Burny bean

Names and Synonyms

Common Names

• black-bean
• velvet-bean
• Burny Bean
• seabean

Scientific Names

Accepted name

Synonyms

• Carpopogon giganteus
• Dolichos giganteus
• Stizolobium giganteum
• Negretia gigantea

Regional and Traditional Names

Sources: Wikidata, Catalogue of Life

Taxonomical Classification

This plant belongs to the kingdom Plantae and the phylum Streptophyta, falling under the class Equisetopsida and subclass Magnoliidae. Within the order Fabales, it is classified under the family Fabaceae. Finally, it is specifically identified by the genus Mucuna.

Sources: The World Checklist of Vascular Plants (WCVP)

Distribution

This plant exhibits a broad distribution across several key regions of the African continent. In West-Central Tropical Africa, it can be found growing within the Democratic Republic of the Congo. Its presence extends into East Tropical Africa, where it inhabits Kenya, Tanzania, and Uganda. Furthermore, the species is documented in the South Tropical Africa region, specifically in Mozambique. Together, these locations highlight the wide ecological range of this medicinal species.

Sources: The World Checklist of Vascular Plants (WCVP)

Botanical Identification

Ecology

The ecology of Mucuna gigantea is characterized by its preference for humid, tropical environments, specifically thriving within the lush conditions of rain forests, dense secondary shrublands, and ruderal vegetation. This species demonstrates a remarkable capacity to colonize disturbed areas and rapidly growing secondary growth, where it can exploit available light and nutrients. Regarding its altitudinal distribution, the plant is primarily found at extremely low elevations, with its maximum recorded elevational range reaching only 2 m AMSL, indicating a specialized niche within lowland, coastal, or riverine ecosystems.

Elevational range max:

2 m AMSL

Habitat :

rain forest, dense secondary shrub and ruderal vegetation

Life history

The life history of Mucuna gigantea is characterized by its classification as a perennial plant, meaning it possesses the capacity to live through multiple growing seasons rather than completing its cycle in a single year. As a robust, climbing legume, its developmental trajectory involves establishing a vigorous root system that supports extensive woody vines capable of scaling significant heights in search of sunlight. Throughout its lifecycle, the plant undergoes distinct vegetative and reproductive phases, transitioning from rapid stem elongation and foliage production to the emergence of large, showy flowers. These reproductive stages are essential for the production of its characteristic large, dark pods, which eventually release seeds to ensure the continuation of the species. Depending on environmental stability and resource availability, its growth pattern can exhibit variability, yet it fundamentally functions as a long-lived organism within its ecological niche.

Lifecycle :

perennial

Morphology

The morphology of Mucuna gigantea is characterized by its robust, woody growth habit, functioning as an obligatory liana. This climbing plant is strictly terrestrial and independent, meaning it does not act as a parasite or an epiphyte. As a large-scale climber, it exhibits significant verticality, with a plant height that typically averages around 10 m, though it can range from a minimum of 5 m to a maximum height of 30 m. While its growth form is categorized under broader classifications as both a herb and other specialized structures, its primary physical manifestation is that of a massive, woody vine.

Aquatic :

terrestrial

Climber :

liana

Climber :

obligatory

Epiphyte :

terrestrial

Growth form :

herb

Growth form :

other

Parasite :

independent

Plant height max:

30 m

Plant height mean:

10 m

Plant height min:

5 m

Woodiness :

woody

Physiology

The physiology of Mucuna gigantea is characterized by several specialized metabolic and morphological adaptations. As a nitrogen fixer, the plant engages in a symbiotic relationship with bacteria to convert atmospheric nitrogen into usable forms, enhancing soil fertility and supporting its rapid growth. It utilizes the C3 photosynthetic pathway, a common carbon fixation process that allows the plant to synthesize organic compounds under standard environmental conditions. Morphologically, the plant exhibits non-succulent foliage, meaning its leaves lack significant water-storage tissue. The leaves vary in size, with lengths ranging from a minimum of 4 cm to a maximum of 16 cm, and widths spanning from a minimum of 2 cm to a maximum of 9 cm.

Leaf length max:

16 cm

Leaf length min:

4 cm

Leaf width max:

9 cm

Leaf width min:

2 cm

Nitrogen fixer :

yes

Photosynthetic pathway :

C3

Succulence :

no

Reproduction

The reproduction of Mucuna gigantea is characterized by a complex biological process involving biotic pollination and specialized fruit and seed development. The plant utilizes biotic pollination syndromes, specifically involving birds, to facilitate fertilization. Following successful pollination, the plant produces fruit in the form of a pod. These pods vary in size, with a minimum length of 10 cm up to a maximum of 15 cm, and a width ranging from 3 cm to 5 cm. The fruit is dehiscent, meaning it opens at maturity to release its contents. The seeds produced are substantial, with a minimum length of 20 mm and a maximum length of 30 mm, and a width ranging between 18 mm and 25 mm. In terms of mass, the seeds exhibit a mean weight of 3.841 g, ranging from a minimum of 2.982 g to a maximum of 4.7 g. Once released, the dispersal of the species follows a hydrochorous syndrome, utilizing water as the primary medium for transporting seeds to new locations.

Dehiscence :

dehiscent

Dispersal syndrome :

hydrochorous

Fruit length max:

15 cm

Fruit length min:

10 cm

Fruit type :

pod

Fruit width max:

5 cm

Fruit width min:

3 cm

Pollination syndrome :

bird

Pollination syndrome :

biotic

Seed length max:

30 mm

Seed length min:

20 mm

Seed mass max:

4.7 g

Seed mass mean:

3.841 g

Seed mass min:

2.982 g

Seed width max:

25 mm

Seed width min:

18 mm

Sources: Global Inventory of Floras and Traits (GIFT)

Chemicals

Mucuna gigantea has 5 reported phytochemicals identified across 0 scientific publications and several other databases. The most consistently reported chemicals include Ash, CA, FE, MG, Tannins.

Ash

1. Plant foods for human nutrition (Dordrecht, Netherlands)

CA

1. Plant foods for human nutrition (Dordrecht, Netherlands)

FE

1. Plant foods for human nutrition (Dordrecht, Netherlands)

MG

1. Plant foods for human nutrition (Dordrecht, Netherlands)

Tannins

1. Plant foods for human nutrition (Dordrecht, Netherlands)