SUMMARYThe habitat of the largest known breeding colony of Pink‐footed Geese(Anser brachyrhynchus)at Thjórsárver vid Hofsjökul is described. These botanical studies were made during the Wildfowl Trust's Second Expedition to Central Iceland during July and August, 1953. The distributions and frequencies of 155 species, sub‐species, varieties and hybrids of vascular plants are given; and 37 of the most common mosses and 8 most common liverworts are listed. The plant communities with which the geese are most associated are analyzed. Several of the species have rarely been recorded before from Central Iceland,Minuartia strictaandLittorella unifiorabeing of special interest. A collection representing all the plants described has been deposited in the British Museum (Natural History),