Tragopogon porrifolius L.

Synonyms -

Family: - Asteraceae


Tragopogon from the Greek tragos, a goat and pogon, a beard and refers to the pappus of the seed which looks like a goats beard.

Porrifolius means leaves like a leek.

Other Names:

Jerusalem Star

Oyster Plant because the edible taproot has an oyster flavour.



An erect, stout, purple daisy flowered, hairless biennial to 1.3 m high with long grass like leaves and a fleshy taproot. It grows in damp places and exudes a milky sap when damaged.




First leaves:


Alternate stem clasping grass like leaves. Exude white sap when damaged.

Stipules - None.

Petiole - None.

Blade - Long, broad, half clasping, smooth edged, up to 600 mm long by 5-20 mm wide, somewhat fleshy, parallel veined. Tip pointed, Edges smooth. Base clasping. Hairless.

Stem leaves - Shorter with broader, stem encircling bases.


Erect, up to 1000 mm tall. Sparingly branched. Hairless.

Flower stem - Hollow near the top, leafless, striped, swollen below the head. Hairless. Exude white sap when damaged.

Flower head:

Single flower on the end of a long stem or branches. 30-50 mm long. About 8 lance shaped papery bracts in one row and overlapping at the base, hairy on the inner face, hairless on the outer face. Bracts are usually longer than the purple petals, 25-40 mm long when in flower, and 40-70 mm long when in fruit.


Purple with darker centres, open in the morning and close during the day.

Receptacle - naked, pitted.

Ovary -

Style - long branches

Petals - Lilac, deep violet or reddish purple, 20 mm long, 5 small teeth at the tip.

Stamens - Many

Anthers - Yellow. Arrow shaped at the base.


Achene with beak and pappus. The fruits form a large, round, pale brown, silky ball at maturity and are dislodged by gusts of wind.


Oval to somewhat cylindrical, slightly curved, 14 mm long, tapering to a long slender beak up to 21 mm long. Pappus feathery with about 25 golden brown, barbed bristles, 20 mm long with soft inter woven barbs. Outer ones with 10, toothed ribs, inner ones smoother


Long, thick, cylindrical, fleshy, tuberous taproot.

Key Characters:

Plants with milky sap and hairless at maturity sometimes floccose when young..

Leaves linear, entire, broadly sheathing at the base, radical and cauline

Stems leafy, peduncles leafless.

Involucre bracts few (about 8) and in one row.

Florets without chaffy scales between them. (Receptacle naked)

Flowers purple or pinkish, all ligulate, all bisexual.

Outer ligules radiating.

Style with plano convex branches, attenuated toward the summit, bearing stigmatic papillae on the whole of the inner side and well developed collecting hairs on the outside down to below the place where the branches fork.

Anthers acute or acuminate at the base.

Achenes fusiform, beaked.

Beak not swollen at base.

Pappus of plumose bristles. Plumose branches of the pappus intertwining.

Adapted form John Black, Nancy Burbidge and N Lander.


Life cycle:

Annual or biennial herb



By seed.

Flowering times:

October to December in SA.

Spring in Western NSW

November in WA.

September to March in New Zealand.

Seed Biology and Germination:

Vegetative Propagules:



Population Dynamics and Dispersal:

Spread by wind assisted seed dispersal. Usually in small but often dense colonies. Its main growth is in the cooler months and the tops or whole plant dies off over summer.

Origin and History:

Mediterranean, Europe, North Africa.







Prefers moist soils.

Plant Associations:



Cultivated for it fleshy, oyster flavoured taproot which is eaten as a vegetable and prepared similarly to parsnip. The young leaves are also steamed as a vegetable.



Weed of drains, waterways, roadsides, settlements, grass lands and moist disturbed areas


Not recorded a s toxic.





Management and Control:

Avoid dumping garden and household refuse in damp places. Normal grazing and cultivation appears to keep it under control in agricultural situations. Dense colonies can be grazed with pigs.


Eradication strategies:

Spray colonies until just wet with 200 mL Lontrel in 100 L water in winter or spring before flowering for reasonably selective control in bushland situations. Repeat annually for 2-3 years. In open areas 1 L Tordon 75-D per 100 L water applied in winter should provide control of existing plants and leave a soil residual to control seedlings. Repeat annually as required.

Sow dense understorey species to increase the level of shade to reduce re infestation.

Herbicide resistance:

None reported

Biological Control:

Related plants:

Tragopogon dubius

Tragopogon hybridus

Plants of similar appearance:


Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P119. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P939. Diagram.

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P402. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P714. Photo.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume . P. Diagram.

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). P106. Photo.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). 1005.3.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P709.

Roy, B., Popay, I., Champion, P., James, T. and Rahman, A. (1998). An Illustrated Guide to Common Weeds of New Zealand. (New Zealand Plant Protection Society). P89. Photo

Stucky, J.M. (1981). Identifying Seedling and Mature Weeds Common in the Southeastern United States. (The North Carolina Agricultural Research Service and The North Carolina Agricultural Extension Service, North Carolina State University, Raleigh).


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