[Genus Camissonia and Greek -opsis, resemblance]

Warren L. Wagner

Agassizia Spach, Hist. Nat Vég. 4: 347. 1835, not Chavennes 1833 [Plantaginaceae]; Camissonia Link sect. Holostigma P. H. Raven; Holostigma Spach 1835, not G. Don 1834 [Campanulaceae]

Herbs, usually annual, rarely short-lived perennial, caulescent. Stems prostrate to ascending or erect, often with reddish brown or white exfoliating epidermis. Leaves cauline and often in a basal rosette, alternate; stipules absent; sessile or petiolate; blade margins dentate, denticulate, or serrulate. Inflorescences spikes, erect or nodding at anthesis. Flowers bisexual, actinomorphic, buds erect; floral tube deciduous (with sepals, petals, and stamens) after anthesis, with basal nectary; sepals 4, usually reflexed in pairs, sometimes separately; petals 4, yellow, fading red, with 1+ red dots basally; stamens 8, in 2 unequal series, anthers versatile, pollen shed singly; ovary 4-locular, without apical projection, style glabrous or pubescent distally, stigma entire, subcapitate to subglobose, surface unknown, probably wet and non-papillate. Fruit a capsule, contorted or curled 1 to 5 times, or straight, narrowly cylindrical and thickened proximally, 4-angled (at least when dry), regularly but tardily loculicidally dehiscent, not swollen by seeds; sessile. Seeds numerous, in 1 row per locule, flattened, narrowly obovoid, dull. x = 7.

Species 14 (13 in the flora): w United States, nw Mexico.

Camissoniopsis proavita (P. H. Raven) W. L. Wagner & Hoch is known from northern Baja California, Mexico. It is a diploid, closely related to C. micrantha but differing in having numerous flowers in the basal rosette, which is densely leafy.

All species of Camissoniopsis occur near coasts or on dry slopes or desert flats inland from 0–2500 m. R. A. Levin et al. (2004) found strong molecular support for Camissoniopsis in a clade with Neoholmgrenia and Tetrapteron. Camissoniopsis was segregated from Camissonia as delimited by P. H. Raven (1969). Camissoniopsis is distinguished by having 4-angled fruits, at least when dry, and not swollen by seeds, dull seeds usually smaller than 1 mm, and by flowering from both basal and distal nodes (Raven). Relationships within Camissoniopsis are complex and reticulate. Several diploids (especially C. hirtella) appear to have contributed to the formation of the tetraploids and, in turn, the hexaploids (Raven), and, as a result, are very similar morphologically to each other. Identification of the polyploid species of Camissoniopsis is aided by their pollen having a high proportion of grains with higher number of pores than typical Onagraceae 3-pored pollen, usually 4- or 5-pored. This can be observed under low magnification (for example, 10\×) since the 3-pored pollen is triangular while the 4-pored is quadrangular and 5-pored is pentangular. Raven proposed Camissonia sect. Holostigma as a new combination based on Spach’s generic name. He was unaware that Holostigma Spach, like Agassizia Spach, is a later homonym and thus illegitimate; however, he satisfied all requirements for valid publication of a new sectional name in Camissonia. Reproductive features include: self-incompatible (C. cheiranthifolia and C. bistorta) or self-compatible; flowers diurnal; outcrossing and pollinated by bees (E. G. Linsley et al. 1963, 1964, 1973) or autogamous (Raven).