Clarkia franciscana
Brittonia 10: 7, fig. 1a, b, d. 1958.
Stems erect, to 40 cm, strigillose. Leaves: petiole 0–5 mm; blade narrowly lanceolate, 1–5.5 cm. Inflorescences racemes, axis straight; buds erect. Flowers: floral tube 1–3 mm; sepals reflexed together to one side; corolla bowl-shaped, petals lavender-pink shading white near middle, base bright reddish purple, fan-shaped, 5–13 mm, apex erose; stamens 8, subequal; ovary cylindrical, 4-grooved, puberulent; stigma not exserted beyond anthers. Capsules 20–40 mm; pedicel 0–15 mm. Seeds gray, 1.2–1.5 mm, scaly, crest 0.2 mm. 2n = 14.
Phenology: Flowering May–Jun.
Habitat: Serpentine soil.
Elevation: 50 m.
Discussion
Clarkia franciscana is an endangered species (designated rare by the California Native Plant Society), restricted to serpentine soils in coastal grass and shrub communities. The only known localities for it are the Presidio in San Francisco County, and the Oakland Hills in Alameda and Contra Costa counties.
Geographic distribution and petal color pattern suggest that Clarkia franciscana may be a self-pollinating derivative of C. rubicunda. If true, enzyme studies indicate that the origin is not recent.
Clarkia franciscana is in the Center for Plant Conservation’s National Collection of Endangered Plants.
Selected References
None.