building a Global Consortium of Bryophytes and Lichens as keystones of cryptobiotic communities
Cladonia dimorphoclada
Cladonia dimorphocladaRobbins
Family: Cladoniaceae
Prostrate Thorn Cladonia
[Cladonia caroliniana f. dilatata A. Evans, moreCladonia caroliniana f. dimorphoclada (Robbins) A. Evans, Cladonia caroliniana f. fibrillosa A. Evans, Cladonia caroliniana f. prolifera A. Evans, Cladonia caroliniana f. tenuiramea A. Evans, Cladonia psoromica J. P. Dey]
TYPE. UNITED STATES. NORTH CAROLINA, New Hanover County, Wrightsville, 19.IX.1929, A.W. Evans 218 (H, lectotype designated by Ahti (1973); BM, FH, TUR-V, US, isolectotypes).
Description. Lichenized fungus.
Thallus fruticose (primary thallus not seen). Podetia 1-5 cm tall, 0.4- 2 mm thick, pale yellowish green, with tips slightly browned, forming highly-branched, flattened, loose colonies; branching type irregular, dichotomous and trichotomous, often with many short outgrowths; axils usually closed, in old podetia occasionally perforated. Fertile podetia much thicker, with expanded apical whorls of branchlets that resemble cups; sterile podetia apices acute, slender, erect. Surface matt to slightly shiny, pruinose near tips, uneven, maculate, areolate but not cracked. Podetial wall 150-250 μm; cortex rudimentary, 7-12(-25) μm; medulla 60-170 μm; stereome a network of separate strands, often 70-80 μm in diam., not continuously surrounding inner cavity; in interior surface strands are visible as network of narrow, smooth bands, with spaces between appearing rough or arachnoid. Photobiont trebouxioid alga. Ascomata biatorine apothecia, infrequent, pale brown; ascospores not seen. Pycnidia terminal, containing hyaline jelly; details not studied.
Chemistry. Two chemotypes are recognized, one with usnic acid only (UV-, K-, KC+ gold, C-, PD-), and one with usnic and psoromic acids (K-, PD+ yellow), the latter formerly described as C. psoromica.
Substrate and Habitat. On sandy or mossy soil in sun or partial shade.
Distribution. Neotropical (Mexico, Caribbean), eastern North America; in North Carolina found throughout. The psoromic acid chemotype is found in eastern North America; in North Carolina described from the type locality in Ashe County in the Blue Ridge ecoregion (specimens in DUKE).
Literature
Ahti, T. (1973) Taxonomic notes on some species of Cladonia, subsect. Unciales. Annales Botanici Fennici10: 163-184.
Ahti, T. (2000) Cladoniaceae. Flora Neotropica78: 1-362.
Brodo, I.M., S. Duran Sharnoff & S. Sharnoff. (2001) Lichens of North America. Yale University Press, New Haven & London. 795 pp.