pronounced: bar-LEER-ee-uh kriss-TAH-tuh
The genus name Barleria is in honour of Jacques Barrelier (1606-1673), a French Dominican monk who was a physician, botanist, plant collector and author; cristata is from the Latin cristatus, crested.
This is a native of southern Asia, where it grows in southern China, Nepal, Burma, Indo-China, the Philippines, Bangladesh, India, Sri Lanka and Pakistan. It is found naturalized on Christmas Island, in Florida, and on several Pacific Islands, especially Fiji, New Caledonia and Hawaii, and occasionally in northern and south-eastern Queensland. Commonly cultivated as a garden plant, it has the potential to become an environmental weed, especially in riparian areas.
Barleria cristata is an erect, branched shrub that grows 1 to 2 m high. The branches are sparingly hairy. The leaves have a hairy petiole; they are oblong-elliptic to lanceolate, 3 - 12 cm by 1 - 3.5 cm, hairy on both surfaces, attenuate at the base, entire, with acute-attenuate tips.
The flowers are purple-blue, about 5 cm long, in short 1 - 5 flowered axillary or terminal spikes; the bracts are absent or lanceolate, about 1 cm long, bristly on the margins, scabrous, acute; bracteoles are absent. The calyx is deeply 4-cleft, the outer pair of lobes larger than the inner pair, ovate-lanceolate, acuminate, bristly toothed on the margins, hairy or glabrescent. The corolla tube is about 4 cm long, infundibuliform.
The capsule is ellipsoid, 1.5 - 2 cm long, glabrous, pointed at the base and apex, 4-seeded. The seeds are orbicular, about 4 mm across, appressed hairy. The plant spreads readily by seed, and can easily become a nuisance in the garden if not kept under control.
A white-flowered cultivar (‘Alba’) is present amongst both cultivated and naturalized populations. There is also a variegated-leaf form that has spectacular foliage but few blooms.
Extracts of the roots, leaves and seeds have been used in traditional medicines. The seeds are used as an antidote for snakebite; the roots and leaves to reduce swelling, and to treat coughs; parts of the plant are also used to treat toothache, anaemia and inflammatory disorders.