Commelina cyanea

scurvy weed


Commelina cyanea

R.Br. 1810

pronounced: kom-uh-LEE-nuh ky-AN-ee-uh

(Commelinaceae — the wandering Jew family)


common names: scurvy weed, native wandering Jew

native 4Commelina, and the Commelinaceae family, was named for two 17th century Dutch botanists: Johan Commelin and his nephew Caspar Commelin. They were both known to Linnaeus. Johan, also known as Jan Commelijn, became Professor of Botany at Amsterdam, and was instrumental in making the Amsterdam Botanical Garden one of the finest of its time. This was a time when hundreds of plants new to Europe were being imported from the Cape and Ceylon, and when Linnaeus was developing his system of plant classification. Commelin took a leading part in the preparation for publication of several important botanical works, but is chiefly remembered for the book Horti Medici Amstelodamensis Rariorum, a very comprehensive description, with illustrations, of all the rare and exotic herbs found in the Amsterdam Botanical Garden. He died before the book could be published, and the work was completed and published by his nephew Caspar five years after his death.

Cyanea is from the Greek κυανος (kyanos), dark blue.

This plant is found in the forests and woodlands of the coastal regions of Queensland (including the whole of Cape York Peninsula), NSW, and the Northern Territory east of Arnhem Land. It is also found on Lord Howe Island and Norfolk Island. It was one of the many species described by Robert Brown in his 1810 work Prodromus Floræ Novæ Hollandiæ et Insulæ Van Diemen. The plant has been observed on Magnetic Island, but I have not managed to sight it here personally.

It is a trailing herbaceous perennial plant whose stems grow along the ground. The nodes root readily where they come in contact with the soil. The plants die off in winter. The leaves are ovate to narrow-ovate, 2 – 7 cm by 0.5 – 1.5 cm. The flowers can occur at any time from spring to autumn. They are a deep cobalt blue in colour, about 1.5 cm in diameter, with 3 blue petals, and are followed by a capsule bearing 2 – 5 seeds, each 2 – 3 mm long.

Pollination is performed by a variety of native bees such as Nomia aurantifer and Amegilla pulchra, by halictid and colletid bees, and by syrphid flies of the genus Syritta. Wallabies and rabbits eat the vegetation, as also do the caterpillars of the moth Rhynchina obliquarlis.

The leaves are used as a vegetable. Early settlers used the leaves to alleviate scurvy; hence the common name.

This is an attractive plant when in flower, and can be grown as ground cover or in hanging baskets. It is easily propagated from cuttings.


Vegetation of Magnetic Island, C. Sandercoe 1990


Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.


Photograph taken at Morayfield 2013
Page last updated 17th November 2018