Camissonia boothii subsp. decorticans (Hook. & Arn.) P.H.Raven

  • Authority

    Raven, Peter H. 1969. A revision of the genus Camissonia (Onagraceae). Contr. U. S. Natl. Herb. 37: 161-396.

  • Family

    Onagraceae

  • Scientific Name

    Camissonia boothii subsp. decorticans (Hook. & Arn.) P.H.Raven

  • Type

    Type: California, 1833, D. Douglas (K; isotypes, BM, GH, NY).

  • Description

    Description - Stems 12-65 mm. long, hollow, with conspicuous, exfoliating white or somewhat pinkish or brownish rhytidome. Plants subglabrous, with strigulose or glandular trichomes in the inflorescence. Capsule nearly straight, curved outward, swollen at base, 1.7-2.3 mm. thick near the base, rapidly tapering upward. Seeds dimorphic, 1.4-2.1 mm. long, 0.5-0.7 mm. (smooth type) or 0.8 mm. (papillose type) thick. Gametic chromosome number, n= 7. Self-incompatible.

  • Discussion

    Camissonia boothii subsp. decorticans is the only member of sect. Eremothera to occur off the deserts, but it still occurs in related, highly xeric communities. Twenty plants of R18326, cited above, were tested for pollen-tube growth following self- and cross-pollination and found to be self-incompatible, as have four from east San Luis Obispo County, California, Kyhos 65-173. This subspecies has not been found growing sympatrically with any other member of the section, but it intergrades with subsp. desertorum at the margins of its range. It is usually found away from the coast, but has been found on the bluffs at Taylor Ranch, 1.5 miles east of the mouth of the Ventura River, Pollard in 1963 (CAS, SBBG). Occasional populations of this subspecies at relatively high elevations in the southern part of its range have somewhat smaller flowers and reddish petals; they have been distinguished as Oenothera rutila or, more recently, Oenothera boothii subsp; rutila. In my opinion, there is no evidence that the various populations with this combination of characteristics had a common origin, and, even if they did, they do not appear to constitute a major geographical race comparable with the other subspecies recognized here.