Woolly Clover

Trifolium tomentosum L.

Family: Fabaceae.

Names:

Trifolium is from the Latin tres meaning 3 and folium meaning leaf and refers to the 3 leaflets.
Woolly Clover because the seed head looks like a woolly ball.

Other names:

Fluffy Clover
Woolly-headed Clover.

Summary:

Woolly Clover is an almost hairless, low lying, trifoliate leaved annual legume with toothed leaflets, 4-13 mm long, and a cream, woolly-ball seed head produced from pink, upward facing flowers in spring.
Native to the Mediterranean region.

Description:

Cotyledons:

Two. Oval. Tip rounded. Sides convex. Base tapered to squarish. Surface hairless. Petiole longer than the blade.

First leaves:

Round with a notched base and toothed edges. Second and later leaves have 3 leaflets.

Leaves:

Alternate. 3 leaflets on short, equal length stalks at the end of the main leaf stalk (petiole).
Stipules - 5-11 mm long. Free part narrowly triangular. Fused part 2-3 mm long.
Petiole - Long. Upper leaves have shorter ones than lower leaves. Hairless.
Blade - Leaflets egg shaped to oval, 4-12 mm long x 2.5-8 mm wide. Hairless on top, hairless or sparsely hairy underneath. Tip rounded or pointed. Edges with small, spined but not prickly, curved teeth. Base tapered. Veins prominent.

Stems:

Low lying, sprawling or bending upwards, up to 300 mm long, spreading, branched. Almost hairless.

Flower head:

Globular, dense, woolly, 4-8 mm wide increasing to 12 mm when in fruit. Many flowers crowded in the head that arises from leaf axils. Heads on stalks, 5-10 mm long but very short when young and always shorter than the leaf petiole. Tiny bracts at the base of the head. At maturity the heads form woolly balls as the upper calyx lobes inflate and become papery and bladdery. Initially cream and turning brown with age.

Flowers:

Small, pink, upside down pea type. On very short stalks.
Bracts - Tiny.
Ovary -
Calyx - 2 lipped, 2-4 mm long, tubular. Tube 1-1.5 mm long with 12-13 faint veins, inner side densely hairy, outer side hairless. Throat hairless inside. Lobes are erect, narrowly triangular 1-1.5 mm long, underside of lower lobes hairless, upper side and upper lobes densely hairy or woolly. Fruiting calyx is 3-7 mm long x 3-5 mm wide, Upper lip swollen into a papery, globular bladder with a network surface to form woolly balls with 2 short teeth hidden by the wool that covers it.
Petals - Pink, 3-4 mm long, slightly longer than the calyx tube. Upside down so the standard is on the outside. Limb of standard oblong to egg shaped with a broad shallow notch at the tip. Standard petal is on the outside.
Stamens - Upper stamen free, other 9 united in an open tube. Filaments swollen towards the top.
Anthers - Uniform.

Fruit:

Small, flattened pod enclosed in the calyx. Woolly haired. Initially pinkish white and turning brown with age.

Seeds:

Brown, oval, 1 mm long.

Roots:

Have nitrogen fixing nodules.

Key Characters:

Small, annual, herbs.
Leaves with 3, digitate, denticulate leaflets.
Stipules adnate to the petiole, stipellae absent.
Flowers pink or white in dense heads.
Heads shortly pedunculate, many flowered, later forming hairy woolly or hairy balls due to inflation of upper calyx lobes which become scarious and bladdery, 4-10 mm across, not surrounded by bracts.
Calyx 12-13 nerved, hairy, gibbous with adaxial part inflated and chartaceous, persistent.
Calyx lobes of upper lip short, not protruding from the fruiting calyx.
Throat of calyx open and glabrous inside.
Fruiting calyx bladdery after flowering with 2 short upper teeth, upper lobes densely woolly or silky villous.
Upper stamen free, other 9 united in an open tube.
Staminal filaments dilated towards the apex.
Anthers uniform
Pod 1 seeded, sessile, 2 valved, dehiscent, not breaking transversely into 2 articles, enclosed in calyx.
Adapted from J.M. Black, N.T. Burbidge and J.R. Wheeler.

Biology:

Life cycle:

Annual. Seeds germinate in autumn and winter and it grows mainly in the cooler months. Flowers from September to November and dies in summer.

Physiology:

Grazing tolerant.
Waterlogging tolerant.
Moderately salt tolerant.

Reproduction:

By seed.

Flowering times:

Spring in western NSW.
September to November in SA.
September to November in Perth.
Spring in WA.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed. Woolly seed head attaches to animals and fabric for transport.

Origin and History:

Mediterranean.

Distribution:

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

Courtesy Australia's Virtual Herbarium.

Habitats:

Prefers moist areas.

Climate:

Temperate. Mediterranean.

Soil:

Red earths and duplex soils.
Common on winter waterlogged to moderately saline soils.

Plant Associations:

White Cypress Pine, Bimble Box and open woodlands.

Significance:

Beneficial:

Palatable fodder, but usually doesn't produce a large bulk of feed.

Detrimental:

Weed of crops, cultivation, pastures, lawns, gardens, turf, roadsides, woodlands, streams, granite outcrops and disturbed areas.

Toxicity:

Nor recorded as toxic.

Legislation:

None.

Management and 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, Soursob, Large flowered Wood Sorrel or Four O'clock, Oxalis spp.

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P452. Diagram.

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

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P427. Photo.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P162-163. Photo.

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). #1228.25.

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). P307.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P111. Diagrams. Photos.

Acknowledgments:

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