Pea

Pisum sativum L. s. lat.

Synonyms - Pisum arvense L.

Family: Fabaceae

Names:

Field pea.

Other Names:

Canning Pea
Field Pea
Garden Pea
Green Pea
Processing Pea
Semi-leafless Field Pea
Snow Pea
Sugar Snap Pea
Trailing Field Pea

Summary:

A leguminous, annual vine crop with pea type flowers and pods with large globular seeds.

Description:

Cotyledons:

Two, large. Do not emerge. Round tips. Edges smooth and round. Base round. Hairless. On a short stalk.

First leaves:

Trailing Field Pea:
First leaf has a short terminal tendril between 2 heart shaped leaflets with no point. Edges of leaflets are slightly toothed. Stipules are large and oval with a pointed tip and toothed edges.
Second leaf has a short terminal tendril between 2 oval leaflets with indented tips with a small point. Edges of leaflets are slightly toothed. Stipules are large and oval with a pointed tip and toothed edges.
Semi-leafless Field Pea:
First leaves are tendrils with 4-6 branches. Stipules are leaf like with undulating edges, a spear shaped central lobe and 2 triangular side lobes. There are small teeth on the basal lobe.

Leaves:

Alternate. Does not form a rosette.
Trailing Field Pea:
1-3 pairs of oval leaflets and a terminal tendril.
Stipules - Leaf like stipules at the base of the leaf stalk. Hairless. Often have grey mottle.
Petiole - yes.
Blade - Of leaflets oval. Tip pointed. Edges smooth, Base tapered
Semi-leafless Field Pea:
Leaves replaced by tendrils.

Stems:

Trailing Field Pea:
Branched, twining, sprawling. Up to 2000 mm long. Hairless.
Semi-leafless Field Pea:
Weakly erect and held upright by intertwining tendrils. Sprawling. Up to 1000 mm long.

Flower head:

Single stalked flowers in the leaf axils.

Flowers:

White, blue or purple pea type.
Ovary - Superior, 1 celled, Simple style.
Calyx - 5 lobed.
Petals - White with green veins or blue or purple with a lighter standard with dark veins.
Stamens - 10.
Anthers -

Fruit:

Pod with 3-8 seeds in an apparently single row attached to the bottom side. Opens along the top seam in two valves.

Seeds:

Brown, green or white, round, 4-8 mm diameter, Often with a few large dimples. Tip round. Edges smooth, convex or concave. Base round to slightly indented. Surface smooth and hairless. Often break into two halves. Flesh is yellow or green. Embryo curved.

Roots:

Taproot with nitrogen fixing nodules.

Key Characters:

Branched tendrils.
White, blue or purple pea type flowers.
Pod with 3-8 large round seeds that are 4-8 mm diameter.

Biology:

Life cycle:

Annual. Germinates autumn/winter. Flowers late-winter/spring

Reproduction:

Flowering times:

Spring.

Seed Biology and Germination:

Little hard seed.

Vegetative Propagules:

None

Population Dynamics and Dispersal:

Spread by seed.

Origin and History:

Europe and Mediterranean.

Distribution:

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

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate.

Soil:

Prefers well drained soils.

Significance:

Beneficial:

Cultivated crop.
Food and fodder.
Fixes nitrogen.

Detrimental:

Weed of other crops.
Causes soil acidification. Add 10-60 kg/ha lime per tonne of Peas produced to ameliorate acidification.

Toxicity:

Sheep grazing stubble may get grain poisoning especially after rains.
Young pea vines may cause bloat.

Symptoms:

Bloat or grain poisoning.

Treatment:

Remove stock.

Legislation:

None.

Management and Control:

Thresholds:

10-20 plants/m2 can cause significant yield reductions. Lower levels can lead to grain contamination.

Eradication strategies:

Prevent seed set for 3 years.

Herbicide resistance:

None reported.

Biological Control:

Susceptible to black spot.

Related plants:

No other plants in this genus are in Australia.

Plants of similar appearance:

Vetches, Lathyrus.

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P399.

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). #985.2.

McBarron, E.J. (1983). Poisonous plants. (Inkata Press, Melbourne). P139.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P92-93. Diagrams. Photos.

Acknowledgments:

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