Kickxia is a genus of annual and perennial flowering plants in the plantain family (Plantaginaceae), order Lamiales. Commonly known as cancerworts or fluellins, the roughly 45 species in the genus are characterised by small snapdragon-like flowers with spurred corollas and typically hastate or sagittate leaves. The genus belongs to tribe Antirrhineae and is closely allied to Linaria and Cymbalaria.
The genus is largely centred on Europe, the Mediterranean basin, Central Asia, and Africa, with its greatest diversity in the Old World. Two species, Kickxia elatine (sharp-leaved fluellen) and Kickxia spuria (round-leaved fluellen), have become widely naturalised outside their native range and are considered agricultural weeds in parts of North America, Australia, and beyond, often colonising arable fields and disturbed ground.
Kickxia was named in honour of Jean Kickx, a nineteenth-century Belgian botanist and pharmacist. The genus was previously placed in Scrophulariaceae under older classifications but is now firmly assigned to Plantaginaceae following molecular phylogenetic revision. Several species formerly treated within Kickxia have been transferred to the segregate genus Nanorrhinum.
Etymology
The genus name Kickxia honours Jean Kickx (1775–1831), a Belgian botanist and pharmacist who contributed to the study of Belgian flora and mycology. The common names "fluellen" and "cancerwort" are historical English names for the two species most familiar in Europe, K. elatine and K. spuria.
Distribution
Kickxia species are native primarily to Europe, the Mediterranean region, Central Asia, and Africa. Kickxia elatine and Kickxia spuria are the most widespread members and have naturalised as weeds in temperate regions worldwide, including parts of North America and Australia, typically in arable fields and disturbed habitats.
Taxonomy Notes
Kickxia is placed in the family Plantaginaceae (order Lamiales) under current APG classification, within tribe Antirrhineae alongside Linaria, Antirrhinum, and allied genera. Older classifications assigned the genus to Scrophulariaceae. Several species formerly included in Kickxia have been moved to the closely related segregate genus Nanorrhinum.
