CPC Plant Profile: Supine Bean
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Plant Profile

Supine Bean (Macroptilium supinum)

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

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.

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Updates
  • 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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Photos
Nomenclature
Taxon Macroptilium supinum
Authority (Wiggins & Rollins) A. Delgado & L. Torres
Family Fabaceae
CPC Number 3382
ITIS 819760
USDA MASU18
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
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).

Ecological Relationships

Unknown.

Pollinators
Common Name Name in Text Association Type Source InteractionID
Reintroduction
Lead Institution State Reintroduction Type Year of First Outplanting

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