Centrosema rotundifolium Mart. ex Benth.

Bradburya rotundifolia (Mart. ex Benth.) Kuntze
Centrosema heptaphyllum Moric.
Centrosema rotundifolium var. angustifolium Benth.

Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Phaseoleae subtribe: Clitoriinae. Also placed in: Papilionaceae.

Perennial, creeping herb, 3 (mainly) -5 leaflets/leaf, leaflets broad-elliptical to obovate, 4-35 mm wide, 6-45 mm long.  Aerial inflorescences with 2-6 violet flowers, aerial pods falcate, 25-50 mm long and 4-7 mm wide with 3-8 seeds, c. 5 mm long, 3 mm wide.
The species shows amphicarpy:  In addition to aerial peduncles and inflorescences, belowground peduncles penetrate from nodes of creeping stems into the soil, branch out and produce very small flowers from which 1- (seldom 2-) seeded pods develop.  In comparison with aerial seeds, belowground seeds are c. 40% larger and heavier.

Native to:
South America:  Brazil, Paraguay.

Long-term pasture, ground cover (erosion control, dune stabilization).

Very sandy, well drained;  medium to low fertility, acid to very acid.

800-1,200 mm/yr, 5-8 dry months.  Defoliates in dry season but regrows in rainy season.

Warm season growth only, frost tolerance unknown.

Shade tolerance unknown.

Flowering and pod setting triggered by drought stress.  Species is amphicarpic.  Belowground reproduction cleistogamous, mostly one-seeded pods, aboveground reproduction chasmogamous, 3-5 seeded pods;  100-seed weight:  7-10g.

Tolerates heavy grazing.

Regrows after fire from underground xylopodium meristems and soil seed bank.

Guidelines for the establishment and management of sown pastures.

More hardseededness in aboveground than in belowground seed;  scarification recommended.

Phosphorus for establishment recommended.

Once established, very good.

Grasses:  Brachiaria humidicola and other creeping, stoloniferous grasses.

Rhizoctonia foliar blight (occasionally).

Spread by both stolons and seed.

No information available.

Medium to high.  In 8 week old herbage (east Venezuela):  CP 22-24%, P 0.39-0.45%, Ca 0.52-0.64%.

Consumed by cattle and horses.

None recorded.

Low, e.g., in east Venezuela:  dry season, 75-184 kg/ha in 5 months;  rainy season:  2,140-2,420 kg/ha in 4 months.

No information available.

2n = 22.  Aboveground reproduction partly allogamous.

In comparison with aboveground, belowground seed production more than 3 times higher;  harvest by sieving of topsoil (first 15 cm);  yields of up to 1.5 t/ha possible.

No information available.

• Persistence under heavy grazing.
• Amphicarpy enables a continuous replenishment of soil seed bank by belowground seed production.

• Low dry matter production.
• Amphicarpic seed production constrains commercial seed production.

Rodríguez, I., Schultze-Kraft, R. and González, S. (2001) Evaluation of Centrosema rotundifolium for sand -soil savannas in Eastern Venezuela. In: Proceedings, XIX International Grassland Congress, 11-21 February 2001, São Pedro, São Paulo, Brazil. pp. 565-566.

Schultze-Kraft, R. and Clements, R.J. (eds) (1990) Centrosema: Biology, Agronomy, and Utilization. Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia.

Schultze-Kraft, R., Keller-Grein, G., Cárdenas, E. and Díaz Bolívar, F. (1994) Potencial de Centrosema rotundifolium como leguminosa forrajera. Pasturas Tropicales, 16, 2-8.

Cultivars	Country/date released	Details
None released to date.

Promising accessions	Country	Details
CIAT 5260, 5721, 25148	Venezuela	The most productive and persistent accessions.