Birdsfoot trefoil because the pods are attached to a common point and look like a birds foot.
Summary:
A leguminous, annual to perennial herb with trailing-ascending stems to 0.75 m tall. It has 10 mm long, bright yellow, and sometimes tinged with red, pea type flowers in clusters of 3-12 attached to a common point. These produce 25 mm long, narrow, cylindrical pods in clusters that resemble a birds foot. The hairy leaves have three, clover like leaflets at the top and 2 more leaflets at the base of the petiole and somewhat stem clasping.
It is native to Europe and has become a weed along roadsides, in damp pastures and particularly along creeklines. It flowers in spring and summer.
Description:
Cotyledons:
Two.
Leaves:
Made up of 5, leaflets, 3 at the tip of the leaf stem, 2 smaller ones at the base which are modified stipules.
Stipules - Look like leaflets at the base of the petiole and are smaller than trifoliate leaflets.
Petiole - Yes.
Blade - Of trifoliate leaflet, smooth edged, blunt, egg shaped, 3-10 mm long, and may have a stiff point(mucro) at the apex.
Stems:
Slender, low lying or bending upwards at the ends, mainly solid but often with hollow sections. Hairless to very hairy.
Flower head:
2-12 flowers in an umbel on stalks (peduncles) 2-3 times longer than the leaf.
Flowers:
Pea-like, 10-15 mm long. Often marked with red veins. 10-15 mm long.
Bracts - 3 broad leaf bracts at the top of the peduncle.
Ovary -
Calyx - 7 mm long with erect teeth as long as the tube. Smooth or slightly hairy
Petals - Yellow. Keel petal the same length as the standard and bent at right angles. Standard twice as long as the calyx.
Stamens -
Anthers -
Fruit:
Cylindrical, straight pod, 20-30 mm long by 2 mm diameter that darkens on maturity. Valves twist spirally when ripe.
Seeds:
Many, smooth, globular.
Roots:
Taproot
Key Characters:
2-12 yellow flowers on peduncles that are longer than the leaf in an umbel. Perennial.
Biology:
Life cycle:
Annual or Perennial.
Physiology:
Reproduction:
By seed.
Flowering times:
Flowers in summer in SA.
Seed Biology and Germination:
Vegetative Propagules:
Hybrids:
There are over 25 commercially available cultivars.
Allelopathy:
Population Dynamics and Dispersal:
Spread by seed.
Origin and History:
Europe and Asia. Some forms often regarded as being native.
Distribution:
ACT, NSW, QLD, SA, TAS, VIC.
Widespread in eastern Australia.
Courtesy Australia's Virtual Herbarium
Habitats:
Climate:
Temperate.
Soil:
Plant Associations:
Grassy areas.
Significance:
Beneficial:
Fodder. Soil stabiliser on roadsides.
Detrimental:
Weed of roadsides and wastelands.
It can form thick mats choking out most other plants.
Toxicity:
May cause cyanide poisoning. Some varieties of the plant have are more toxic than others.
Symptoms:
Cyanide poisoning.
Treatment:
Legislation:
None.
Management and Control:
Don't burn as this tends to make the infestation worse.
Mowing to 50 mm every three weeks provides control in roadside situations.
Thresholds:
Eradication strategies:
Mowing to 5 cm every 3 weeks provides reasonable control. Don't burn infested areas. Improve drainage to reduce water logging during winter. Herbicides provide the most effective control. Use picloram based products such as 100 mL Tordon®75-D plus 25 mL wetting agent in 10 L water in grass dominant situations or on small infestations. Use 60 g/ha Logran® or 200 g/ha Lontrel®750 for reasonably selective control in native vegetation. For hand spraying mix 25 mL wetting agent plus 1 g Logran® or 4 g Lontrel®750 in 10 L water and apply in winter to early summer when actively growing. 0.1 g metsulfuron(600g/kg) plus 25 mL wetting agent in 10 L water also provides good control but may damage young native species at these rates. Glyphosate is not very effective. Grazing generally provides little control. Cultivation tends to make infestations worse. Replant native trees and shrubs to increase shade.
Herbicide resistance:
Biological Control:
Related plants:
Australian trefoil (Lotus australis) is very similar but has pink or white flowers.
Greater Lotus (Lotus uliginosus) has clusters of up to 15 flowers, each 9-15 mm long, and the seed pods that are 1.5-3.5 cm long.
Hairy Birdsfoot Trefoil or Boyds Clover (Lotus suaveolens) has flowers 6-9 mm long and seed pods that are 0.5-1.5 cm long.
