Major Groups > Puffballs > Geastrum rufescens


Geastrum rufescens

[ Basidiomycota > Geastrales > Geastraceae > Geastrum . . . ]

by Michael Kuo

Here is a fairly easily identified "earth star," found across North America in a variety of woodland habitats, usually during colder weather. It is fairly large for an earth star, measuring up to about 8 cm across when the arms are spread open. The arms are pinkish to pink, and rather thick-fleshed. The "mouth" of the spore case is indistinct (not grooved, puckered, surrounded by a depression, etc.). And, finally, the undersides of the earth star are covered with whitish mycelium that becomes cracked and mosaic-like, and sloughs away in chunks.

Geastrum vulgatum is a synonym.

Thanks to Ron Kerner for collecting, documenting, and preserving Geastrum rufescens for study; his collection is deposited in The Herbarium of Michael Kuo.


Ecology: Saprobic; growing alone or gregariously under hardwoods or conifers; usually appearing in fall, winter, and spring; widely distributed in North America. The illustrated and described collections are from Illinois and Indiana.

Fruiting Body: At first a round to egg-shaped ball, partially submerged in the substrate, covered with mycelium that picks up dirt and debris; with maturity the outer skin peeling back to form 6–8 pink to pinkish tan, radiating, pointed arms stretching 4.5–7 cm across, composed of fairly tough flesh 2–5 mm thick; undersides of arms covered with whitish material that picks up debris, becomes cracked, and often sloughs off in chunks; spore case 1.5–2.5 cm across, more or less round, sitting on a very short, stem-like base; spore case skin brownish, bald, and papery; developing a perforation or "mouth" that is irregular (i. e., the mouth is roundish or poorly defined, not puckered, without grooves, and without a surrounding depression or pale zone); interior of spore case initially solid and white but soon powdery and brown.

Microscopic Features: Spores 3–5 µm including ornamentation of low, dense spines up to 0.5 µm long; globose; brownish to brown in KOH. Capillitial threads 2–6 µm wide; aseptate; walls smooth or a little rough, 1–2 µm thick; dark olive to brown in KOH.

REFERENCES: Persoon, 1794. (Coker & Couch, 1928; Smith, 1951; Ponce de Leon, 1968; Smith, Smith & Weber, 1981; Breitenbach & Kränzlin, 1986; Bates, 2004; Carlsson & Hæggström, 2005; McNeil, 2006; Zamora et al., 2014; Alves & Cortez, 2016.) Herb. Kuo 11121103, 01041901.

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Geastrum rufescens

Geastrum rufescens

Geastrum rufescens

Geastrum rufescens

Geastrum rufescens

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Kuo, M. (2019, August). Geastrum rufescens. Retrieved from the MushroomExpert.Com Web site: