Chamaecrista rotundifolia


Scientific name

Synonyms

Cassia rotundifolia Pers.

Family/tribe

Family: Fabaceae (alt. Leguminosae) subfamily: Caesalpinioideae tribe: Cassieae subtribe: Cassiinae. Also placed in: Caesalpiniaceae.

Common names

round-leaf cassia; round-leafed cassia.

Morphological description

Chamaecrista rotundifolia is a short-lived perennial or self-regenerating annual herb, sub-woody, semi-erect, growing to 1 m tall, with a shallow taproot.  Stems pubescent to subglabrous, 45-110 cm long.  Leaves bifoliolate.  Stipules lanceolate-cordate 4-11 mm long, petioles 3-8 mm long, eglandular.  Leaflets 2, asymetrically subrotund to broadly obovate, rounded apically, 12-38 mm long, 5-25 mm wide.  Flowers 1-2 (-3) axilliary, small yellow.  Sepals lanceolate, usually ciliate, up to 5 mm long.  Petals obovate, up to 6 mm long, glabrous, sessile.  Fertile stamens 5, somewhat unequal, filaments very short.  Anthers linear oblong, up to 2 mm long, essentially glabrous and erostate, dehiscent by paired terminal pores.  Ovary pubescentPedicel more or less filiform, 14-78 mm long.  Pod linear, 20-45 (-60) mm long, 2.5-5.0 mm wide, flat, elastically dehiscent , seeds obliquely transverse.  Seeds rectangular, flattened, 2-3 mm long.  200,000-470,000 seeds/kg.
Cv. Wynn has broad leaflets, 15-22 mm wide, long pods, 38-40 mm long, and small seeds (253,000/kg).

Distribution

Native to:
North America:  Mexico.
Mesoamerica:  Costa Rica, Honduras, Panama.
Caribbean:  Cuba, Jamaica, Puerto Rico.
South America:  Argentina (north), Bolivia (east), Brazil, Colombia, Ecuador, Guyana, Paraguay, Uruguay, Venezuela.

Naturalised in west Africa and USA.

Uses/applications

Sown into native pastures to augment feed quality and occasionally sown into pastures of improved grasses.  Limited value for conservation or standing hay because of substantial leaf drop under dry conditions, leaving woody indigestible stem .  Has been made into good quality 'haylage' by baling Digitaria milanjiana / cassia herbage at 40% moisture content and wrapping in plastic sheets.  Has been successfully trialled for use in cut-and-carry systems in southern China, and for use as a ley or phase legume in crop-livestock systems in Nigeria where its use resulted in improved cereal production.

Ecology

Soil requirements

Free-draining light soils of low to moderate fertility.  New accessions from Brazil can tolerate acid soils and high Al saturation.  Most accessions have been collected from acid soils, but a small number originate from neutral or slightly acid soils.  Very well adapted to acid infertile red soils of central southern China.

Moisture

Top

Behaves as a perennial under 900-1,500 mm rainfall;  as an annual down to 600 mm.  One of the best adapted legumes on sandy soils in semi-arid northern South Africa and in semi-arid west Africa.  Does not tolerate poor drainage or flooding.  Reasonably drought-tolerant when plants form rosettes under heavier grazing, but leaves often turn red and drop if plants are left ungrazed and tall during dry conditions.  Has been collected from sites with rainfall ranging from 400-3,700 mm, but most are in the 800-1,500 mm range.

Temperature

Warm season growth only;  top growth readily killed by frost.  Under regular heavy frosts, round-leaf cassia behaves as an annual .  There were large differences among accessions in survival over winter in subtropical China (26-29ºS).  Only those from the most extreme southern origins (Paraguay and Argentina) survived.

Light

Full sunlight to moderate shade.

Reproductive development

Cv. Wynn flowers early in the season and then continues over a long period.  Strong relationship between the latitude of provenance and flowering date, growth and canopy height.  Accessions from low latitudes tend to be late flowering and tall;  those from higher latitudes are earlier flowering and smaller.  Soil seed reserves can reach 1,000-1,200 seeds/m2 .

Defoliation

Very tolerant of constant heavy grazing;  however, if allowed to grow tall and then cut low, individual plants fail to regenerate, but populations will regenerate from seed.

Fire

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Some plants persist but most regeneration is primarily from soil seed reserves.

Agronomy

Establishment

Although there have been reports of high levels of hard seed, mechanically harvested seed rarely requires further scarification.  However, seed must not be treated with hot water to break dormancy as it becomes mucilaginous.  Seed germinates quickly after rainfall;  seedlings grow rapidly and early-flowering types can flower within 6 weeks.  Round-leaf cassia appears to nodulate readily with native rhizobia.

Fertiliser

Responds to phosphorus and sulphur on low-fertility soils.

Compatibility (with other species)

Combines well with native tussock grasses and more open creeping naturalised grasses, but can become dominant if stock concentrate on more palatable companion grasses in early and mid-growing season .  Can improve the protein level of associated grasses.

Companion species

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Pests and diseases

No known insect attack or serious fungal disease in Australia.  Anthracnose (Colletotrichum spp.), foliar spots (Phomopsis spp.) and foliar blight (Rhizoctonia solani) seen in Central and South America.  Anthracnose has been very destructive on new accessions in the Brazilian savannas.  Foliar blight is more serious in regions receiving 2,000 mm AAR .  Recorded as a host for alfalfa mosaic virus in Africa and some accessions attacked by anthracnose in West Africa.  Recent studies in the USA have shown the species is more susceptible to a wider range of fungal pathogens than was first realised.

