Geastrum morganii

[ Basidiomycetes > Phallales > Geastraceae > Geastrum . . . ]

by Michael Kuo

This rare earthstar is similar in appearance to the much more common Geastrum saccatum; like that species it is small and features a spore case that appears to be nested comfortably in a small bowl. However, Geastrum morganii has a prominent, lined beak; surfaces that bruise slowly pinkish; and a distinctive reddish to purplish or orangish coating on the outer surface of young specimens.

In North America Geastrum morganii is apparently limited to the Midwest--but its documentation is uneven, and it is not often described; it may have been recorded elsewhere as "Geastrum saccatum" or another species.

Description:

Ecology: Saprobic; growing alone or gregariously under hardwoods; often found near rotting stumps; fall; Midwestern North America.

Fruiting Body: At first a bulb-shaped ball 1-2 cm across, partially submerged in the substrate, with a reddish to purplish or orangish covering that often separates in places to reveal a paler surface underneath; with maturity the outer skin peeling back to form 5-7 pinkish buff, non-hygroscopic arms that bruise slowly reddish when handled and often develop cracks and fissures (sometimes cracking deeply and uniformly to create a small saucer like that of Geastrum triplex); spore case more or less round, smooth or faintly felty, brown to brownish, with a grooved (or at least wrinkled) conical beak; 2-3 cm across when arms are opened; interior of spore case initially solid and white but soon powdery and brown.

Microscopic Features: Spores 3.5-4.5 µ; round; spiny; brownish in KOH. Capillitial threads 4-8 µ wide; hyaline to brownish in KOH; not incrusted.

REFERENCES: Lloyd, 1901. (Coker & Couch, 1928; Smith, 1951; Smith, Smith & Weber, 1981.)

Further Online Information:

Geastrum morganii in Smith, 1951

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Cite this page as:

Kuo, M. (2008, November). Geastrum morganii. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/geastrum_morganii.html