Summary: {See also Earthstars Table.} The conspicuous field characters are the "sulcate conic peristome, which is not sharply delimited from the spore sac; the sulcate underside of the spore sac, where it joins the relatively long pedicel, and the well-developed mycelial layer" (Smith(49)). Other characters include spores with large warts.
Microscopic: spores 4.2-4.8 microns excluding ornamentation, 6-7 microns including ornamentation, round, coarsely verruculose, warts cylindric or club-shaped, blunt, 0.6-1.2 microns high, 0.4-1.5 microns across, sometimes coalescent, spores dark yellow brown; basidia not seen; capillitial hyphae 3-7 microns wide, "dark yellow-brown to brown, tapered, simple or occasionally forked near the tips, thick-walled with a narrow lumen, smooth or slightly encrusted", (Pegler), spores 4.5-6 microns in diameter, round, bister (dull dark brown), covered with flat-topped colorless warts; capillitial threads 4-7 microns wide, "in KOH the walls sordid yellowish to brownish, in iodine paler and brighter yellow, very evenly tapered to apices, unbranched to sparsely branched", (Smith(49))
Notes: There is a collection from BC at Pacific Forestry Center (DAVFP) determined by Paul Kroeger, and another collection from BC at the University of British Columbia collected and determined by T. Goward. Geastrum pectinatum is widely distributed - and has been reported from MI (Smith(49)), AB (Schalkwijk-Barendsen(1)), ON, NC, NY, OH, SC, (Coker(3)), FL, PA, (Lloyd via Coker(3)), United Kingdom, (Pegler), and HI, Costa Rica, Mexico, Brazil, Belgium, Germany, Ireland, Netherlands, Norway, Sweden, Israel, China, Japan, Turkey, Congo, South Africa, Australia, and New Zealand, (various sources).
Habitat and Range
SIMILAR SPECIES
Geastrum striatum differs most obviously in having a basal collar below the spore case, but the warts on the spores are less elevated and the capillitial hyphae are generally somewhat paler, (Pegler(4)). Geastrum schmidelii is smaller, with a short stalk on the spore case, a less separable outer mycelial layer on the rays, and smaller spores, (Coker(3)). G. schmidelii "is smaller, has a shorter stalk, slightly larger but less coarsely ornamented spores, and occurs in different habitats", (Pegler(4)).
Habitat
usually with conifers, "in woods or parks or at roadsides", occasionally with hardwoods, often gregarious, fall (Pegler)