Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Dalbergieae.
Perennial herb, with stems ascending to erect, to 60 cm tall, branched, largely glabrous. Leaves bifoliolate, glabrous or puberulent; lower leaflets lanceolate, acute to 40 mm long, 8 mm broad; the upper leaflets narrower, usually punctate, glabrous above, glabrous or strigose below. Inflorescence a congested axillary spike; bracts lanceolate-ovate, acute, to 10 mm long, 4 mm broad, with short-acuminate auricle to 1 mm long, punctate, glabrous, sparsely ciliate; calyx to 4 mm long, largely glabrous; standard to 13 mm long, lemon yellow with red striations at the base. Loment with 5–7 articles, 2.0–2.5 mm long, 2.0 mm wide, 2.0 mm broad, with numerous retrorsely hairy bristles to 1.2 mm long. 650,000‒1,000,000 seeds per kg.
Latin America: mariguana del Brasil, zornia (Brazil); alverjilla, cargadita, encarrugada, urinaria, zarzabacoa de dos hojas, zornia (Spanish)
Note: Many Zornia spp. have bifoliolate leaves and have been classified as or confused with Z. diphylla. The above common names have been associated with Z. diphylla.
South America: Brazil, French Guiana, Guyana, Suriname
Occurs on ultisols in its native environment, and has proven adapted to ultisols and oxisols in the wet tropics elsewhere. These soils have pH as low as 4, and are of low fertility.
Collection and evaluation data show is adapted to the humid and moist subhumid tropics, in areas with average annual temperatures ranging from about 23 to 27 ºC.
Little or no shade tolerance.
Occasionally observed flower colour segregation suggests outcrossing potential. Free-seeding.
Recovers from soil seed bank and below-ground crown.
Seed sown at 2–3 kg/ha. Reported to nodulate readily with native rhizobia.
Responds to applications of P, K, and S at 20, 20 and 10 kg/ha and FTE on infertile soils.
Compatible only with (low-growing) bunch grasses.
Grasses: Andropogon gayanus, Megathrysus maximus
Legumes: Not generally sown with other legumes.
Resistant to scab caused by the fungus, Sphaceloma zorniae, which causes scab lesions on leaves, petioles and stems, and eventually dieback, in other Zornia spp.; susceptibility to bacterial wilt caused by Corynebacterium flaccumfaciens has been reported.
Good natural spread by self-sown seed.
Considered to be low; easy to control by herbicides.
Moderate DM yields in savanna climates (2‒2.5 t/ha/season).
No information available.
Probably 2n = 20, as with other Zornia spp. assessed.
Prolific seeder but no hard data available.
No information available.
Cadisch, G., Sylvester-Bradley, R. and Nösberger, J. (1989) 15N-based estimation of nitrogen fixation by eight tropical forage-legumes at two levels of P:K supply. Field Crops Research 22:181–194. doi.org/10.1016/0378-4290(89)90091-9
Pizarro, E.A. (ed). (1992) Red Internacional de Evaluación de Pastos Tropicales RIEPT, 1a. Reunión Sabanas, 23–26 de noviembre de 1992, Brasília, Brasil. Documento de trabajo No. 117. CIAT, Cali, Colombia. hdl.handle.net/10568/56399
Schultze-Kraft, R., Lascano, C., Benavides, G. and Gómez, J.M. (1989) Relative palatability of some little-known tropical forage legumes. Proceedings of the XVI International Grassland Congress, Nice, France, 4–11 October 1989. pp. 785–786.
CIAT 7847 Good performance reported in the Philippines, Llanos Orientales (Colombia), and Corrientes Province (NE Argentina). Agronomic evaluation on low pH (<5) oxisols. In Argentina, DM yields were reported as being comparable to those of Stylosanthes capitata.
CIAT 8279 and CIAT 8283 Evaluation in Colombia determined that performance of these two accessions was similar to that of CIAT 7847 (see above).