Slender Woollyheads

Psilocarphus tenellus is relatively common in the Californian Floristic Province from northwestern Baja California to southwestern Oregon; northward it is scattered to northern Idaho and Vancouver Island, British Columbia. It has been of conservation concern in Canada (J. M. Illingworth and G. W. Douglas 1994b).

Plants greenish to grayish, arachnoid to ± sericeous. Stems (1–)2–10, ascending to ± prostrate; proximal internode lengths mostly 1–2(–3) times leaf lengths. Capitular leaves ± spreading, mostly not appressed to heads, spatulate to obovate, widest in distal ¹/3, longest 6–15 mm, lengths mostly 2–5 times widths, 1.5–2.5(–3) times head heights. Heads ± spheric, largest 3–5.5 mm. Receptacles unlobed. Pistillate paleae individually visible through indument, longest mostly 1.5–2.7 mm. Staminate corollas 0.8–1.5 mm, lobes mostly 5. Cypselae narrowly obovoid, somewhat compressed, 0.7–1.2 mm.

Psilocarphus tenellus has a bioregional distribution that ranges from Baja California north through California and southern Oregon; there a disjunctive populations in Washington State, northern Idaho and on Vancouver Island in British Columbia. This annual is a vernal pool specialist that is often found in grasslands such as prototypical habitats on the Jepson Prairie and Lake Hennessey perimeter areas in California.

Also known by the common name of Slender woolly marbles, this plant is greenish to grayish in color. The growth form is ascending to more or less prostrate. The spatulate to obovate, capitular leaves are generally spreading, mostly not appressed to heads; the leaves are widest in their distal third, with lengths about two to five times widths. Heads are more or less spheric, with the largest of characteristic size 3.o to 5.5 millimeters.

Psilocarphus tenellus is a species of flowering plant in the family Asteraceae known by the common names slender woollyheads and slender woolly marbles. It is native to western North America from far southwestern British Columbia to Baja California, where it grows in seasonally wet habitat, such as vernal pools, as well as coastline and disturbed areas.