A scanning electron microscope study of the spores and selected peristomes of the North American Encalyptaceae (Musci)

Abstract

The eight North American species of Encalypta can be readily distinguished on the basis of spore morphology as viewed in the scanning electron microscope. Descriptions are given of the spores of each species as well as those of Bryobrittonia pellucida. Although the spores of Bryobrittonia closely resemble those of Encalypta procera, Bryobrittonia is easily distinguished from all Encalypta species in having mammillose leaf cells. Based on spore polarity and ornamentation, Encalypta can be divided into three groups, these closely approximating groupings that have been proposed on the basis of peristome characteristics. Of the three peristomes examined, that of E. longicolla appears to consist of whole cells, that of E. brevicolla of both whole cells and cell walls, while the peristome of E. rhaptocarpa consists of cell walls only.