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Rhynchosia spp.
Snoutbeans
Pantropical and warm temperate regions worldwide
Overview
Rhynchosia is a large genus of roughly 200 species of perennial herbs, twining vines, and low subshrubs in the pea family, Fabaceae. It is pantropical and extends into warm temperate regions, with species across the Americas, Africa, Asia, and Australia. Most plants have the three-parted (trifoliate) leaves typical of the bean family, often dotted with tiny resin glands, and they twine, trail, or stand as small bushy subshrubs depending on the species. The pea-like flowers are usually yellow, sometimes marked with thin reddish or purple lines, and are borne singly or in short racemes from the leaf axils. Short, flattened pods follow, each commonly holding two seeds; in several species these seeds are bicolored bright red and black and have been used as beads. As legumes, Rhynchosia species fix nitrogen through root-nodule bacteria and often grow on poor soils. Most are plants of grassland, scrub, open woodland, and disturbed ground in warm climates, and many are frost-tender. Some twining species can scramble widely and need support or room, and a few are weedy where conditions suit them. The bicolored seeds of some species are reported to be toxic if eaten.
Native Range
Rhynchosia has a pantropical distribution, native across the warmer parts of the Americas, sub-Saharan Africa, southern and eastern Asia, and Australia, reaching into warm temperate zones such as the southern United States. Species grow in grassland, thickets, open woodland, coastal scrub, and disturbed roadsides.Suggested Uses
Rhynchosia is grown in native, wildlife, and naturalistic plantings, on banks and slopes for cover, and as a nitrogen-fixing component of warm-climate grassland mixes. Twining species are trained over fences and trellises, and the flowers draw bees and other pollinators. Some species are grown mainly for their red-and-black ornamental seeds.How to Identify
Appearance
Size & Dimensions
Height1' - 10'
Width/Spread1' - 6'
Bloom Information
Most Rhynchosia species flower through the warm season, generally summer into autumn, with timing tied to rainfall in seasonally dry climates. The small yellow flowers open over many weeks as the stems lengthen. Pods ripen and dry in the weeks after flowering.
Detailed Descriptions
Flower Description
yellow, sometimes with reddish linesFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 5-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight