Camissonia

Herbs, annual, caulescent; with a taproot. Stems erect, decumbent, or ascending, usually branched from base and distally, epidermis white or reddish brown, often exfoliating. Leaves cauline, proximalmost often clustered near base, alternate; stipules absent; subsessile; blade margins entire, serrulate, or serrate. Inflorescences usually leafy spikes, sometimes racemes, nodding at anthesis, erect in fruit. Flowers bisexual, actinomorphic, buds erect; floral tube deciduous (with sepals, petals, and stamens) after anthesis, with basal nectary; sepals 4, reflexed separately or in pairs; petals 4, yellow, fading red, often with red dots basally; stamens 8, in 2 unequal series, anthers versatile, pollen shed singly; ovary 4-locular, without apical projection, stigma subentire, subcapitate to subglobose, surface unknown, probably wet and non-papillate. Fruit a capsule, straight to flexuous, cylindrical, subterete, regularly, sometimes tardily, loculicidally dehiscent; usually sessile, sometimes pedicellate. Seeds numerous, in 1 row per locule, narrowly obovoid to narrowly oblanceoloid, triangular in cross-section, appearing smooth, glossy. x = 7.

Distribution

w North America, nw Mexico, w South America.

Discussion

Species 12 (11 in the flora).

Species of Camissonia occur in desert scrub, grasslands, or pinyon-juniper woodlands, on brushy or open slopes and flats, washes, and, sometimes, on serpentine barrens, at elevations 0 to 2300 meters. Camissonia campestris and C. kernensis are self-incompatible diploids; C. pusilla and C. sierrae are self-compatible diploids; C. contorta is an autogamous hexa­ploid; the other species are autogamous tetraploids. Identification of the polyploid species of Camissonia is aided by their pollen having a high proportion of grains with more pores, usually 4 or 5, than typical 3-pored pollen in Onagraceae. This can be observed under low magnification (for example, 10\×) since 3-pored pollen is triangular, while 4-pored is quadrangular, and 5-pored is pentangular.

P. H. Raven (1969) delineated a group of four closely related species (Camissonia kernensis, C. parvula, C. pubens, and C. pusilla), marked by having sepals reflexed separately (rather than in pairs), which occur mainly in the Great Basin. Of the remaining species of Camissonia in the flora area, several (C. benitensis, C. campestris, C. integrifolia, C. lacustris, and C. sierrae) have more or less restricted ranges within California, or (C. strigulosa) extend also to Baja Cali­fornia, Mexico, or (C. contorta) to Washington, Idaho, and disjunctly to Vancouver Island, British Columbia. Camissonia dentata (Cavanilles) Reiche is the twelfth species in the genus, dis­junct in western South America from southern Peru southward into Chile and Argentina.

W. L. Wagner et al. (2007) departed significantly from the most recent monograph by P. H. Raven (1969) in the delimitation of Camissonia based on the molecular analysis (R. A. Levin et al. 2004); they recognized eight genera in addition to the much reduced Camissonia: Camissoniopsis, Chylismia, Chylismiella, Eremothera, Eulobus, Neoholmgrenia, Taraxia, and Tetrapteron. Raven noted that Camissonia was the most heterogeneous genus in Onagreae, consisting of sharply distinct sections. He further noted that the capitate or subglobose stigma found in Camissonia, by which he distinguished the genus from the broadly circumscribed Oenothera of P. A. Munz (1965), was also found in Gayophytum, Gongylocarpus Schlechtendal & Chamisso, and Xylonagra Donnell Smith & Rose, thus the primary defining character state for the genus at that time is a plesiomorphy (P. C. Hoch et al. 1993). The redefined Camissonia is morphologically delimited by having subterete capsules that are more or less swollen by seeds, linear to narrowly elliptic leaves, and glossy seeds that are triangular in cross-section and mostly smaller than 1 mm in length; and flowering only at the distal, not basal, nodes; and is without ultraviolet reflectance pattern on petals (Raven). Reproductive features include: self-incompatible (C. campestris, C. kernensis) or self-compatible; flowers diurnal; outcrossing and pollinated by bees (E. G. Linsley et al. 1963, 1963b, 1964, 1973), or autogamous, rarely cleistogamous (Raven).

