Tetragonia refers to the 4 angled fruit. Tetra is Greek for four and gonia means angle.
Sea Spinach. Spinach refers to its taste.
Other Names:
Summary
A semi-succulent, soft, prostrate, densely warty perennial, 10-30 cm high and up to 5 metres wide with 15-45 mm long leaves that are covered with glistening water storage cells. It has yellow, 4-lobed flowers in the leaf axils.
Description
Cotyledons:
Two.
Leaves:
Alternate, succulent, thick, pale green, with small glistening watery blisters.
Stipules - None
Petiole - Merges into blade.
Blade - Spear to egg shaped, 15-45 mm long by 7-27 mm wide, thick and fleshy and tapering to the petiole. Tip rounded. Sides convex and curved downward at the edges. Base tapered. Surface glistening. Hairless.
Stems:
Prostrate, running, thick somewhat grooved or ridged and somewhat succulent, up to 2.5 m long. Warty.
Flower head:
Flowers usually in clusters of 2 or 5 in the upper leaf axils.
Flowers:
Yellow, in leaf axils, bisexual or male, on a 3-12 mm long stalk (pedicel) that is hairy or with tiny nipple like warts.
Ovary - Inferior or half inferior. 1 pendulous ovule in each cell.
Style - 3 or 4, 2.3-3.2 mm long.
Perianth - Yellow and tubular with 4 (usually) lobes that are 2.5-4 mm long. Tube of bisexual flowers 2.5-4 mm long and 3 or 4 ribbed. Warty on the outside.
Stamens - 12-25 2.5-3 mm long. Free. Inserted at the top of the perianth tube and sometimes clustered.
Anthers -
Fruit:
Dry, hard, brown and 3 or 4 winged. Flat on top. Usually 10-14 mm long.
Seeds:
Pale brown, pear to kidney shaped.
Roots:
Taproot.
Key Characters:
Flowers yellow
3 or 4 styles
Fruits dry, hard with 3 or 4 prominent wings.
Adapted from Judy Wheeler and Neville Marchant.
Biology
Life cycle:
Perennial.
Physiology:
Reproduction:
Flowering times:
March to November in WA.
Seed Biology and Germination:
Vegetative Propagules:
Hybrids:
Population Dynamics:
Origin and History:
South Africa.
Distribution:
SA, WA.
Great southern, Swan coastal plain and Warren regions in WA.
Habitats:
Climate:
Coastal.
Soil:
Prefers sandy soils and dunes and sand over limestone.
Plant Associations:
Significance:
Beneficial:
Detrimental:
May be toxic.
Weed of coastal dunes and heathlands.
Toxicity:
Possibly toxic as the closely related New Zealand Spinach (Tetragonia tetragonoides) is toxic.
Symptoms:
Treatment
Legislation:
None.
Management and Control:
A number of herbicides in the hormone and picolinic acid group are used for control.
Thresholds:
Eradication strategies:
Tordon® or Grazon® are the likely to provide high levels of control.
Herbicide resistance:
None reported.
Biological Control:
Related plants:
Native Spinach (Tetragonia eremacea)
New Zealand Spinach (Tetragonia tetragonoides) has greenish flowers rather than yellow.
Tetragonia fruticosa
Tetragonia nigrescans
Plants of similar appearance:
Canary Creeper (Senecio tamoides)
Iceplant (Mesembryanthemum crystallinum).
References:
Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).
Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).
Felfoldi, E.M. (1993). Identifying the Weeds Around You. (Department of Agriculture Victoria). P
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). P76. Photo.
Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #985.1
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). P79.
Paczkowska, G. and Chapman, A. (2000). The Western Australia flora: a descriptive catalogue. (Wildflower Society of Western Australia (Inc), the Western Australian Herbarium, CALM and the Botanic Gardens & Parks Authority). P135.
Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn). P. Photo.
Wheeler, Judy, Marchant, Neville and Lewington, Margaret. (2002). Flora of the South West: Bunbury - Augusta - Denmark. (Western Australian Herbarium, Bentley, Western Australia). P473. Diagram.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.