Common Name: Metcalfe Bean

General Information

Phaseolus maculatus is a herbaceous perennial climbing plant growing from a fleshy, woody, globose tuber that can be 20cm or more in diameter. The twining stems can be up to 5 metres tall, scrambling over the ground and climbing into nearby vegetation for support[].
The plant is harvested from the wild for local use as a food and medicine.

Known Hazards

We have seen no specific reports for this species, but the mature seed of most, if not all, members of this genus contain various anti-nutritional factors. Soaking the seeds, discarding the water and then boiling them and discarding the water will remove these toxins and render the seeds safe and nutritious[].

Botanical References

Range

Southwestern N. America - Arizona, New Mexico, Texas to southern Mexico

Habitat

Along streams and on grassy slopes in open oak woodland, pine forests and in grassland[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial Climber
Height	4.00 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Phaseolus maculatus is native to semi-arid regions in warm temperate through the subtropical to tropical regions of southwestern N. America.
Requires a sunny position in a well-drained soil.
This species has confusing reports regarding nitrogen fixation. The subspecies maculatus has been shown not to have a symbiotic relationship. However, subspecies ritensis does have this relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

Seed - cooked[]. Toasted[]. The seedpod is 30 - 74mm long, 10 - 15mm wide, containing variously coloured, spherical seeds 7 - 13mm in diameter[].

Young seedpods - cooked[].

Thc root of subspecies ritensis is reportedly used as a fermentíng agent in making an alcoholic beverage called 'batari'[].

Medicinal

The fleshy root is used to prepare a purgative[].

Other Uses

None known

Propagation

Like many species within the family Fabaceae, once they have ripened and dried the seeds of this species may benefit from scarification before sowing in order to speed up and improve germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing[].