Trifolium polymorphum Poiret

Synonyms:

Trifolium obcordatum Desvaux (1814); Trifolium amphianthum Torrey & Gray (1838); Trifolium rubrum Larrañaga (1923).

Description:

Perennial, herbaceous, stoloniferous, rhizomatous, up to 40 cm long, 5-15 cm high. Flowers aerial and subterranean. Aerial flowers are auto-incompatible as well as autogamous; subterranean flowers are autogamous. Winter growth from early autumn until the end of spring when flowers/fruits and seed harvest; long summer dormancy. Next year regrows from strong roots and subterranean seeds.

Distribution:

Native of the Pampean region, Eastern Argentina, Uruguay, Southern Brazil, Paraguay, and Central Chile.

Habitat:

Grows in variable places: low humid lands up to stony dry hills; prefers meadows with low grasses, disappears in non pastured meadows due to lack of light. Great adaptability and plasticity in regards to soils: in fertile, moist soils, pH 7; in fertile, dry soils, pH 5; in deep, very fertile, permeable soils, pH 6.5; in poor, impermeable dry soils, pH 5; in sandy, permeable soils in flat areas, pH 4.75.

Use:

Low forage production but high quality and palatability, crude protein 15.2 %, P 0.18 %. Clear response to P fertilization, grows when other forages are very limited. Is favoured by grazing because does not compete with tall grasses. Persistent since growing point is below grazing line.

Nodules belong to type Rhizobium leguminosarum biovar. trifoliae (Doyle, 1998). Good nodulation with Rhizobium of Trifolium repens but not with those of Lotus, Medicago, T. subterraneum.

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