Oenothera pallida subsp. trichocalyx
Onagraceae subfam. onagroideae
single to several from base, usually unbranched.
basal rosette usually present at anthesis, 3–5(–7.8) × 0.4–0.8(–1.2) cm;
blade narrowly lanceolate to oblong, margins pinnatifid or dentate.
stipules present or absent.
buds with free tips 0–0.2 mm;
floral tube 20–30 mm;
sepals 10–18 mm;
petals 10–20 mm.
floral tube present or, rarely, absent;
sepals 2 or 4 (very rarely 3), deciduous with floral tube, petals, and stamens;
petals yellow, white, pink, red, rarely in combination.
spreading to reflexed, straight or contorted.
= 14.
Oenothera pallida subsp. trichocalyx
Onagraceae subfam. onagroideae
Subspecies trichocalyx occurs across central to southern Wyoming, eastern Utah, western Colorado, northeastern Arizona, and northwestern New Mexico. Within its range it has slight overlap with subspp. pallida and runcinata. In its purest form, subsp. trichocalyx is the most distinctive phase of Oenothera pallida, but many of the populations have characteristics that approach other subspecies with perennial habit (versus annual) appearing occasionally. Plants that are glabrous, or nearly so, like subsp. pallida, but with apparent short-duration habit and divided leaves like subsp. trichocalyx, occur in southern Wyoming and in the Uinta Basin region of Utah; only more typical plants of subsp. trichocalyx otherwise occur in the region without any current evidence of the presence of subsp. pallida.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Genera 21, species 582 (16 genera, 246 species in the flora).
Onagroideae encompass the main lineage of the family, after the early branching of Ludwigia (R. A. Levin et al. 2003, 2004). This large and diverse lineage is distinguished by the presence of a floral tube beyond the apex of the ovary; sepals deciduous with the floral tube, petals, and stamens; pollen shed in monads (or tetrads in Chylismia sect. Lignothera and all but one species of Epilobium); ovular vascular system exclusively transseptal (R. H. Eyde 1981); ovule archesporium multicellular (H. Tobe and P. H. Raven 1996); and change in base chromosome number from x = 8 in Ludwigia to x = 10 or x = 11 at the base of Onagroideae (Raven 1979; Levin et al. 2003). Molecular work (Levin et al. 2003, 2004) substantially supports the traditional tribal classification (P. A. Munz 1965; Raven 1979, 1988); tribes are recognized to delimit major branches within the phylogeny of Onagroideae, where the branches comprise strongly supported monophyletic groups of one or more genera.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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