Ozarkian Atrichum
Back in early February, I collected a moss that had to be in the genus Atrichum (Polytrichaceae). It was acrocarpous with lanceolate leaves possessing lamellae (gill-like flaps) along the costa (midrib) and had serrate teeth on the margins. But it was a species that I didn’t recognize. There are two species commonly encountered in the Midwest, A. altecristatum and A. angustatum . Both can be readily identified by field characters. This one didn’t match either. Then last Sunday, I collected another Atrichum that looked different. Needing answers I turned to the Flora of North America volume on acrocarpous mosses. In it, I learned that there are only five species of Atrichum in Missouri and that one of these species is restricted to bald cypress swamps in the Bootheel. At this point I thought to myself “if my summation is correct, I have collections of all four Atrichum known from the Ozarks (of Missouri, at least)”. Having been intimidated by bryophyte keys many times before, this t