E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
{See also Earthstars Table.} Features include 1) a fruitbody up to 5cm across when the outer covering of the fruitbody has expanded into rays, 2) 4-8 star-like non-hygroscopic rays, which bend back under the spore case, the rays relatively clean, 3) stemless spore case in a bowl-like depression in the center but without a collar or saucer, 4) apical pore at the top of the spore case, often delimited by a circular, raised to depressed line, the pore area often paler or more brownish than the rest of the spore case, 5) spore mass that is white at first but soon brown to purplish brown and powdery, and 6) round, warty spores.

It is found at least in WA (Ramsey), OR (Zeller(2)), CA (Arora), AB (Schalkwijk-Barendsen), and is one of the more common earthstars in the Pacific Northwest (Ammirati), known throughout the United States, and reported also from AZ, FL, KS, MD, MI, MO, NC, NE, and OH, and also Africa, Australia, Canada, the Caribbean, and Europe, (Bates). The University of British Columbia has collections from BC identified as this species (as well as one from CO), and it appears quite commonly on BC foray lists. The University of Washington has collections from WA, MT, and VA.

Outer Surface:
when unopened resembles small puffball: a thickish outer layer and interior spore sac are seen when cut in half; after star-like rays curl back, up to 5cm across with spore case sitting in bowl-like depression at the center; rays pale to brownish on the upper (inner) surface, yellowish buff to brownish on the lower (outer) surface, (Ammirati), round, flattened, or bulb-like at first, the outer wall splitting into 4-8 rays that unfold and bend back under the spore case, (1.5)2-5cm when expanded, rays "not hygroscopic, rather rubbery when fresh, relatively clean and buff to pale tan on underside", upper surface of rays fleshy, pallid becoming pale tan, pinkish, or ocher-brown, sometimes cracking, (Arora), fruitbody 0.6-1.2(2)cm across, 0.8-1.5cm high including the point which is 0.1-0.2cm long, expanding to 2-5cm across as rays open out, outer surface with very little adhering debris, "ochraceous buff to cinnamon buff, spongy-felted"; 4-10 rays, ("often split into 4-6 primary rays, some of which in turn may be split"), "revolute to curved in against the bowl-shaped base", inner fleshy layer of rays "pallid to avellaneous when fresh, drying to near wood brown, thin and forming an even continuous coating over the exposed surface of the rays and bowl, in drying remaining smooth or variously rimose along edge of bowl and on the rays", (Smith(49)), 5-7 rays 1.5-2cm long, (Lincoff)

Inner layer:
spore case papery, unpolished, purplish drab to dull brown; raised mouth-like opening with surrounding circular depression, (Ammirati), spore case 0.5-2cm across, spherical to somewhat flattened, papery, pallid to buff, dull grayish, or brownish, smooth; apical pore "often paler in color and set off from the rest of the spore case by a circular line, ridge, or groove", pore usually raised and fibrillose, (Arora), spore case 0.5-2cm across, spherical to nearly spherical, "papery, purplish drab to wood brown, unpolished", peristome (mouth) "conic, fibrillose, delimited by a circular raised to depressed line", often paler or more brownish than spore case wall, (Smith(49)), peristome delimited by circular raised to depressed line, often paler or more brownish than the spore case wall, fibrillose, (Ramsey), peristome definite, broadly conic, "surrounded by a paler depression or much paler all over", (Coker)

Spore Mass:
white and firm at first, brown to purplish brown and powdery when mature, (Ammirati), brown and powdery when mature, (Arora), coffee color to paler; pseudocolumella well developed, (Smith(49))

Stem:
spore case has no stem (Ammirati, Smith(49))

Odor:
none (Miller)

Microscopic:
spores 3.5-5 x 3.5-5 microns, round, warty, (Arora), spores 3.5-4.5 microns in diameter, (many poorly formed spores in mounts measuring 2.5-3.5 microns), round, verrucose with truncate warts; capillitial hyphae 4-8 microns wide, pale yellowish to brownish, very thick-walled "with much debris incrusting them", often quite crooked, (Smith(49))