Howelliella

Herbs, annual. Stems erect or ascending, filiform, twining branches absent, glandular-pubescent. Leaves cauline, opposite proximally, alternate distally; petiole present proximally, nearly absent distally; blade not fleshy, not leathery, margins entire. Inflorescences terminal, racemes; bracts present. Pedicels present, not twining; bracteoles absent. Flowers bisexual; sepals 5, basally connate, calyx bilaterally symmetric, tubular to cupulate, lobes ovate or lanceolate, adaxial lobe larger; corolla creamy white to pale pink, bilaterally symmetric, strongly bilabiate, tubular, tube base gibbous abaxially, not spurred, lobes 5, abaxial 3, adaxial 2; stamens 4, basally adnate to corolla, didynamous, filaments glandular-hairy distally, pollen sacs 2 per filament; staminode 0; ovary 2-locular, placentation axile; stigma punctiform. Fruits capsules, locules equal to subequal, dehiscence poricidal. Seeds 15–50, brown to black, ovoid to subconical, wings absent. x = 16.

Distribution

Calif.

Discussion

Species 1.

Howelliella is rare and closely related to Sairocarpus, but the palate does not block the mouth of the corolla tube, the floor of the corolla tube has two longitudinal folds, and the abaxial lip is relatively small. The corolla tube is slightly curved in Howelliella; it is straight in related species. Morphological and molecular studies agree that Howelliella is most closely related to S. subcordatus and S. vexillocalyculatus, which also have greatly enlarged adaxial calyx lobes (D. M. Thompson 1988; R. K. Oyama and D. A. Baum 2004; M. Fernández-Mazuecos et al. 2013).

Selected References

None.

Lower Taxa

Howelliella ovata