Ongoing collecting efforts on San Nicolas Island have substantially increased the number of plant species documented from the island. Here we report thirty-one plants previously unrecorded from the island. The list includes six eudicots, one monocot, four liverworts and twenty mosses. Five of these species are understood to be introduced on San Nicolas and the remainder are believed to be native. The native vascular plants are Logfia filaginoides, Cistanthe maritima and Muhlenbergia microsperma. Of the twenty-four new bryophytes, one—Asterella bolanderi—is the first record from the Channel Islands. Specific ecological and locality information are provided for the new vascular plant finds and general patterns of bryophyte richness and ecological preferences are discussed
