Cassia bifoliolata D.C.; C. fabiginifolia H.B.K.; C. monophylla
Vell.; Chamaecrista rotundifolia (Pers.) Greene.
Roundleaf cassia (Australia).
A herbaceous, subwoody, short-lived perennial or self-regenerating
annual legume. Stems prostrate to semi-prostrate, 30 to 110 cm long, radiating
from the root-stock, pubescent to subglabrous. Leaves bifoliate, small.
Stipules lanceolate-cordate, 4 to 11 mm long, ciliate or glabrous, up
to 1 cm long. Petiole short, 3 to 8 mm long, not exceeding the stipule,
not eglandular, pubescent like the stems. Leaflets asymmetrically subrotund
to broadly obovate, rounded apically, 0.5 to 3 cm long, sometimes ciliate,
without epetiolulates. One to two flowers, axillary, small, yellow. Pedicels
more or less filiform, 1.5 to 3.5 cm long, longer than the leaves. Sepals
lanceolate, usually ciliate, up to 5 mm long. Petals obovate, about 6
mm long, glabrous, sessile. Fertile stamens five, somewhat unequal, filaments
very short. Anthers linear-oblong, up to 2 mm long, essentially glabrous
and erostrate, dehiscent by paired terminal pores. Ovary pubescent. Pods
linear, flat, 1.5 to 4 cm long and 3 to 5 mm wide, elastically dehiscent,
blackish brown when ripe. Seeds obliquely transverse in pod, rectangular,
flattened (Woodson and Schery, 1951; Adams, 1972; R.W. Strickland, personal
Native to Florida, United States and Mexico, through Central
America south into Brazil as far as Uruguay, being widespread in northern
South America. Also found in Cuba, Puerto Rico and Jamaica. Naturalized
in parts of West Africa. Normally occurs in savannah habitats, especially
with sandy soils (Woodson and Schery, 1951; Adams, 1972).
Season of growth
The growth habit is indeterminate and growth will continue after
flowering has begun for as long as temperatures and soil moisture conditions
Early-flowering lines will grow with as little as 500 mm annual
rainfall, although more than 600 mm is desirable in Queensland, Australia
(R.W. Strickland, personal communication).
Tolerance of flooding
In studies by Whiteman et al. (19254), cv. Wynn was in the least
tolerant of four groups into which the 17 commercial legumes tested under
laboratory conditions were divided. This group died within seven to ten
days, did not develop any adventitious roots and lost all nodules when
Suited to a wide range of soils, but best adapted to light-textured
surface soils and not well adapted to clay soils, especially if inclined
to become waterlogged. In general, soil requirements are similar to those
of siratro (R.W. Strickland, personal communication).
Ability to spread naturally
Natural spread is quite rapid on suitable soils, even under
heavy grazing pressures.
Land preparation for
Under normal conditions, fully
prepared seed beds should be considered, but cv. Wynn has some ability
to establish and spread into native spear grass (Heteropogon contortus)
pastures from minimal seed beds. Seedling survival under harsh conditions
at Narayen, in south-eastern Queensland, was less than for Stylosanthes
spp., though it flowered and seeded in the first year. Townsville stylo
was the only other legume to do so. For seed production, a fully prepared
seed bed and a planting rate of 4 to 5 kg./ha are recommended (D.S. Loch,
Number of seeds per
200 000 to 470 000 (cv. Wynn 253 000).
Percentage of hard
Usually greater than 90 percent in freshly
harvested samples .
Seed treatment before
Seed should be mechanically scarified
to reduce the hard-seed level.
The only recommendations available at this stage are for seed
production stands, to which 250 kg./ha Mo superphosphate and 100 kg./ha
of m. muriate of potash are applied at planting in coastal south-eastern
Queensland, with 125 kg./ha superphosphate and possibly 50 kg./ha of muriate
of potash as annual maintenance dressings. Application of Mo at c. 100
g/ha every three years is also tentatively recommended (D.S. Loch, personal
Tolerance to herbicides
For seed production stands, trifluralin can be used before planting,
while bentazone (3 litres/ha of 48 percent product) and dinoseb (4 litres/ha
of 20 percent product) appear safe for post-emergence use. Acifluorfen,
2,4-D and 2,4-DB have caused crop damage on cv. Wynn and should not be
used. Fluazifop (1 to 2 litres/ha on 21.2 percent product) appears likely
to control grass weeds in seed crops (D.S. Loch, personal communication).
Response to defoliation
Cv. Wynn is essentially prostrate; it therefore seems likely
that it will withstand fairly heavy grazing, certainly heavier grazing
C. rotundifolia is fairly tolerant of a wide range of management
regimes and styles. However, care will need to be taken that vigorous,
tall-growing grasses and weeds arc not allowed to dominate the lower-growing
Dry-matter and green-matter
Annual dry-matter yields of more than
7 000 kg./ ha have been recorded at Beerwah and Gatton, those at Beerwah
with cv. Wynn being double the yields of greenleaf desmodium (Desmodium
intortum) and siratro in spring and early summer. Later in the season,
yields were equal to those of the standard cultivars (R.W. Strickland,
Six accessions of C. rotundifolia have been tested on a rat
colony at the Commonwealth Scientific and Industrial Research Organization
(CSIRO), Samford, south-eastern Queensland, and showed no signs of toxicity.
Live-weight gains and digestible dry-matter intakes up to 14 percent higher
than with the lucerne (Medicago sativa) controls have been recorded. Seeds
fed gave approximately 80 percent of the weight gains of the control,
autoclaved soybean meal (R.W. Strickland, personal communication).
Seed harvesting methods
C. rotundifolia is suitable for normal, direct-header harvesting.
Using this method, two harvests per year should be possible. Unless flowering
ceases owing to moisture stress, timing of each harvest does not seem
critical, as crops flower continuously and standing seed yield will remain
near the peak for prolonged periods, the loss of seed from shattering
pods being offset by new pods entering the system (D.S. Loch, personal
At present there is no commercial experience, but yields in
excess of 800 kg./ha from two harvests in one season have been obtained
at Beerwah from small plots. Lower yields of only 200 kg./ha, from single
harvests at Grafton, New South Wales, and Narayen, have also been recorded
(R.W. Strickland, personal communication).
The only cultivar released to date is Wynn, derived from introduction
CPI 34721, from Valinhos in Brazil. Released by the Queensland Herbage
Plant Liaison Committee in August 1983, it is an early-flowering type,
reaching peak flowering in January. The CSIRO collection can be divided
into four maturity groups, the latest not flowering until April/May in
southern Queensland and unlikely to complete seed set before the onset
of frosts in that environment (R.W. Strickland, personal communication).
It is likely that a mid-season type will also be released.
To date, the only known disease attack was a minimal leaf spotting
caused by Pleospora sp. at Gympie, Queensland. This is unlikely to cause
any concern under grazing conditions.
With widespread adaptation to lighter-textured, more acid soils
and a fair tolerance to heavy grazing, cv. Wynn appears likely to complement
siratro in southern Queensland and possibly to extend into somewhat drier
Restriction to lighter-textured soils.
It does not require specific rhizobia, nodulating readily with
native rhizobia in Queensland soils.