When: 2014-12-20

Collection location: Hunlock Creek, Luzerne Co., Pennsylvania, USA [Click for map]

Who: Dave W (Dave W)

Specimen available

Wondering about the very small size, diameters <= 1cm.


Proposed Names

93% (3)
Recognized by sight: Delineated fibrillose peristome (Astraeus has a non-delineated torn aperture), not hygroscopic, mycelial layer collects a large amount of debris, presence of calcium oxalate crystals on endoperidium, size. The spore sac of Astraeus is sessile, these have a short but noticeable stalk.

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= Observer’s choice
= Current consensus


Add Comment
These seem to grow anywhere they want
By: Bob Chapman (Disciseda)
2014-12-21 12:51:43 PST (-0800)

I find these in the piñon juniper woodlands of New Mexico and Arizona and in the desert amongst mesquite. Sunhede mentions its affinity for calcareous soils.

These are indeed very small. Most of my finds are between 1-3cm. I’ve found some as large as 4cm and as small as 5mm.

I have more collections of these than any other Geastrum. Its often varied appearance has fooled me more than I care to admit. Leading to the abundance of collections.

Here are a few for comparison





I did some checking…
By: Dave W (Dave W)
2014-12-21 07:12:44 PST (-0800)

and the “stalk” separating the spore sac from the base appears to be consistent with the G. minimum proposal.

Note on habitat: poor soil where coal ash had previously been dumped (13 or more years ago).

If anyone is interested in studying these, I saved a few.

Thanks for the details, Disciseda.
By: Dave W (Dave W)
2014-12-20 15:34:42 PST (-0800)

I gather that by “delineated peristome” you refer to the circular “boundary” surrounding the upper surface of the spore sac just below the aperture.

Looking at the second photo down, I see the spore sac sits atop a small “stalk” (middle specimen). So, I’m wondering about your description of a similar trait which points toward Astraeum.