Red Clover

Trifolium pratense L.

Family: Fabaceae.

Names:

Trifolium is from the Latin tres meaning 3 and folium meaning leaf and refers to the 3 leaflets.
Pratense means pasture referring to its traditional use as a pasture plant.
Red Clover is because it often has reddish flowers and heads.

Summary:

A large leaved, almost hairless, perennial clover with large red-purple flower heads.

Description:

Cotyledons:

Two.

First Leaves:

First leaf has only one 'spade' leaflet. Second and later leaves have 3 leaflets.

Leaves:

Trifoliate. Alternate.
Stipules - Large, 14-30 mm long. Striped near the base. Purple-red nerves. Free section is triangular with a conical or awned tip. Fused to stems at base. Fused section is papery, 12-20 mm long and egg shaped.
Petioles - Almost none near the ends of stems, longer near the base.
Blade - Of leaflets, oval, 15-55 mm long, 10-30 mm wide, often white blotched, tip is pointed or flat or slightly notched, edges smooth or extremely finely toothed. Base tapered. Almost hairless or hairless.

Stems:

Erect and drooping stems, up to 600 mm high. Almost hairless to sparsely hairy with long spreading hairs.

Flower head:

Spherical to oval, 15-35 mm long, 15-25 mm wide, appear to be at ends of branches, may have a short stalk, 2 bract-like leaves with broad stipules underneath the heads. Many flowered.

Flowers:

Many, purplish-red.
Ovary -
Calyx - Tube, 10 veined, striped, 2-3 mm long, narrow, conical, sparsely hairy on outside, densely hairy on throat and narrowed internally by a hairy ring. 5 lobes with stiff, spreading hairs, 4 lobes are narrow or bristle like, 2-4 mm long, lowest one twice as long as tube at 4-6 mm long.
Petals - Red-pink to purple petals, 10-18 mm long, narrow. Standard notched and longer than the calyx. Limb of standard narrowly egg shaped to oblong and flat topped. Keel slightly shorter than the wings with an obtuse tip.
Stamens - 10 with 9 in a group.
Anthers -

Fruit:

One seeded pods completely hidden in the persistent calyx. Top portion breaks off when ripe.

Seeds:

Flattened, egg to kidney shaped, brown, 2 mm long with a projection on one side.

Roots:

Taproot.

Key Characters:

Many flowers, all fertile with deep pinkish red petals. Calyx 10 veined, not bladdery, sparsely hairy on the outside and throat has a densely hairy ring inside. Calyx lobes filiform, not recurved, sparsely hairy. Corolla 9-17 mm long and longer than the calyx lobes. Peduncles not recurved. Flower head globular to egg shaped, 20-25 mm diameter. Pod less than 4 mm long with 1 seed and enclosed and concealed by the calyx. Leaflets elliptic, oblong to obovate, obtuse to retuse, often with a white blotch. Perennial.

Biology:

Life cycle:

Perennial. Grows mainly in autumn. Flowers late spring to early autumn.

Physiology:

Has symbiotic rhizobia in nodules on the roots that fix atmospheric nitrogen.

Reproduction:

By seeds.

Flowering times:

Summer in SA.
October to December and April in Perth.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed.

Origin and History:

European and temperate Asia.

Distribution:

ACT, NSW, QLD, SA, TAS, VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Higher rainfall areas.

Climate:

Temperate. Mediterranean.

Soil:

Plant Associations:

Significance:

Beneficial:

Fodder plant.
Used for honey and pollen production.

Detrimental:

Weed of crops.

Toxicity:

Common cause of bloat.
Hay made from Red Clover infected with Black Patch fungus (Rhizoctonia legumicola) may cause salivation syndrome in sheep and cattle.
May cause Clover Disease due to oestrogens in the plant.
May cause photo sensitisation.

Symptoms:

Clover Disease
Reduced fertility, difficult lambing, prolapse in ewes. Lactation and urinary obstructions in wethers.

Treatment:

Avoid areas infested with Black Patch when making hay.
Avoid continual grazing of areas with high proportions of Red Clover or other oestrogenic clovers.

Legislation:

None.

Management and Control:

Dicamba and sulfonylurea herbicides provide good control.

