Here’s the 8 ft pine tree stump in January.
The 2006 fruiting. The plasmodium is oozing out through a vertical crack in the stump.
Four hours later. Note the expansion of the sporangia
One day later. the two lower patches have merged into one.
A closeup of the upper blob in the previous picture. The plasmodium is still moving out of the crack. A close look at the lower blob in the previous picture will show that a sheen of plasmodium surrounds much of that clump too.
A day later, some of the clump has retreated, while other parts are starting to differentiate nto well defined sporangia
This matured clump of sporangia forms the basis for the rest of the Arcyria photographs.
The sporangia are fully mature here. Darker color indicates wetness; lighter color, dryness
Usually the disintegration of the sporangium starts at the top and works down towards the base. The width of each sporangium is about 1 millimeter.
The center part of the patch in this picture was first to produce spores. The residue remaining after the spores disperse is the “capillitium”, This structure provides strength and stability to the inside of the sporangium.
The capillitium has expanded at five-fold over the original sporangium size in this slime mold.
More of the sporangia are bursting a day later.
A closeup showing the different stages of sporangial disintegration, capillitium expansion, and the winnowing of spores
A close-up picture showing the the expansion of the spore-bearing capillitium. Many spores are still held by the capillitium in this picture, making it appear much thicker than it is. The threads of the capillitium are about 0.3 millimeters in diameter
The capillitium has expanded fully and the spores have mostly been exttracted by the wind. The capillitium breaks off at the spore chamber base, which is called the “calyculus”. The calyculi are under 1 millimeter in diameter each is supported on a short stipe.
The caliculus (base of the spore capsule) and stype (stalk) are also made up of spores.
A heavy windstorm is winnowing out the spores, “combing” out the capillitii. The dingy brown end color reflects a total removal of all of the reddish spores from the capillitium. The “stumps" in the foreground are the calyculi remnants of the rest of the sporangia
A few tufts of spore-free capillitium remain in a “stump forest” of caliculi .
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