Lechenaultia is a genus of flowering plants in the family Goodeniaceae (order Asterales), comprising around 30 species all native to Australia, with a single species, L. filiformis, also extending to New Guinea.
Plants in the genus are glabrous (hairless) shrubs or herbs with spreading branches. The leaves are linear or cylindrical — sometimes reduced to scales — and are more or less sessile. Flowers are borne with five sepals that are free from one another, and five glabrous petals arranged in two unequal lobes: the two back petals are shorter with narrow wings near the tip, while the three lower petals are longer with broad wings. Flower colours range from vivid blue and white to yellow and red, making several species popular in horticulture. The fruit is a cylindrical capsule that splits into four valves.
The great majority of species are concentrated in the south-west of Western Australia, where they grow in shrubland on well-drained, sandy soils. A handful of inland species extend into the Northern Territory, South Australia, Queensland, and New South Wales, typically in open grassland or woodland. Lechenaultia biloba, known as blue leschenaultia, is one of the most widely recognised species, prized for its vivid blue flowers.
The genus was formally described by Robert Brown in 1810 in Prodromus Florae Novae Hollandiae et Insulae Van Diemen, named in honour of the French botanist Jean Baptiste Leschenault de la Tour, who accompanied the Baudin expedition to Australia. The type species is Lechenaultia formosa, the red leschenaultia.
Etymology
The genus name Lechenaultia was coined by Robert Brown in 1810 to honour Jean Baptiste Leschenault de la Tour, the botanist attached to the Baudin expedition to Australia. Brown omitted the 's' from Leschenault's name (using the French spelling), though George Bentham later introduced a variant with the 's' (Leschenaultia) that was widely followed before the original Brown spelling was restored in the 1950s.
Distribution
Nearly all Lechenaultia species are endemic to Australia, with the greatest concentration in the south-west of Western Australia, where they grow in shrubland on well-drained, sandy soils. A smaller number of species range into inland areas — Northern Territory, South Australia, Queensland, and New South Wales — in open grassland or woodland. One species, L. filiformis, also occurs in New Guinea. The notable exception to the sandy-soil preference is L. expansa, which grows in permanently wet soil.
Ecology
Charles Darwin investigated the fertilisation mechanism in Lechenaultia and proposed that the upper anther "has been converted into a short broad strap," physically preventing the stigma from contacting pollen from the same flower's fertile anthers — an adaptation promoting cross-pollination and reducing self-fertilisation.
Cultivation
Several Lechenaultia species, especially L. biloba (blue leschenaultia) and L. formosa (red leschenaultia), are cultivated as ornamentals for their vivid flowers. In cultivation they require excellent drainage and prefer sandy, low-nutrient soils that mimic their native south-west Australian habitat; waterlogging is typically fatal. They are commonly grown in rockeries, containers, or raised beds in Mediterranean-climate gardens.
