pronounced: kam-ay-SY-kee mak-gill-iv-RAY-ee
pronounced: yoo-FOR-bee-uh mak-gill-iv-RAY-ee
I am using the name Chamaesyce macgillivrayi for this species with some misgivings. All of the Australian sources consulted give it as the accepted name, with Euphorbia macgillivrayi as the synonym; but GRIN, the main US authority, states that Chamaesyce is “a probable synonym of Euphorbia”, and the Kew Gardens Plant list, which purports to sort out all the botanical names once and for all, emphatically gives Euphorbia macgillivrayi as the accepted name, with Chamaesyce macgillivrayi as the synonym. My inclination generally is to follow Kew, but this time I yield to the Australian usage.
Chamaesyce is derived from the Greek χαμαι (chamai), on the ground, and συκον (sykon), a fig; macgillivrayi is for John MacGillivray (1821-1867), botanist and natural history collector for the Earl of Derby on board the Fly on its marine survey of Australia in 1842-45, and also the naturalist on the Rattlesnake in 1847-50 and on the Herald in 1853-54.
This is a fairly uncommon perennial weed of waste places, growing in sandy soils along the Queensland coast and the northern coastal strip of NSW. It is either erect or decumbent, depending on the soil type and the surrounding vegetation, growing to 30 cm high, but more usually under 20 cm. The plant is more-or-less pubescent. Depending on where it is growing, the stems often have a reddish tinge.
The leaves are oblong-ovate, mostly between 1 and 4.5 cm in length by less than 1 cm in width, with toothed margins; the base asymmetric or more-or-less cordate; both surfaces start our with long scattered hairs, but become more-or-less glabrous, particularly on the upper surface, as they age. The petiole is very short, only about 2 mm, and the stipules are deeply lobed or fringed.
The cyathia (characteristic inflorescence of the family) are in dense, shortly pedunculate cymes, with the floral leaves either reduced, or with only the lower pair leafy; the involucre is less than 2 mm in length. The main flowering period is in the summer.
A capsule is produced, also less than 2 mm in length, and glabrous, containing greyish brown or grey seeds a little over 1 mm long, that are transversely wrinkled.
Joseph Banks and his party saw this species at Thirsty Sound, NSW, in May, 1770.
