ABW Issues

Acta Botanica Weberi  —  ISSN 2561-9357

No. 2 – 2019

Rare Disjunct Cryptogams in Colorado
(Mosses, Hepatics, and Lichens)

William A. Weber

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Abstract: The concept of rarity is discussed, particularly in regard to disjunct species, eco-niches, habitats, and preservation thereof. A detailed explanatory list of rare disjunct mosses, hepatics, and lichens present in Colorado is provided. The hope is that the species lists presented here will be of practical use to local botanists and amateurs intrigued by cryptogams and their intriguing distributions.

 

 

 

 


No. 1 – 2018

Global Plant Distribution and Continental Drift : Two moss species

William A. Weber and Linna Weber Müller-Wille

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Abstract: Two calcareous mosses are discussed in an attempt to understand their extraordinary global distribution. Both are lowland and coastal species that, surprisingly, also occur rarely at high altitude. One has a far-flung distribution worldwide. The phytogeographical displacements of Grimmia incrassicapsulis and Leptodon smithii have likely taken place over many millennia as the continental plates moved, carrying these mosses to their present positions. Accompanying tectonic forces carried them from coastal areas to the mountains. The most likely period for such displacement to have started is the late Permian to early Triassic when Pangaea began to break apart.

It appears these mosses have remained virtually unchanged over time. Ideas are offered about how they may have escaped the pressures of natural selection.

The theories mentioned are substantiated by Dr. Weber’s personal field experiences collecting and observing mosses, along with their habitats, throughout the world.
Suggestions for further research are proposed.