Chylismia confertiflora

Herbs annual, densely villous and strigillose, glandular puberulent on distal parts. Stems well branched, 15–50 cm. Leaves in well-developed basal rosette and also cauline, 7–20 × 1.5–2.5 cm; petiole 1–4(–8) cm; blade pinnately lobed, terminal lobe oblanceolate to narrowly ovate, 2.5–5 × 1–2.5 cm, margins irregularly dentate, oil cells on abaxial surface inconspicuous. Racemes nodding, dense, mostly elongating after flowers open. Flowers opening at sunrise; buds with conspicuous, subapical free tips 1–2 mm; floral tube 3–5 mm, short-villous inside proximally; sepals 9–12 mm; petals bright yellow, with red dots at base, fading lavender, 12–18 mm; stamens unequal, filaments of antisepalous stamens 6–8 mm, those of antipetalous ones 4–5 mm, anthers 4–6 mm, ciliate; style 11–18 mm, stigma exserted beyond anthers at anthesis. Capsules ascending or spreading, oblong-cylindrical, immature capsule to 35 mm; pedicel 5–15 mm. Seeds not known.

Phenology: Flowering Apr–May.
Habitat: Cinder soil.
Elevation: 1300–1400 m.

Ariz.

Discussion

Chylismia confertiflora is known only from the type locality on the east side and base of Vulcan’s Throne, Toroweap Valley, Grand Canyon National Monument in Mohave County. P. H. Raven (1962, 1969) assumed this species to be self-incompatible, based on the large flowers with the stigma elevated above the anthers.

A. Cronquist et al. (1997c) treated Chylismia confertiflora as part of C. brevipes, with a comment about the capsule dimensions, and indicated they consider the differences to be one end of the spectrum of a variation within C. brevipes. Although known from very few collections and sparse field data, P. H. Raven (1962, 1969) considered it to be distinct and to be most closely related to C. brevipes and to C. multijuga. He distinguished it from the latter by its larger flowers, nodding inflorescences, and large buds; and from the former by its glandular puberulent sepals, unequal stamens, and uniformly branched habit. In addition, the very restricted range of C. confertiflora is outside (to the east) of the range of C. brevipes. Chylismia multijuga grows within a few miles of the only know locality, but in this area C. confertiflora is very distinct from that species. Further collections and more detailed study of the overall morphological patterns as well as, perhaps, molecular data may clarify whether this is best considered to be an extremely restricted distinct species or a somewhat distinct outlier of the variable C. brevipes.

Selected References

None.

Lower Taxa