Aeschynomene villosa


Scientific name

Aeschynomene villosa Poir.

Subordinate taxa:
Aeschynomene villosa Poir. var. longifolia (Micheli) Rudd
Aeschynomene villosa Poir. var. mexicana (Hemsl. & Rose)
Aeschynomene villosa Poir. var. villosa

Synonyms

Aeschynomene americana L. var. villosa (Poir.) Urban
Aeschynomene decumbens Spanoghe
Aeschynomene glandulosa Bello
Aeschynomene hirsuta DC.
Aeschynomene hirta Lagerh.
Aeschynomene javanica Miq.
Aeschynomene meridana Pittier
Aeschynomene pseudoviscosa Miq.
Aeschynomene pudica Zoll. & Morren
Aeschynomene timoriana Spanoghe
Cassia tenuicaulis M.E. Jones

Family/tribe

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

Common names

villose jointvetch, hairy jointvetch, sensitive jointvetch (English);  amor seco, uekaku k'arhiri (purépecha) (Spanish - Mexico);  angiquinho, pinheirinho (Portuguese - Brazil).

Morphological description

Closely related to and morphologically very similar to Aeschynomene americana .
Annual or weakly perennial herb to sub-shrub with stems to about 1 m long, prostrate to weakly erect, glabrous to hispid.  Leaves pinnate, about 2-7 cm long, 20-50 foliolate ;  leaflets 3-15 mm long, 1-4 mm wide.  Inflorescences 3-10 (-15 flowered in var. longifolia), with hispid peduncles and pedicels;  flowers usually yellow, 3-9 mm long;  calyx 2-4 mm long, hispidstandard commonly 5-7 mm long.  Pods 3-7 (commonly 4-6) seeded, the articles 2.5-3.0 (-4) mm in diameter, villous-hispid, the tuberculate bases of the hairs often dark, in contrast with the otherwise straw-coloured or light brown fruits, usually dehiscing along the lower arcuate suture but sometimes along the transverse suture (cf. A. americana ) with seed retained in the article ;  seeds 2.0-2.5 mm long, 1.5-2.0 mm wide, dark brown to black.  Mostly about 400,000 seeds/kg, but ranging from 190,000-1,000,000 seeds/kg.

Distribution

Native to:
North America :  Mexico, USA (Arizona).
Central America :  Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama.
Caribbean:  Cuba, Dominican Republic, Guadeloupe, Haiti, Hispaniola, Jamaica, Martinique, Montserrat, Puerto Rico, St. Kitts and Nevis (St. Kitts).
South America :  Bolivia, Colombia, Ecuador, Venezuela.

Usually found in dry areas, pine and oak forests, and pastures.

Uses/applications

Primarily used as a semi-permanent or regenerating component of pasture in grazed and cut-and-carry or green chop systems.  Is showing potential as ground cover in orchard and intercrop systems, and should have application as a N fixing pioneer or green manure.  Value for standover (foggage) or hay is limited by the tendency for leaves to abscise on drying.

Ecology

Soil requirements

Occurs on sometimes poorly drained soils of clay (including cracking clay), clay loam, loam, and sandy loam texture, with pH from 4.5-8.5, (mostly 6-6.5).

Moisture

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Rainfall at collection sites ranges from 460-2,400 mm/yr, but mostly 800-1,500 mm/yr.  Tolerates waterlogging , but not to the same extent as does A. americana .  Both have the capacity to form nodules on the lower stem to offset the effect waterlogging might have on root nodulation.  Drought tolerance varies according to the degree of defoliation.  If heavily grazed adopting a rosette growth habit, it can tolerate dry conditions.  Conversely, plants entering a dry period with a bulk of foliage rapidly exhaust available moisture and show stress.  Cultivars are normally only recommended in areas receiving >1,000 mm annual rainfall , and where moisture is retained.

Temperature

Occurs from about 31.5ºN in Arizona, USA to 13.6ºS in Bolivia, and from near sea level to 2,250 m asl.  This equates to a range in average annual temperature of about 17-25º C.

Light

Grows in full sunlight and light shade.

Reproductive development

Appears to be a short day species in relation to flowering response, the critical photoperiod varying with ecotype.  Early flowering types commence flowering in late February/early March at 21ºS, while late flowering types may not commence flowering until May.

Defoliation

A. villosa is tolerant of heavy grazing, adjusting growth habit according to grazing pressure .  Under very light grazing, plants are sprawling sub-shrubs, and under heavy grazing or regular mowing, flat rosettes.

Fire

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No information available.

Agronomy

Establishment

As with most legumes, hard-seed levels of manually harvested seed are often high.  Germination is usually improved following mechanical harvesting. A. villosa is somewhat promiscuous , but nodulates most effectively if seed is inoculated with CB 2312 Bradyrhizobium or its equivalent.  Best sown into a well-prepared seedbed, but reasonable establishment can be achieved with minimum cultivation.  Seed is normally sown less than 1-2 cm deep, immediately prior to the onset of the wet season, to achieve best establishment and maximum production in the first year.  Sowing rates of 2-3 kg/ha of seed are usually adequate.  Early seedling growth is slow.
In subsequent years, regeneration occurs without further soil disturbance.  Hard seed from previous seasons becomes germinable through weathering and soil temperature effects.  The large seedling populations that develop reach an equilibrium level through natural competition and selection.

