An erect, leguminous plant with 1-3 pairs of leaflets, no tendrils. white flowers with dark markings and large pods and seeds. Plants turn black when mature.
Description:
Cotyledons:
Two. Underground. Kidney to round shape. Large. Hairless.
First leaves:
Have a short spear shaped tendril at the tip and a pair of oval leaflets. Leaflets are shiny and somewhat leathery with a pointed, flat or indented tip, undulating edges and tapered base. Hairless.
Leaves:
Alternate. Green and turn black when mature.
Almost hairless. No tendrils.
Stipules - 3 lobed with toothed or smooth edges. Lobes often with a dark marking.
Petiole - of leaf is shorter than the leaf. Leaflet petiole almost none.
Blade - 1-3 pairs of often alternate leaflets often with a terminal leaflet. Leaflets oval, 40-80 mm long.
Stems:
Erect, round to square, almost hairless. Up to 1200 mm tall. Turn black when mature.
Flower head:
Shorter than the leaves. 1-6 flowered. On a short stalk. In leaf axils.
Flowers:
White with black or dark markings. Pea type. On stalks, 2-3 mm long.
Ovary - Style filiform, bearded in upper part.
Calyx - Tubular. Swollen at the base. Lower teeth shorter than the tube. Upper teeth shorter than the lower ones.
Petals - White or tinged with red to purple. Black stripes, 20-30 mm long Petals - Black spots on wings. Limb of standard petal greater than or equal to the length of the claw.
Stamens - 10, upper stamen free, other 9 united in an open tube, staminal tube oblique at the top.
Anthers -
Fruit:
Brown, long pod, cylindrical or somewhat flattened. 2 valved with dense furry hairs initially and becoming sparsely furry when mature. Up to 200 mm long with a 1-8 seeds. Constricted between the seeds when mature. Turn black when mature.
Seeds:
Shiny brown with a black stripe (hilum), fattened, oblong to egg-shaped, 8-30 mm long. Yellow flesh when split.
Roots:
Taproot. Nitrogen fixing nodules.
Key Characters:
Erect herb.
Leaves divided into 1-3 pairs of leaflets, paripinnate, ending in a fine point.
Stems terete to angular or square.
Flowers very irregular(zygomorphic), petals unequal, more or less united, the upper one(standard) outside the others in bud.
Style filiform, bearded in upper part.
Stamens 10, upper stamen free, other 9 united in an open tube, staminal tube oblique at summit.
Pod compressed, 2 valved, dehiscent, not breaking transversely into articles.
Seed large.
Embryo curved.
From J.M. Black.
Biology:
Life cycle:
Annual. Seed germinates at any time of year moisture is available. Flowers from October to April.
Cultivated for its edible seed since pre-historic times
Detrimental:
Weed of disturbed areas and crops.
Toxicity:
Contains gluco-alkaloids.
Causes fabismus or acute toxic hepatitis when seed is eaten or pollen inhaled by some people. Immature seeds are suspected to be most toxic and the condition may be due to a fungus associated with the bean.
Symptoms:
Anaemia and jaundice.
Acute toxic hepatitis.
Treatment:
Remove stock from area. Watch for signs of yellowing of the skin and whites of the eyes if exposed to pollen or working with Faba Beans. Consult a doctor.
Legislation:
None.
Management and Control:
Grazing and cultivation provide high levels of control.
Thresholds:
1 plant/m2 can cause grain contamination.
Eradication strategies:
Prevent seed set for 5 years by grazing, mowing, pulling or applying herbicides.
Hand spray with 1 g of chlorsulfuron(700g/kg) plus 25 mL wetting agent in 10 L of water or boom spray with 20 g/ha chlorsulfuron(700g/kg) in autumn to early winter each year. Hand pull survivors in spring before seed set.
For small infestations and in 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. For hand spraying use 25 mL wetting agent plus 4 g Lontrel®750 or 1 g Logran® in 10 L water. Repeat annually for several years.
Plant tall growing perennial species to reduce re-invasion.
Metsulfuron also provides good control but is less residual and less selective. It is relatively tolerant to glyphosate.
Herbicide resistance:
None reported.
Biological Control:
Susceptible to Botrytis and Ascochyta. Some varieties are tolerant.
Related plants:
Common Vetch (Vicia sativa ssp. sativa) has leaves are divided like a feather into 3-10 pairs of small narrow leaflets, each 8-30 mm long. It has pink to purple pea flowers, each 10-20 mm long and either single or in few-flowered clusters. The seed pod is narrow, slightly flattened and 30-50 mm long.
Hairy Vetch (Vicia hirsuta) has an elongated inflorescence of several small flowers each only 2-3 mm long and small, 6-9 mm long hairy seed pods.