Occurrence of Entodon cladorrhizans in Alaska, with Notes on Geographical Distribution of E. concinnus

Abstract

Entodon cladorrhizans (Hedw.) C. Muell. is reported for the first time from Alaska, a major extension of its geographic range. Although common in Europe, E. concinnus (De Not.) Paris was long considered an unusually rare species in North America; however, it is common and widespread in the Brooks Range of Arctic Alaska and on its North Slope. As a consequence of this ex- panded pattern of geographic distribution in North America, E. concinnus is now to be interpreted as an arctic species of northernmost Alaska with disjunct outliers in mountainous areas as far south as North Carolina and New Mexico. This species is also reported for the first time from New Guinea. Since the summer of 1949 I have made extensive collections of bryophytes in several parts of Alaska. A full account of this material will eventually be published. The present paper is restricted to two phytogeographically interesting species repre- sented in the collections, namely, Entodon cladorrhizans (Hedw.) C. Muell. and E. concinnus (De Not.) Paris. The two species are readily distinguished, since E. cladorrhizans has conspicuously complanate-flattened, irregularly branched stems while in E. concinnus the stems are terete, turgid and regularly pinnately branched. They also belong to very different floristic elements. The discovery of Entodon cladorrhizans in Alaska.-In 1949 E. cladorrhizans was collected, new to Alaska, near Palmer and Matanuska in the Matanuska River Valley. Details of these and of two specimens more recently collected in the same area are given below. In the field it was found in abundance and with sporophytes; it had exactly the habit and aspect of E. cladorrhizans in the eastern and midwestern United States.