Psilocarphus oregonus

Nuttall

Trans. Amer. Philos. Soc., n. s. 7: 341. 1840

Common names: Oregon woollyheads or woolly marbles
Endemic
Treatment appears in FNA Volume 19. Treatment on page 459. Mentioned on page 457, 470.

Plants silvery to whitish, densely sericeous to somewhat lanuginose. Stems (1–)2–10, ascending to ± prostrate; proximal internode lengths mostly 0.5–1.5(–2) times leaf lengths. Capitular leaves ± erect, appressed to heads, linear to narrowly oblanceolate, widest in distal 2/3, longest 12–20 mm, lengths mostly 6–12 times widths, (3–)3.5–5 times head heights. Heads ± spheric, largest 4–6 mm. Receptacles unlobed. Pistillate paleae individually visible through indument, longest mostly 1.5–2.7 mm. Staminate corollas 0.7–1.4 mm, lobes mostly 4. Cypselae narrowly ± cylindric, terete, 0.6–1.2 mm.


Phenology: Flowering and fruiting late Mar–mid Aug.
Habitat: Seasonally inundated or flooded clay soils (vernal pool margins, drainages, moist rocky slopes)
Elevation: 10–1800(–2400) m

Distribution

V19-763-distribution-map.gif

Calif., Idaho, Nev., Oreg., Wash.

Discussion

Psilocarphus oregonus occurs from west-central California through most of Oregon to southeastern Washington, western Idaho, and northern Nevada. Relatively narrow-leaved, montane forms of P. tenellus account for reports of P. oregonus from the southern Sierra Nevada to Baja California; further study may show these to be intermediates between the two taxa.

A malformed plant collected in Merced County, California, appears to have been a sterile hybrid between P. oregonus and Hesperevax caulescens (J. D. Morefield 1992c).

Selected References

None.

Lower Taxa

None.

... more about "Psilocarphus oregonus"
James D. Morefield +
Nuttall +
Oregon woollyheads or woolly marbles +
Calif. +, Idaho +, Nev. +, Oreg. +  and Wash. +
10–1800(–2400) m +
Seasonally inundated or flooded clay soils (vernal pool margins, drainages, moist rocky slopes) +
Flowering and fruiting late Mar–mid Aug. +
Trans. Amer. Philos. Soc., n. s. +
Compositae +
Psilocarphus oregonus +
Psilocarphus +
species +