Most mosses have leaves aranged in tight spirals abound the stem. A few, however, are two-ranked, with two staight rows of leaves directly across one another on the stem. (Note: many creeping mosses that have leaves not in 2 rows look like they do because they have their leaves folded in a manner that gives the stems and branches a flattened apperarance. Do not confuse those "complanate" plants with the ones shown here that are actually two-ranked.)



Fissidens, a moderately large genus with a few extremely common members, is one of the most distinctive mosses. Fissidens is flat, and the leaves have a peculiar anatomy. Like those of irises, the leaves are "equitant," a term pertaining to their similarity in cross-section to a horse and rider. The upper base of each leaf is split (the rider's legs), and the base of the leaf above (the horse) fits deeply into the split.


A great rarity in North America, but locally common in the perpetually moist sandstone rockhouses of southern Ohio is the "sword moss," Bryoxiphium norvegicum.


Sword moss leaves are two-ranked, but not equitant like Fissidens. "Fruiting"  (sporophyte-producing) sword moss plants are virtually unknown in North America.