9. Kickxia Dumort. (canker root)

Plants annuals (perennial herbs or subshrubs elsewhere), with taproots, terrestrial. Stems prostrate, or loosely spreading, sometimes twining and thus climbing on surrounding vegetation, densely pubescent with relatively long, multicellular, gland-tipped hairs. Leaves alternate or the lowermost few opposite, noticeably short-petiolate, not or only slightly expanded at the base. Leaf blades nearly circular to broadly ovate, broadly triangular-ovate, more or less heart-shaped, or halberd-shaped, rounded or less commonly angled to a bluntly pointed tip, rounded to truncate or cordate at the base, unlobed or with a small pair of slender, spreading basal lobes, the margins otherwise entire or with relatively coarse, blunt teeth, pinnately veined or sometimes the smaller leaves appearing more or less palmately 3- or 5-veined from at or near the base, the surfaces and margins densely pubescent with fine, spreading, multicellular hairs, some of the hairs sometimes gland-tipped. Inflorescences axillary, of solitary flowers, the flower stalks 5–14 mm long at flowering becoming elongated to 8–25(–35) mm at fruiting; bractlets absent. Flowers perfect. Calyces deeply 5-lobed nearly to the base, the lobes slightly unequal in length, lanceolate to ovate, sharply pointed at the tip, moderately to densely pubescent with fine, spreading, multicellular hairs, the hairs usually nonglandular. Corollas 6.5–11.0 mm long (including the spur), bilabiate, 5-lobed, spreading-hairy on the outer surface, especially on the tube, the tube somewhat shorter than the lobes, light yellow, the upper lip purple or bluish-tinged, the tube with a well-developed, slender spur 3.5–5.5 mm long at the base (this positioned between the lower 2 calyx lobes), the throat closed by the noticeably convex base of the lower lip, the upper lip usually arched or bent upward, the lower lip with the lobes more or less spreading. Fertile stamens 4, the filaments of 2 lengths, not exserted, the anther sacs spreading, hairy along the margins; staminodes absent. Style 1, not exserted, the stigma capitate, unlobed. Fruits capsules, 3.0–4.5 mm long, globose or nearly so, minutely glandular-hairy on the outer surface, sometimes only toward the tip, the 2 locules equal in size, dehiscent circumscissilely above the midpoint (the upper half of each valve shed). Seeds numerous, 0.8–1.2 mm long, oblong to oblong-ovate, oblong-elliptic, or more or less rectangular in profile, not flattened, the surface dark brown, with a network of convoluted ridges (with tubercles elsewhere), these sometimes appearing winglike. Nine species, Europe, Asia, Africa.

Sutton (1988) and other earlier botanists treated Kickxia in a broad sense to include about 46 species in two well-marked sections. Ghebrehiwet (2001) used molecular markers, cytological, data, and an analysis of morphological features to show that these two sections were sufficiently distinct to represent two sister genera. He chose to segregate the majority of the species into the genus Nanorrhinum Betsche, which is distributed in Africa, Asia, and various oceanic islands. Within Kickxia, Sutton (1988) also chose to recognize various poorly differentiated subspecies within the more widely distributed taxa, but Ghebrehiwet (2001) chose not to treat these.