Thresholds:

Eradication strategies:

Prevent seed set for 5 years.
Exclude stock to prevent dispersal of seed and burrs.
Hand pull isolated plants in winter before flowering. For small infestations and grass dominant areas an annual application of 10 mL Tordon®75-D in 10 L water in early winter gives excellent control of existing plants and has residual activity to control seedlings.
In bushland, 200 g/ha Lontrel®750 or 50 g/ha Logran® applied in early winter provides reasonably selective control. Use 25 mL wetting agent plus 4 g Lontrel®750 or 1 g Logran® or 0.1 g metsulfuron(600g/L) or 0.1 g chlorsulfuron(750g/kg) in 10 L water for hand spraying when they are actively growing. Repeat annually for several years. Plant tall growing perennial species to reduce re-invasion.
Clovers are relatively tolerant to glyphosate, grazing and mowing.

Herbicide resistance:

Biological Control:

Related plants:

Alsike Clover (Trifolium hybridum)
Arrowleaf Clover (Trifolium vesiculosum)
Balansa Clover (Trifolium balansae)
Berseem Clover (Trifolium alexandrinum)
Birdsfoot Trefoil (Trifolium ornithopodioides)
Bladder Clover (Trifolium spumosum)
Caucasian Clover (Trifolium ambiguum)
Cluster Clover, Ball Clover (Trifolium glomeratum) is a ground-hugging plant with broad leaflets, 5-22 mm long, and globular heads of pink flowers.
Crimson Clover (Trifolium incarnatum)
Cupped Clover (Trifolium cherleri)
Drooping flowered Clover (Trifolium cernuum)
Gland Clover (Trifolium glanduliferum)
Globe Clover (Trifolium globosum)
Hop Clover (Trifolium campestre) is a sprawling plant with fairly broad leaflets, 4-15 mm long, and globular to ovoid heads of yellow flowers. The standard petal is not furrowed and it has 20-50 flowers in the head.
Hare's Foot Clover (Trifolium arvense) is an erect or sprawling plant with narrow leaflets 5-20 mm long and ovoid to shortly cylindric heads of pink flowers.
Kenya White Clover (Trifolium semipilosum)
Knotted Clover (Trifolium striatum)
Lappa Clover (Trifolium lappaceum)
Ligurian Clover (Trifolium ligusticum)
Narrow-leaved Clover (Trifolium angustifolium) is an erect plant with long narrow leaflets, 15-75 mm long, and cylindric heads of pink flowers.
Purple Clover (Trifolium purpureum)
Red Clover (Trifolium pratense)
Rose Clover (Trifolium hirtum) is a hairy plant with fairly broad leaflets, 10-25 mm long, and globular to semi-globular heads of pink to purple flowers.
Rough Clover (Trifolium scabrum)
Sea Clover (Trifolium squamosum)
Shaftal Clover (Trifolium resupinatum)
Slender Suckling Clover (Trifolium micranthum)
Star Clover (Trifolium stellatum)
Strawberry Clover (Trifolium fragiferum)
Subterranean Clover (Trifolium subterraneum) is a ground-hugging plant with broad leaflets, 6-22 mm long, and few-flowered heads of white flowers that form globular buried burrs.
Suckling Clover (Trifolium dubium) is a ground-hugging plant with loose globular heads of yellow flowers and fairly broad leaflets, 4-12 mm long and the end leaflet has a short stalk. and loose globular heads of yellow flowers.
Suffocated Clover (Trifolium suffocatum)
White Clover (Trifolium repens) is a ground-hugging plant with broad leaflets, 4-12 mm long, which often have a pale v-shaped band and globular heads of white flowers.
Woolly Clover (Trifolium tomentosum) is a sprawling plant with broad leaflets, 4-13 mm long and globular heads of pink flowers which become woolly with age.
Zigzag Clover (Trifolium medium)
Trifolium strictum

Plants of similar appearance:

Medics, Trefoils, Oxalis spp.

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P453.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P222.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P490.

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P106.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #1228.21.

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P305.

McBarron, E.J. (1983). Poisonous plants. (Inkata Press, Melbourne). P138-139. Diagram.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.