Tridax procumbens

tridax daisy


Tridax procumbens

L. 1753

pronounced: TRY-daks pro-KUM-benz

(Asteraceae — the daisy family)


common names: tridax daisy, Jack-Jack-pop-off-your-head

Tridax is derived from the Greek τριδακτυλος (tridaktylos), three-fingered or -toed, referring to the three-toothed ray florets. Procumbens is Latin for ‘falling forwards, lying down’.

This native to Central America and tropical South America is now found naturalized throughout the whole of the tropical and subtropical world, and even in many semi-temperate regions. It is a weed of fallow land, fields, waste areas, roadsides, and lawns.

The plant is a semi-prostrate perennial herb with a slender tap root. The leaves are simple, opposite, toothed and generally sagittate, hairy on both surfaces, bright green above and grey-green below. The stems are more or less ascending, up to 50 cm high, round in cross-section, striate, and sparsely to very hairy.

The plant bears daisy-like yellow flowers, 1–2 cm across, solitary with 5 or 6 three-toothed ray florets. These ray florets are yellow or white, and the inner disk florets dark yellow and hairy.

Its fruit is a hard achene covered with stiff hairs and having a feathery, plume-like white pappus at one end. The persistent pappus, about 6 mm long, consisting of about 20 straw-coloured scale-like bristles, enables the achenes to be carried by the wind over a wide range. The achenes are a couple of mm long, tapering to the base, covered with long hairs. The large number of achenes produced per plant (anything up to 1,500) accounts for the plant’s widespread distribution. The plants often root at the nodes.

As very small children, my playmates and I would sit in a circle on the grass, each with a flower of this plant in front of him. Each boy or girl in turn would prepare a flower, still on its stem, between thumb and index finger as if preparing to shoot a taw in a game of marbles, point it at the child sitting opposite, and shout, “Jack, Jack, POP off your head!” At the word ‘POP’, the flower was flicked off in attempt to hit the other child, preferably in the face.


Photographs taken at Picnic Bay 2009
Page last updated 24th April 2019