Centro, Butterfly pea
Centrosema pubescens

Family: Fabaceae

What it is like

Centrosema pubescens is an evergreen Perennial Climber growing to 0.5 m (1ft 8in) by 0.5 m (1ft 8in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10. It can fix Nitrogen. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers moist or wet soil and can tolerate drought.

Height (m): 0.5

Where it is found

Naturalized along roadsides, in waste places, on river banks and on coconut plantations at elevations near sea level.

S. America and Central America.

Conservation Status: This taxon has not yet been assessed

Countries/locations it is found in

How it is used

Food

Rating: 0

Medicine

Rating: 0

Other

Rating: 3

Agroforestry Uses: The plant is grown as a green manure in some parts of the tropics. Centro has been used as a green manure and plantation ground cover in Java and Peninsular Malaysia since the 19th century. It is widely used as a plantation cover and/or pasture legume in South-East Asia, the Pacific Islands, the wet tropics of Australia and indeed much of the humid tropics worldwide It is an efficient fixer of nitrogen, with concentrations generally ranging from 2.4 - 2.7%.

Fodder: Food given to the animals (including plants cut and carried to them) rather than forage for themselves.

Agroforestry Services: Nitrogen: Plants that contribute to nitrogen fixation include the legume family – Fabaceae.

Agroforestry Services: Understory legume: Legume vegetation, especially the trees and shrubs growing between the forest canopy and the forest floor.

Fodder: Pasture: Enclosed tracts of farmland mainly of grasses, with an interspersion of legumes and other forbs (non-grass herbaceous plants).

Management: Fodder: Non-destructive management systems maintaining the soil organic carbon.

Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.

Agroforestry Services: Nitrogen: Plants that contribute to nitrogen fixation include the legume family – Fabaceae.

Agroforestry Services: Understory legume: Legume vegetation, especially the trees and shrubs growing between the forest canopy and the forest floor.

Fodder: Pasture: Enclosed tracts of farmland mainly of grasses, with an interspersion of legumes and other forbs (non-grass herbaceous plants).

Management: Fodder: Non-destructive management systems maintaining the soil organic carbon.

Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.

Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.

How it is grown

A plant of the moister tropics. It prefers an annual rainfall of 1,500 mm or more but plants have persisted in pastures receiving an average annual rainfall of only 800 mm. It can survive a 3 - 4 month dry season but is not adapted to prolonged drought. It is intolerant of low temperatures, growing poorly when they fall below 15?c. Tolerant of waterlogged conditions. Plants are shade tolerant, and can persist even with shade levels as high as 80%. The plant produces large quantities of viable seeds. It has escaped from cultivation and become established in the wild in some areas. It forms dense mats of growth on the ground, and also climbs onto trees. It is a vigorous plant that invades disturbed areas, choking out more desirable species - often the tree layer is destroyed and regeneration of native species is prevented. Centro is notoriously slow to establish and requires good conditions during the establishment period, but when grown in a pure sward it forms a dense, compact cover 35 - 45 cm deep, 4 - 8 months after sowing. It is fully established and vigorous by at least the 2nd year. In ungrazed mixtures with Panicum maximum, it forms an impenetrable vine canopy some 2 metres high. In a mixture with calopo (Calopogonium mucunoides) and puero (Pueraria phaseoloides), centro persists longest under the closing canopy of plantation crops. In the humid tropics, the preferred legumes for fertile and infertile soils have traditionally been centro and stylo (Stylosanthes guianensis) respectively. However, when soil mineral deficiencies are corrected and seed is inoculated with an effective bacteria, centro has been more productive than stylo on all land classes. Centro combines well with other species in mixed pastures or ground covers under plantation crops. Trailing runners have a tendency to root at the nodes if soil moisture is high, giving the plant a stoloniferous appearance. Pure stands of centro have produced DM yields of up to 12 tonnes per hectare per year. This species has a symbiotic 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. Nodulation occurs with a range of rhizobia but optimal growth has been achieved with very few strains. Inoculation with an effective strain of Bradyrhizobium is, therefore, recommended. Estimates of nitrogen fixation range from 120 - 270 kg/ha per year.

Propagating it: Up to 60% of the seed has a hard coat and will germinate better if some form of scarification is used. On a domestic scale this is most easily carried out by immersing the seed in a small quantity of very hot water for a few minutes and then leaving the seed in warm water for 12 - 24 hours before sowing. Other methods include chipping a small part of the seed case near the embryo, being very careful not to damage the seed, or, on a commercial scale, a short immersion in sulphuric acid. Seeding rate is about 5 kg/ha. Full seed-bed preparation and careful crop planting procedures are generally recommended, especially since centro is somewhat slow to establish. However, centro has been successfully sod-seeded directly into a run-down grass pasture, following heavy grazing and low slashing of the residual grass.

Best place to grow:

Habit: Perennial Climber

Hardiness: 10-12

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: Full shade, semi-shade, no shade

Moisture: Moist, wet

Things to keep in mind

A vigorous plant that invades disturbed areas, choking out more desirable species - often the tree layer is destroyed and regeneration of native species is prevented.

Its other names

Local names

Synonyms

Centrosema molle Mart. ex Benth.