Sargassum occurs. "Sargassum muticum" is a large brown seaweed of the class Phaeophyceae. It grows attached to rocks by a perennial holdfast up to 5 cm in diameter. From this holdfast the main axis grows to a maximum of 5 cm high. The leaf-like laminae and primary lateral branches grow from this stipe. In warm waters, it can grow to 12 m long, however in British waters it gives rise to a single main axis with secondary and tertiary branches that the plant sheds annually. Numerous small 2–6 mm stalked air vesicles provide buoyancy. The reproductive receptacles are also stalked, and
Mary Harriet Bate retains 361 of her plant specimens and the collection includes the rare shrub "Myoporum bateae" and the moss "Bryum bateae" named for her. Also there are the moss "Bryum viridulum" as well as the basidiomycete "Trametes heteromalla" , the alga "Sargassum laevigatum" and the tree "Eucalyptus bosistoana". All these were type specimens for the respective species which she collected. Her algal specimens were identified by Jacob Agardh, the fungal specimens by Mordecai Cooke and the bryophytes by Carl Müller. Bate was only one of Mueller's at least 220 female collectors, although she was one of the more prolific of them.