Taxonomic notes: Phaseolus albescens McVaugh ex R. Delgad. & A. Delgado is a secondary wild relative of common bean, P. vulgaris L. var. vulgaris, and scarlet runner bean, P. coccineus L. (USDA, ARS, National Genetic Resources Program 2015).

Phaseolus albescens is endemic to southern Mexico where it occurs in the regions of Colima, Guerrero, Jalisco and Michoacan (USDA, ARS, National Genetic Resources Program 2015). Based on occurrence data provided by Crop Wild Relatives and Climate Change (2013), its extent of occurrence (EOO) is less than 20,000 km².

This vine of up to 10 m in length climbs on trees in wet ravines and on steep slopes between volcanic and calcareous rocks in cloud forests of firs and broad-leaved trees (Freytag and Debouck 2002). Specimens have been collected from elevations of 1,600–1,900 and 2,000–2,350 m (Freytag and Debouck 2002).

Freytag and Debouck (2002 p. 50) described this species as "locally abundant" but restricted to montane cloud forests of western Mexico.

It is a secondary wild relative of, and potential gene donor to common and scarlet runner bean (USDA, ARS, National Genetic Resources Program 2015).

Freytag and Debouck (2002 p. 50) noted that the restricted habitat of P. albescens is threatened by "excessive logging and habitat alteration".

• 5.3.2 Intentional use: (large scale) [harvest]
• 7.3 Other ecosystem modifications

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Phaseolus albescens has an extent of occurrence (EOO) of less than 20,000 km² and there is a continuing decline in the area, extent and quality of its habitat due to excessive logging EXPERTS: CAN WE SAY THAT THERE IS A CONTINUING DECLINE? The population is severely fragmented as the taxon is restricted to montane cloud forests of western Mexico and recorded subpopulations at nine localities are separated by distances of 5 km or more. Based on the observed decline in the quality of its habitat, there is also a suspected population reduction of at least 30% within a ten year period in the past. EXPERTS: CAN WE ASSUME THIS? The species is therefore assessed as Vulnerable.

• Crop Wild Relatives and Climate Change. 2013. Crop Wild Relative Global Occurrence Database. Available at: http://www.cwrdiversity.org/checklist/cwr-occurrences.php.
• Freytag, G.F. and Debouck, D.G. 2002. Taxonomy, Distribution, and Ecology of the Genus Phaseolus (Leguminosae–Papilionoideae) in North America, Mexico and Central America. Botanical Research Institute of Texas, Fort Worth.
• USDA, ARS, National Genetic Resources Program. 2015. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. Available at: http://www.ars-grin.gov/.