Mucuna gigantea – Seabean

Mucuna gigantea - Seabean, Sea Bean (green flowers)

Mucuna gigantea - Seabean, Sea Bean (flowers and leaves)

Mucuna gigantea - Seabean, Sea Bean (bean pods)

Mucuna gigantea - Seabean, Sea Bean (seeds)

Mucuna gigantea - Seabean, Sea Bean

Plant Name

Scientific Name: Mucuna gigantea

Common Names: Seabean, Sea Bean

Plant Characteristics

Duration: Perennial

Growth Habit: Vine

Hawaii Native Status: Native (indigenous)

Flower Color: Lime green to yellowish green, Greenish white

Height: Up to 50 feet (15 m) long

Description: The flowers are in pendent, round-topped, umbel-like clusters. The individual flowers are pea-like with a bent, upcurved keel. The flowers are followed by oblong, flattened, winged, green drying to dark brown bean pods lightly covered in stinging, orange-brown hairs known as trichomes. The seeds resemble hamburgers due to their disk shape and indented, black hilum (seed scar) and are almost 1 inch (2.5 cm) wide and brown, mottled brown and black, or solid black in color. The leaves are trifoliolate with 3 green, hairless or mostly hairless, broadly elliptic to egg-shaped leaflets. The stems are slender and twining. The vines typically hang down from the trees in green, leafy curtains.

The hard, woody seeds are polished and made into attractive necklaces and leis.

Seabean vines grow at lower elevations, usually near the coast. The seeds can be carried great distances by the ocean currents and still remain viable, which is how they ended up here in Hawaii.

The similar Horseeye Bean (Mucuna sloanei) has yellow flowers and bean pods with transverse ridges, while Cowitch (Mucuna pruriens) has white and dark purple flowers and much hairier bean pods.

Special Characteristics

Poisonous – The seeds are poisonous and contain L-DOPA and other potentially toxic substances. Although L-DOPA is used to treat Parkinson's disease, ingestion of large quantities can cause gastrointestinal symptoms like nausea and vomiting and severe mental symptoms like psychosis, paranoid delusions, and hallucinations.

Classification

Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Magnoliopsida – Dicotyledons
Subclass: Rosidae
Order: Fabales
Family: Fabaceae – Pea family
Genus: Mucuna Adans. – mucuna
Species: Mucuna gigantea (Willd.) DC. – seabean

More About This Plant

Hawaii County Distribution Map