Culberson, CF/ Culberson, WL/ Johnson, A 1990: The Ramalina americana complex (Ascomycotina, Ramalinaceae): chemical and geographic correlations. - The Bryologist93(2): 167-186. [RLL List # 140 / Rec.# 3737] Keywords: RAMALINA/ CHEMISTRY/ MEXICO/ DISTRIBUTION/ CHEMOSYNDROMES/ MICROSPECIES
Abstract: 57 figures. 3 tables. [Study of 244 specimens revealed 55 natural products, including 10 new substances, representing several chemotypes. "A biogenetic analysis of the chemotypes suggests an evolutionary origin by loss mutations." One group is centered in Mesoamerica and the other in the SE United States. "The typically apotheciate R. americana complex obviously reproduces primarily by spores, but it never produces spermagonia. Homothallism (selfing) could maintain the integrity of the chemotypes, which may represent a series of microspecies each adapted to its own segment of the total range of the complex."]