Fertiliser

Tolerates low fertility but is less productive.  Applications of 20 kg/ha P on phosphate deficient soils can produce large increases in DM yield.

Compatibility (with other species)

Once established, A. villosa is compatible with tussock and stoloniferous species.  Appears to benefit from more intensive management to minimise light competition from taller grasses.

Companion species

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Pests and diseases

Powdery mildew caused by Oidium sp., is common on undefoliated stands such as seed crops.  It forms a white mycelium on leaf surface, but, unless severe, seems to have little effect on production, quality or acceptability to animals.  In seed crops Sclerotinia-Botrytis pathogen complex sometimes causes death of stems necessitating spraying with fungicides.
Flowers and developing pods are often attacked by heliothis (Helicoverpa armigera) larvae.

Ability to spread

A. villosa spreads by seed, either by water movement or through ingestion by livestock.  Appears to be less likely to spread than A. americana or A. falcata .

Weed potential

Has shown no real indication of weediness.

Feeding value

Nutritive value

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Analysis of tip samples (terminal 15 cm) yielded the following:
Leaf: stem ratio c. 3:1.  Leaf 23-27% CP, 0.24-0.26% P, 18.3-20.7% ADFStem 9-14% CP, 0.23-0.27% P, 40.1-47.6% ADF .

Palatability/acceptability

Well eaten by livestock.

Toxicity

No record of toxicity.

Production potential

Dry matter

Capable of yields of 5-10 t/ha DM under good conditions.

Animal production

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No information available.

Genetics/breeding

2n = 20.  Off-types are rare in progeny from nursery-produced seed, where large numbers of accessions are growing in close proximity, suggesting a high degree of self-pollination .

Seed production

A. villosa exhibits 2 types of pod dehiscence - one where the arcuate suture separates at maturity, dropping the seed, and the other similar to that of A. americana where the pod breaks into segments, the seed being retained within the segment.  The latter is more easily commercially harvested.  'Reid' and 'Kretschmer' exhibit the first type, but a combination of direct and suction harvesting can produce seed yields of the order of 1 t/ha.

Herbicide effects

A. villosa is relatively tolerant of 2,4-D but not as tolerant as A. americana cvv. Glenn and Lee.  Also tolerant of 2,4-DB and MCPA.  'Reid' and 'Kretschmer' seedlings are susceptible to acifluorfen, dicamba, fluoroxypyr and metsulfuron.

Strengths

  • High quality, palatable feed.
  • Tolerant of heavy grazing.
  • Compatible with a range of grasses.
  • Good seed yields.

Limitations

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  • Not very drought hardy.
  • Susceptible to powdery mildew.

Other comments

    

Selected references

Bielig, L.M. (1997) Chromosome numbers in the forage legume genus, Aeschynomene L. SABRAO Journal, 29, 33-39.
Bishop, H.G. and Cook, B.G. (2001) Register of Australian herbage plant cultivars: Aeschynomene villosa Poir. cvv. Reid and Kretschmer. Australian Journal of Experimental Agriculture, 41, 579-580.
Kretschmer, A.E. and Bullock, R.C. (1980) Aeschynomene spp.: Distribution and potential use. Proceedings of the Soil and Crop Science Society of Florida, 39 , 145-152.
Rudd, V.E. (1955) The American species of Aeschynomene. Contributions from the United States National Herbarium, 32 , 32-37.

Internet links

Cultivars

Cultivars

Country/date released

Details

'Kretschmer'
(CPI 93621)
Australia (1995) From Veracruz, Mexico (19.5ºN, 1,420 m asl, rainfall 1,100 mm).  Perennial (to 3 or more years) to 60 cm high and 230 cm diameter.  Mature plants commence flowering 3-4 weeks later than 'Reid' at 26ºS.  'Reid' is more prostrate and has darker seeds than 'Kretschmer'.  Some propensity to form adventitious roots and plantlets on prostrate stems.  Mixed with 'Reid' and marketed as 'Villomix'.  Moderate cold tolerance.
'Reid'
(CPI 91209)
Australia (1995) From San Luis Potosí, Mexico (22.5°N, 1,250 m asl, rainfall 650 mm).  Perennial (to 3 or more years) to 30 cm high and 230 cm diameter, with darker seeds than 'Kretschmer'.  Mature plants commence flowering mid-March at 26ºS.  Some propensity to form adventitious roots and plantlets on prostrate stems.  Mixed with 'Kretschmer' and marketed as 'Villomix'.  Moderate cold tolerance.

Promising accessions

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Promising accessions

Country

Details

CPI 37235 Australia From Jalisco, Mexico (21.1ºN, 1,060 m asl, rainfall c. 1,000 mm).  Low growing, early flowering, widely adapted annual .
CPI 87491 Australia From Oaxaca, Mexico (16.3ºN, 2,000 m asl, rainfall 800 mm).  Vigorous, mid-flowering, widely adapted annual .
CPI 91219 Australia From Morelos, Mexico (19ºN, 2,100 m asl, rainfall 1,500 mm).  Vigorous, mid-flowering, widely adapted annual .