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Stereocaulon botryosum Ach.
Family: Stereocaulaceae
[Lichen botryosus (Ach.) Lam.,  more]
Stereocaulon botryosum image
Lucy Taylor  
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Primary thallus disappearing; pseudopodetia strongly attached to the ground forming cushions 1-2 cm broad, 5-10 (-11) mm high, the bases 0.3-0.6 mm thick, white with a rosy tinge, the upper parts abundantly branched and the tips becoming capitate sorediate; phyllocladia on upper side of decumbent pseudopodetia, flattened verruciform, glaucous white, confluent, soon disappearing into farinose soredia; cephalodia inconspicuous, imbedded in the tomentum, containing Nostoc. Central medullary layer densely conglutinate, of pachydermatous hyphae 2-3 thick, the lumen 1-1.5 µ, KOH+ yellow, gray or dark yellow-brown in color (with the same KOH reaction); outer hyphae white, forming a thick tomentum 50-90 µ thick of white gelatinous thick-walled hyphae 5-7 µ diameter, on the upper side the algae are in glomerules or more or less continuous; phyllocladia with a cortex 15-25 µ thick, dissolving into soredia, the soredia with a distinct 5 µ thick layer of thick-walled cells. Apothecia and pycnidia not known.

Reactions: axis and phyllocladia K+ yellow.

Contents: atranorin, miriquidic acid, perlatolic acid, and anziaic acid (Lamb 1973).

This species grows on earth. It has been reported from Europe, Iceland, and Greenland (locality not specified) by Lamb (1977) but not yet from the American continent.