but some seedlings were lost due to damping off. Plants were placed in a greenhouse and were gradually nibbled away by an unknown animal, even in the greenhouse. A related species, M. atropurpureum, was grown from seed and plants were transplanted into the ground. Within 24 hours, the plants and caudexes were gone, presumably eaten by ground squirrels. (Desert Botanical Gardens 2000)

    • 10/06/2020
      • Propagation Research

    Desert Botanical Garden has only 116 seeds of Macroptilium supinum from two populations. Twelve plants were produced from a germination test using 25 seeds. The initial germination percentage was 88%, but some seedlings were lost due to damping off. Plants were placed in a greenhouse and were gradually nibbled away by an unknown animal, even in the greenhouse. A related species, M. atropurpureum, was grown from seed and plants were transplanted into the ground. Within 24 hours, the plants and caudexes were gone, presumably eaten by ground squirrels. (Desert Botanical Gardens 2000)

    • 10/06/2020
      • Orthodox Seed Banking

    Desert Botanical Garden has only 116 seeds of Macroptilium supinum from two populations. Twelve plants were produced from a germination test using 25 seeds. The initial germination percentage was 88%, but some seedlings were lost due to damping off. Plants were placed in a greenhouse and were gradually nibbled away by an unknown animal, even in the greenhouse. A related species, M. atropurpureum, was grown from seed and plants were transplanted into the ground. Within 24 hours, the plants and caudexes were gone, presumably eaten by ground squirrels. (Desert Botanical Gardens 2000)

    • 10/06/2020
      • Seed Collection

    Desert Botanical Garden has only 116 seeds of Macroptilium supinum from two populations. Twelve plants were produced from a germination test using 25 seeds. The initial germination percentage was 88%, but some seedlings were lost due to damping off. Plants were placed in a greenhouse and were gradually nibbled away by an unknown animal, even in the greenhouse. A related species, M. atropurpureum, was grown from seed and plants were transplanted into the ground. Within 24 hours, the plants and caudexes were gone, presumably eaten by ground squirrels. (Desert Botanical Gardens 2000)

    Nature Serve Biotics
    • 05/02/2017

    Known only from a few localities in Arizona, and Sonora and Nayarit, Mexico. No plants were found at the type locality in Sonora during a 1990 survey, but in the same year several other populations were discovered in the northern part of the state. These are believed to be stable, secure populations, as no habitat disturbances are evident in the region.

    Kathleen C. Rice
    • 01/01/2010

    Predation by rodents and grazing by cattle are the primary threats to this highly palatable species (USFWS 1980, Toolin 1980, 1982). Habitat degradation caused by grazing is a secondary threat (Toolin 1982).

    Kathleen C. Rice
    • 01/01/2010

    The total known U.S. population consists of approximately 1000 plants (Toolin 1982, Gori et al. 1990).

    Kathleen C. Rice
    • 01/01/2010

    Desert Botanical Garden has only 116 seeds of Macroptilium supinum from two populations. Twelve plants were produced from a germination test using 25 seeds. The initial germination percentage was 88%, but some seedlings were lost due to damping off. Plants were placed in a greenhouse and were gradually nibbled away by an unknown animal, even in the greenhouse. A related species, M. atropurpureum, was grown from seed and plants were transplanted into the ground. Within 24 hours, the plants and caudexes were gone, presumably eaten by ground squirrels. (Desert Botanical Gardens 2000)

    Kathleen C. Rice
    • 01/01/2010

    Populations are monitored.

    Kathleen C. Rice
    • 01/01/2010

    A management plan controlling grazing would be useful. Fire ecology may be a useful management tool, but research is needed. Research needs include understanding seedling establishment and recruitment.

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    Nomenclature
    Taxon Macroptilium supinum
    Authority (Wiggins & Rollins) A. Delgado & L. Torres
    Family Fabaceae
    CPC Number 3382
    ITIS 819760
    USDA MASU18
    Duration Perennial
    Common Names supine bean
    Associated Scientific Names Macroptilium supinum | Phaseolus supinus
    Distribution The type locality for Macroptilium supinum is located 19 miles N of La Colorada, Mexico. The entire range of M. supinum ranges from Sonora and Nayarit north into Santa Cruz County, Arizona (Toolin 19
    State Rank
    State State Rank
    Arizona S1
    Sonora S1
    Ecological Relationships

    Photos

    The beautiful salmon-colored flower of Macroptilium supinum. Photo Credit: Lynda Pritchett-Kozak

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