Selected References

None.

Lower Taxa

Camissonia benitensis, Camissonia campestris, Camissonia contorta, Camissonia integrifolia, Camissonia kernensis, Camissonia lacustris, Camissonia parvula, Camissonia pubens, Camissonia pusilla, Camissonia sierrae, Camissonia strigulosa

Key

1	Sepals reflexed separately.	> 2
1	Sepals reflexed in pairs.	> 5
2	Petals 8–15(–18) mm; sepals 5–9(–11) mm; stigma exserted beyond anthers at anthesis.	Camissonia kernensis
2	Petals 1.5–4 mm; sepals 1.2–3.8 mm; stigma surrounded by anthers at anthesis.	> 3
3	Leaves cauline, none clustered near base, blade margins entire or subentire; plants usually glabrous or densely strigillose, rarely villous proximally, sometimes sparsely glandular puberulent distally.	Camissonia parvula
3	Leaves cauline with some clustered near base, blade margins serrulate or undulate-serrulate; plants moderately to densely villous, usually also glandular puberulent, especially distally.	> 4
4	Leaf blades 0.04–0.2 cm wide; floral tubes 0.8–1.6 mm; sepals 1.2–2 mm; capsules 18–32 mm.	Camissonia pusilla
4	Leaf blades 0.2–0.6 cm wide; floral tubes 1.3–3 mm; sepals 2.2–3.8 mm; capsules (18–)26–50 mm.	Camissonia pubens
5	Stigma exserted beyond anthers at anthesis; sepals 3.5–8(–12) mm; petals (3.5–)5–15.5 mm.	Camissonia campestris
5	Stigma surrounded by anthers at anthesis (except sometimes slightly exserted beyond anthers in C. sierrae); sepals (1.2–)1.6–4(–5.5) mm; petals 2–7 mm.	> 6
6	Leaf blade margins usually entire, rarely with 1 or 2 small teeth; plants densely strigillose distally.	Camissonia integrifolia
6	Leaf blade margins usually sparsely serrulate (C. sierrae sometimes with 1–several small teeth); plants glandular puberulent, usually also villous (except also strigillose in C. strigulosa) distally.	> 7
7	Leaf blades usually lanceolate to narrowly ovate, sometimes elliptic, base rounded.	Camissonia sierrae
7	Leaf blades linear to narrowly elliptic, base cuneate or attenuate.	> 8
8	Plants usually densely strigillose, often also glandular puberulent, especially distally, sometimes glandular puberulent only and glabrate, sometimes also villous near base; sepals 1.6–4 mm; less than 10% of pollen grains 4-pored.	Camissonia strigulosa
8	Plants villous, often also glandular puberulent distally, rarely strigillose and glandular puberulent, if so, more than 30% of pollen grains 4 or 5-pored; sepals 1.6–5.5 mm; less than 10% or more than 30% of pollen grains 4 or 5-pored.	> 9
9	Sepals (3–)3.8–5.5 mm; petals (4–)4.5–7 mm.	Camissonia lacustris
9	Sepals 1.6–4 mm; petals 2.5–4(–5) mm.	> 10
10	Anthers with less than 10% of pollen grains 4-pored; leaves green or slightly bluish green; floral tubes 1.2 mm; plants villous and also glandular puberulent distally; San Benito County and adjacent Fresno and Monterey counties, California.	Camissonia benitensis
10	Anthers usually with more than 30% of pollen grains 4 or 5-pored; leaves usually bluish green; floral tubes 1.6–2.7 mm; plants usually villous throughout, often also glandular puberulent distally, rarely entirely strigillose and glandular puberulent; British Columbia, California, Idaho, Nevada, Oregon, Washington.	Camissonia contorta