False Caper

Euphorbia terracina L.

Family: Euphorbiaceae.

Names:

Euphorbia celebrates Euphorbus, the Greek physician who discovered its medicinal uses.
Terracina refers to an Italian town where it grows in the sand hills.
False caper - refers to its resemblance to the true caper (Capparis spinosa).

Other names:

Carnation weed.
Geraldton Carnation weed - refers to its abundance around the Geraldton area in WA and the similarity of the leaves to those of the Carnation.
Terracina Spurge

Summary:

An erect, pale green, ascending, hairless perennial to 1 metre tall. It has several leafy stems arising from near ground level. The leaves are 15-65 mm long x 2-10 mm wide and have fine teeth near the tip. The flower head is yellow green in summer. In older plants there may be old fruiting and flowering stems mixed with the new season stems. The leaves and stems exude a white, toxic, irritating sap when injured.

Description:

Cotyledons:

Two. Oval, long and thin, more than 10 mm long. Tip round pointed. Edges smooth. Base tapered. Hairless. Merging base. No stalk. Seedling stem has a red base.

First leaves:

Paired. Long and narrow, spear shaped. Tip pointed. Edges smooth and slightly undulating. Base tapered. Hairless

Leaves:

Alternate. Not crowded, Hairless.
Stipules - None.
Petiole - None.
Blade - Pale to bright green, parallel sided to narrowly oblong. 15-65 mm long x 2-10 mm wide. Blunt tip. Edges with very small teeth near the tip. Surface hairless.
Stem leaves - Finely pointed tip.

Stems:

Green to reddish, slender, erect, rigid, round, leafy, 200-1000 mm tall, woody near the base. Usually several arising from the crown. Unbranched near the bottom then divide into 4 or 5 flower stems above a ring of egg shaped floral bracts.
Produces a corrosive, sticky, bitter, milky latex when broken.
Flower stem - Branched at the end of the main stem. Round, fleshy, 50-300 mm long, 2-3 mm diameter, spreading.

Flower head:

Floral leaves egg-shaped and clasp stem. Bracts clasp stem, broadly egg-shaped to triangular with wavy edges, pointed tip and rounded teeth near tip. An umbel of up to 6 branches and these divided into 2 forks many times. Each fork has 2 egg shaped, sessile, floral leaves underneath. Each head has a cluster of 8-15 male and one female flower in a green, cup shaped structure between a pair of floral leaves in the forks of the umbel or at the ends of branchlets.
4 glands, greenish, oval or crescent shaped across the axis with 2-3, long, horn-like appendages.

Flowers:

Unisexual. Involucre is 1-2 mm long, hairless, but with lobes with tiny hairs. Has male and female flowers on the same plant.
Ovary - 3 exerted styles, free almost to the base. Notched or divided at the top.
Calyx - 5 fused bracts look like the calyx with 5 membranous lobes alternating with 4 or 5 broad glands.
Sepals - None.
Petals - None.
Stamens - One.
Anthers -

Fruit:

Smooth, green, pendulous, 3 lobed capsule, depressed, triangular pyramid shaped, 2-5 mm long x 4-5 mm wide, hairless, grooved. Borne on a short stalk. Opens to release seed when ripe. Tip indented. Edges convex. Base indented with stalk remnant.

Seeds:

Light brown to greyish or black, may be finely mottled, shiny, smooth, globular, 1-2 mm. Hairless. Has a white fleshy "hat" on the end. Tip somewhat pointed, Base rounded or pointed. Edges rounded.

Roots:

Strong taproot with horizontal laterals at various depths.

Key Characters:

Alternate stem leaves oblong without stipules or petioles. Bracts with small teeth. Glands of involucre have 2 pointed horn like appendages. Brown, globular seeds.

Biology:

Life cycle:

Perennial. Seeds germinate from autumn to spring and produce several stems from the crown. 4-5 flowering stems form at the end of these in late winter. These divide into 2 a number of times to form pendulous flowering branchlets. Flowering starts in spring (August) and continues until summer (October) drought stops it. New stems are formed from the crown in the next season. There may be a mixture of new season stems and old season flowering stem on the plant simultaneously.

Physiology:

Reproduction:

By seed.

Flowering times:

Winter to spring in western NSW.
July to October in SA.
August to October in Perth.
Summer in WA.

Seed Biology and Germination:

Vegetative Propagules:

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed especially in moving water along streams and by mud attached to animals, machinery and vehicles.
Seed is explosively ejected several metres from the capsule.

Origin and History:

Mediterranean.
It was common in WA by 1914.
Declared in SA in 1903.

Distribution:

NSW, QLD, SA, VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

In warm temperate areas, with winter dominant rainfall.

Soil:

Sandy soils, especially near the coast where limestone is present.
On a red earth in NSW.

Plant Associations:

Tuart woodlands. Coastal heath.

Significance:

Beneficial:

Detrimental:

Weed of pasture, vegetables, roadsides, gardens, coastal heath, tuart woodlands and disturbed areas.
Unpalatable.

Toxicity:

Toxic due to hydrocyanic acid but rarely causes problems unless stock have no other feed.

Legislation:

Noxious weed of SA and WA.

Management and Control:

Cultivation will control it but erosion risk is high on most soils where it flourishes. Planting competitive species such as perennial veldt grass or lucerne has provided good control. Seed is transported in water and mud.
It does not persist under frequent cultivation associated with conventional cropping.
Some control achieved with hormone herbicides, amitrole, atrazine, triclopyr and sulfonylurea herbicides.

Thresholds:

Eradication strategies:

Manually remove isolated plants and burn them.

Herbicide resistance:

Biological Control:

Related plants:

Asthma plant (E. hirta)
Bottle tree Caustic (E. stevenii)
Caper Spurge (E. lathyrus)
Caustic weed (E. drummondii)
Climbing Caustic (E. sarcostemmoides)
Cypress Spurge (E. cyparissias)
Desert Spurge (E. tannensis ssp. eremophila)
Dwarf Poinsettia (E. cyathophora)
Dwarf Spurge (E. exigua)
Eyebane (E. maculata)
Garden weed (E. segetalis)
Gascoyne Spurge (E. boophthona)
Hairy Caustic Weed (E. australis)
Mexican Fire plant (E. heterophylla)
Naked Lady (E. tirucalli)
Petty Spurge (E. peplus)
Plains Spurge (E. planiticola)
Poinsettia (E. pulcherrima)
Red Caustic creeper (E. prostrata)
Red Caustic Creeper (E. thymifolia)
Sea Spurge (E. paralias)
Sickle leaved Spurge (E. falcata)
Snow on the Mountain (E. marginata)
Sun Spurge (E. helioscopia)
Tree Spurge (E. dendroides)
E. dentata
E. hyssopifolia

Plants of similar appearance:

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P509, 517. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P458-459. 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). P146. 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). #.535.28.

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). P450.

Meadly, G.R.W. (1965). Weeds of Western Australia. (Department of Agriculture - Western Australia). P107-109. Diagrams. Photos.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P80. Diagrams. Photos.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P424-426. Photos.

Acknowledgments:

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