Commelina cyanea, commonly known as scurvy weed, is a perennial prostrate herb of the family Commelinaceae

Commelinaceae

Commelinaceae is a family of flowering plants. In less formal contexts, the group is referred to as the dayflower family or spiderwort family. It is one of five families in the order Commelinales and by far the largest of these with an estimated 650 species in 40 genera. Well known genera include...

 native to moist forests and woodland

Woodland

Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...

s of eastern Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, Lord Howe Island

Lord Howe Island

Lord Howe Island is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, directly east of mainland Port Macquarie, and about from Norfolk Island. The island is about 11 km long and between 2.8 km and 0.6 km wide with an area of...

 and Norfolk Island

Norfolk Island

Norfolk Island is a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia. The island is part of the Commonwealth of Australia, but it enjoys a large degree of self-governance...

. The blue flowers appear over the warmer months and are pollinated by bees and flies.

Taxonomy

Commelina cyanea was one of the many species initially described by the botanist Robert Brown

Robert Brown (botanist)

Robert Brown was a Scottish botanist and palaeobotanist who made important contributions to botany largely through his pioneering use of the microscope...

 in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen

Prodromus Florae Novae Hollandiae et Insulae Van Diemen

Prodromus Florae Novae Hollandiae et Insulae Van Diemen is an 1810 flora of Australia by botanist Robert Brown. Often referred to as Prodromus Flora Novae Hollandiae, or by its standard botanical abbreviation Prodr. Fl. Nov. Holland., it was the first attempt at a survey of the Australian flora...

and still bears its original name. The genus name Commelina was chosen based on the Asiatic dayflower. Linnaeus picked the name in honour of the Dutch botanists Jan

Jan Commelin

Jan Commelin , also known as Jan Commelijn or Johannes Commelinus, was the son of Isaac Commelin a historian; his brother Casparus was a bookseller and newspaper publisher. Jan a botanist became a professor of botany when many plants were imported from the Cape and Ceylon and a new system had to be...

 and Caspar Commelijn

Caspar Commelijn

Caspar Commelijn or Caspar Commelin , was a Dutch botanist. He was the son of the bookseller, historian and publisher, Casparus Commelijn and his first wife, Margrieta Heydanus...

, using the two large showy petals of Commelina communis

Commelina communis

Commelina communis, commonly known as the Asiatic dayflower, is an herbaceous annual plant in the dayflower family. It is native throughout much of East Asia and northern parts of Southeast Asia. In China, the plant is known as yazhicao , roughly translating to "duckfoot herb", while in Japan it...

to symbolise them. The specific name is the Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 adjective cyaneus, meaning "blue". As well as scurvy weed, alternative common names include (native) wandering Jew, forget-me-not, and creeping Christian.

Description

Commelina cyanea is a trailing herbaceous perennial plant, whose stems grow along the ground. It readily roots at the nodes when they come into contact with the soil. They die off in winter. The leaves are ovate to narrow-ovate, and measure 2–7 cm (0.8-2.8 in) long by 0.5-1.5 cm (0.2-0.6 in) wide. The flowers can occur at any time from spring to autumn. They are deep blue and about 1.5 cm (0.6 in) in diameter, followed by a capsule bearing 2-5 2-3 mm long seeds.

Distribution and habitat

The range across eastern New South Wales, from Narooma northwards, up into Queensland. It also occurs on Lord Howe Island, and Norfolk Island. It grows in wetter shaded areas in forest habitats.

Ecology

Commelina cyanea is pollinated by a variety of native bees such as Nomia aurantifer, Amegilla pulchra, halictid

Halictidae

Halictidae is a cosmopolitan family of the order Hymenoptera consisting of small to midsize bees which are usually dark-colored and often metallic in appearance...

 and colletid

Colletidae

Colletidae is a family of bees, and are often referred to collectively as plasterer bees or polyester bees, due to the method of smoothing the walls of their nest cells with secretions applied with their mouthparts; these secretions dry into a cellophane-like lining...

 bees, and syrphid flies (genus Syritta

Syritta

Syritta is a genus of hover flies.The genus probably originated in the Afrotropical region. 13 of the 18 recognized species groups are found south of the Sahara. 15 species inhabit the Oriental and Australian-Pacific regions, and only six species are described from the Palearctic region. The two...

). Wallabies and rabbits eat the vegetation. Vegetation is also possibly dispersed by water.

Uses

The leaves are used as an edible vegetable. The leaves were used by early non-indigenous colonists to alleviate scurvy

Scurvy

Scurvy is a disease resulting from a deficiency of vitamin C, which is required for the synthesis of collagen in humans. The chemical name for vitamin C, ascorbic acid, is derived from the Latin name of scurvy, scorbutus, which also provides the adjective scorbutic...

, and hence its common name.

Attractive in flower, Commelina cyanea adapts readily to cultivation and can be grown as a groundcover or in hanging baskets. It is easily propagated from cuttings. It does resemble the introduced weed wandering jew (Tradescantia fluminensis

Tradescantia fluminensis

Tradescantia fluminensis is a species of spiderwort native to South America. It is one of several plants known by the common name Wandering Jew. It is also known as River Spiderwort, Small-Leaf Spiderwort, Inch Plant, Wandering Trad and Wandering Willie.T...

), but the latter has white flowers and a segmented stem, a weak root system. It also lacks the hairy leaf sheathes of C. cyanea. However, C. cyanea can itself be weedy in gardens at times.