Ability to spread

Will spread naturally through heavy seed set.

Weed potential

Massive seed set and low seasonal palatability tend to suggest this plant could have some weed potential.

Feeding value

Nutritive value

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Nutritional value as good as Medicago sativa in rat-feeding trials.  Good protein and digestibility levels recorded under grazing.  Application of deficient P and S in southern Queensland increased N concentrations of leaf tips to 3.3% N.
'Wynn' cassia raised N concentrations of companion native grass (Heteropogon contortus ) by 20-40% under grazing and fertilising (with P & S).

Palatability/acceptability

Generally not eaten readily by cattle in the growing season under higher rainfall conditions, but becomes more acceptable as the associated grasses mature later in the season.  Can comprise up to 20% of diet in late autumn.
Little apparent problem with 'Wynn' cassia in drier areas (<900 mm) but late maturing, tall types can be rejected by stock.  Not eaten by horses.

Toxicity

No known anti-nutritional factors in C. rotundifolia , but C. trichopoda toxic to rats in laboratory trials.

Production potential

Dry matter

DM yields of up to 7,000 kg/ha recorded in south-east Queensland.

Animal production

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In Australia, oversowing cv. Wynn into native pasture of Heteropogon contortus increased LWG /head of steers stocked at 2.4 ha/head by 34 kg/yr (40% improvement) or by 45 kg/yr when fertilised with P and S.

Genetics/breeding

  

Seed production

Very heavy seed set, but seed ripens over an extended period and shatters.  Yields of 800 kg/ha have been collected under suction harvesting in Australia.

Herbicide effects

Susceptible to 2,4 -D and to aciflourfen;  moderately tolerant of fluazifop-butyl and sethoxydim.

Strengths

  • Rapid establishment and spread.
  • Low fertility demand.
  • Adapted to acid soils.
  • High seed yields.

Limitations

Top

  • Low palatability .
  • Poor drought tolerance if ungrazed.
  • Susceptible to anthracnose in the South American savannas.

Other comments

Palatability can be a major problem in many Chamaecrista spp., although C. nicitans is claimed to be very palatable.

Selected references

Hacker, J.B., Wen Shilin, Ying Zhaoyang and Pengelly, B.C. (2001) Selecting Chamaecrista spp. for stabilisation and forage in southern China. Tropical Grasslands, 35, 96–113.
Jones, R.M. (1992) Chamaecrista rotundifolia (Persoon) Greene. In: 't Mannetje, L. and Jones, R.M. (eds) Plant Resources of South-East Asia No. 4. Forages. pp. 88-89. (Pudoc Scientific Publishers, Wageningen, the Netherlands).
Lenne, J.M. and P. Trutmann, P. (1994) (eds) Diseases of Tropical Pasture Plants. (CABI, Wallingford, UK).
Partridge, I.J. and Wright, J. (1992) The value of round-leafed cassia (Cassia rotundifolia cv. Wynn) in a native pasture grazed with steers in south-east Queensland. Tropical Grasslands, 26, 263–269.
Pengelly, B.C., Maass, B.L., Thomas, B.D. and Hacker, J.B. (1997) Origin of the world’s collection of the tropical forage legume Chamaecrista rotundifolia . Proceedings of the VXIII International Grassland Congress, 8-19 June 1997, Winnipeg, Manitoba, and Saskatoon, Saskatchewan, Canada, vol. 1(1), 25–26.
Strickland R.W., Greenfield, R.G., Wilson, G.P.M. and Harvey, G.L. (1985) Morphological and agronomic attributes of Cassia rotundifolia Pers., C. pilosa L., and C. trichopoda Benth., potential forage legumes for northern Australia. Australian Journal of Experimental Agriculture, 25, 100–108.
Tarawali, S.A. (1994) The yield and persistence of selected forage legumes in subhumid and semi-arid west Africa. Tropical Grasslands, 28, 80–89.
Tarawali, S.A. (1995) Evaluation of Chamaecrista rotundifolia accessions as a fodder resource in subhumid Nigeria. Tropical Grasslands, 29, 129–133.
Tarawali, S.A. and Peters, M. (1996) The potential contribution of selected forage legume pastures to cereal production in crop-livestock farming systems. Journal of Agricultural Science, 127, 175–182.

Internet links

Cultivars

Cultivars

Country/date released

Details

'Wynn'
(CPI 34721)
Australia (1984) Provenance - Valinhas, Brazil.

Promising accessions

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Promising accessions

Country

Details

CPI 85836, CPI 92931, CPI 86172, CPI 93094 Australia Later flowering and taller types than cv. Wynn.
Q 9862, Q 10057 Australia Very late flowering.
ATF 2228, ATF 2230, ATF 2231 China Better cold-tolerance, early-flowering types which originate from Argentina and Paraguay.  Higher winter survival made these most promising for soil stabilisation in orchards in red soils region of southern China.
ATF 3203, ATF 3253, CPI 86134 China High yielding for annual cut-and-carry systems but low winter survival on red soils of southern China.
CPI 86134 China Rapid establishment on red soils in Fujian and Hunan Provinces.
ILCA 14165, ILCA 14167 Nigeria - subhumid For yield and quality;  ILCA 14167 most promising.
ILCA 14172, ILCA 14174 Nigeria - subhumid For dry season production.
BRA 000183, BRA 000205 Brazil For acid, low fertility soils (Oxisols).
CIAT 8156, CIAT 8158, CIAT 8391, CIAT 8992, CIAT 17000, CIAT 17001 Columbia For very acid, high Al soils.
CIAT 7792 Brazil Highest DM yields in humid tropics.