Herbs, annual [perennial]. Stems decumbent or prostrate to erect [climbing], villous to glandular-hairy [glabrous]. Leaves cauline, alternate, sometimes opposite proximally; petiole present; blade oblong-ovate to orbiculate or cordate, not fleshy, not leathery, margins entire or dentate [lobed]. Inflorescences axillary, flowers solitary; bracts absent. Pedicels present, spreading; bracteoles absent. Flowers bisexual; sepals 5, basally connate, equal, calyx radially symmetric, campanulate, lobes lanceolate [linear], villous; corolla yellow [white], often tinged blue to violet [red], bilaterally symmetric, bilabiate and personate, tubular, tube base not gibbous, spurred abaxially, lobes 5, abaxial 3, spreading, adaxial 2, erect, subequal, apex round; stamens 4, basally adnate to corolla, didynamous, included, filaments incurved, sparsely hairy or glabrous, anthers coherent, ciliate, pollen sacs oblong; staminode 0; ovary 2-locular, villous, locules subequal, placentation axile; stigma capitate. Fruits capsules, dehiscence poricidal [indehiscent]. Seeds [6–]20–40[–60], dark brown to black, oblong-ovoid [reniform], wings absent. x = 9.

Distribution

Eurasia, n Africa, Atlantic Islands, introduced also in Mexico, West Indies, Central America, South America, Pacific Islands, Australia.

Discussion

Species 9 or 46 (2 in the flora).

Kickxia is characterized by personate, long-spurred corollas, coherent anthers, and poricidal capsule dehiscence. Early treatments proposed that Kickxia was congeneric with, or closely related to, Linaria (G. Bentham 1876; P. A. Munz 1926); later taxonomic treatments and phylogenetic analyses have supported generic rank for Kickxia (W. Rothmaler 1943; D. A. Sutton 1988; M. Ghebrehiwet 2001). Morphology- and molecular-based phylogenies support Anarrhinum Desfontaines (x = 10) as the most likely sister group to Kickxia (x = 9) and their basal position in Antirrhineae as the Anarrhinum clade (Ghebrehiwet et al. 2000; P. Vargas et al. 2004).

Although usually considered in a broad sense (D. A. Sutton 1988), N. Yousefi et al. (2016) proposed, on the basis of ITS and trnl sequence data, that Kickxia sect. Valvatae (Wettstein) Janchen be recognized at the genus level. Kickxia then becomes a genus of nine species, with 37 being transferred to Nanorrhinum Betsche.

Selected References

None.

Lower Taxa

Kickxia elatine, Kickxia spuria

Key

1	Leaf blade bases: proximal truncate or rounded to cuneate, distal hastate to sagittate; sepal lobes not accrescent.	Kickxia elatine
1	Leaf blade bases rounded to cordate; sepal lobes accrescent.	Kickxia spuria