Crimson Clover

Trifolium incarnatum L.

Family: Fabaceae.

Names:

Trifolium is from the Latin tres meaning 3 and folium meaning leaf and refers to the 3 leaflets.
Incarnatum
Crimson Clover because it has pink or crimson flower heads and belongs to the clover genus.

Other names:

Summary:

An erect, furry, usually unbranched, trifoliate legume with red, oval to cylindrical flower heads.

Description:

Cotyledons:

Two. Oval. Hairless.

First leaves:

First leaf has only one leaflet. Second and later leaves have 3 egg shaped leaflets.

Leaves:

Alternate with 3 diamond shaped leaflets on equal length stalks.
Stipules - 12-20 mm long. Dry and membranous, green veins, partly joined to the petiole. The free part short, egg shaped, .with a dark red to green tip.
Petiole - Long.
Blade - Of leaflet, broadly egg shaped with tiny teeth near the tip. 8-35 mm long x 7-26 mm wide with a rounded or slightly notched tip. Softly hairy.

Stems:

Stem usually single and unbranched, rather stout, erect or spreading. 200-500 mm tall.

Flower head:

Red. Oval shaped initially and becoming cylindrical at maturity, 20-62 mm long x 11-20 mm thick, on long rather stout stalks at the ends of stems.

Flowers:

Red, pea type, stalkless.
Ovary -
Calyx - 8-10 mm long, furry. 10 veined, tubular, with 5, almost equal lobes.
Lobes longer than the tube, 5-6 mm long, narrow and tapering to a fine point and become stiff and spreading when in fruit. Tube 2.4-4 mm long. Throat slightly thickened and hairy inside.
Petals - Red or rarely white, 10-14 mm long, scarcely longer to much longer than the calyx. Limb of standard oblong.
Stamens - 10 with 9 in a group.
Anthers -

Fruit:

Pod is hidden in the persistent calyx. Pod with 1 (or rarely 2) seeds. Doesn't release seed.

Seeds:

Brown, oval ~2 mm long.

Roots:

Has nodules for fixing Nitrogen.

Key Characters:

Annual.
Stem usually single and unbranched, rather stout.
Leaflets obovate.
Flower heads pedunculate, oval and finally cylindrical.
Peduncles not curved
Flowers all fertile, many in the head.
Calyx villous, 10 veined, not inflated, enclosing and concealing the pod.
Calyx lobes (teeth) 5-6 mm long, subulate, plumose, rigid and spreading in fruit.
Calyx throat slightly thickened and hairy inside.
Corolla 9-17 mm long, as long or longer than the calyx lobes.
Standard equalling or exceeding the calyx.
Pod with 1 (or rarely 2) seeds up to 4 mm long.
Adapted from John Black and Judy Wheeler.

Biology:

Life cycle:

Annual. Seeds germinate in autumn and winter. Flowers from September to December.

Physiology:

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

Reproduction:

By seed.

Flowering times:

Spring to summer in WA.
October to November in Perth.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Origin and History:

Europe.
Introduced as a pasture species.

Distribution:

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

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate. Mediterranean

Soil:

Sandy to loamy red earths. Duplex soils.

Plant Associations:

Jarrah, red gum and a range of other wood land communities.

Significance:

Beneficial:

Palatable fodder.

Detrimental:

Weed of crops, roadsides, parklands, recreational areas, lawns, gardens and disturbed areas.

Toxicity:

Not recorded as toxic.

Symptoms:

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:

Very similar to Narrow leaved Clover (Trifolium angustifolium) but differs in its leaves.
Medics, Trefoils, Oxalis spp.

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P454. Diagram.

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

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

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

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #1013.13.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P304.

Acknowledgments:

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