Stephanomeria pauciflora
Stephanomeria lactucina
brownplume wirelettuce, few-flower wirelettuce, prairie skeletonplant, wire-lettuce
creeping wirelettuce, large flower stephanomeria, large-flower wirelettuce, lettuce wirelettuce, woodland wirelettuce
1–5+, divaricately and intricately branched (often forming dense bushes), usually glabrous, rarely tomentose.
single, branches erect or ascending (from near bases), glabrous or sparsely puberulent.
withered at flowering;
basal blades linear-lanceolate, runcinate, 3–7 cm, margins pinnately lobed (faces glabrous);
cauline much reduced and bractlike.
green at flowering;
blades linear-lanceolate, 3–8 cm, margins entire or toothed (teeth remote, faces glabrous or sparsely puberulent).
3–10 mm.
10–50 mm (bracteate).
8–11 mm (phyllaries 4–6, glabrous).
12–14 mm (phyllaries 8–12, glabrous).
5–6.
(7–)8–10.
of appressed bractlets.
of (4–7) appressed bractlets (unequal, lengths to 1/2 phyllaries).
borne singly along branches.
borne singly along branches.
tan, 3.5–5 mm, faces tuberculate, grooved;
pappi of 15–20, usually tan, rarely white, bristles (connate in groups of 2–4, bases persistent), plumose on distal 80%.
light tan, 5–6 mm, faces smooth, grooved;
pappi of 25–30, light tan bristles (sometimes connate in groups of 5–6+, persistent), wholly plumose.
= 16.
= 16.
Stephanomeria pauciflora
Stephanomeria lactucina
Stephanomeria pauciflora generally grows as an intricately branched, often rounded bush. Occasional plants, usually from Arizona, New Mexico, Texas, and southern Utah, have long, flexuous stems and branches, an architecture that resembles one of the typical forms of S. tenuifolia. Some plants of S. pauciflora have white pappi, also typical of S. tenuifolia. It is not known if these plants represent uncommon and unusual individuals or if they are from populations in which all plants have those traits. It is also not known whether such plants of S. pauciflora grow near populations of S. tenuifolia; if so, they may result from interspecific hybridization. That is a possibility; experimental hybrid plants produced by crossing individuals from the two species were about 20% fertile. Such fertility suggests the species are sufficiently compatible that fully fertile segregants with variously intermediate morphologies could be expected where they hybridize in nature. The experimental crosses were made reciprocally between S. pauciflora from Riverside County, California (L. D. Gottlieb 6653), and S. tenuifolia from Wheeler County, Oregon (L. D. Gottlieb 6692); specimens of the six F1 hybrid plants that were produced are deposited at DAV. Plants of S. pauciflora that are densely tomentose throughout are occasionally found, particularly in the deserts of California and Nevada, and have been named S. cinerea or S. pauciflora var. parishii.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Stephanomeria lactucina grows in the Cascade Mountains, Sierra Nevada, and North Coast Ranges. It rarely sets seed. The absence of seed is associated with reduced pollen viability, first reported by A. S. Tomb et al. (1978), who noted that “plants [from Siskiyou County, California] were seed-sterile and produced only 45% stainable pollen.” The ability of pollen to take up acetocarmine dye is a measure of their viability and, consequently, the fertility of the plant. I examined pollen from five randomly selected specimens collected from Oregon and California and found from 2% to 98% stainable pollen, with a mean of 47%. Pollen stainability and seed set have not been studied systematically in this species. Because these traits directly influence fitness and population persistence, further study would likely be rewarding.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
KS Wildflowers
SW CO Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
OR
Flora NW
PNW Herbaria
