Mosses growing by a fumarole in cold subantarctic conditions. A fumarole is a volcanic crack in the Earth's surface. It emits volcanic gases such as steam. Plants colonize ecological niches like this because of warmer temperatures, a water supply (condensing steam and meltwater) and a rich supply of minerals from volcanic rocks. Mosses (phylum Bryophyta) are small plants that lack true roots, woody tissue and flowers. They grow in damp places worldwide. Photographed on Saunders Island, South Sandwich Islands, southern Atlantic Ocean.