William Borrer

William Borrer (Henfield, Sussex, 13 June 1781 – 10 January 1862) was an English botanist noted for his extensive and accurate knowledge of the plants of the British Islands.

He travelled extensively around Britain to see and collect plants and lichens, and also once crossed the English Channel to visit Normandy. He was accompanied on some of his travels by William Jackson Hooker and by Charles Cardale Babington. Borrer was particularly interested in lichens, willows, roses and succulents although had a very broad knowledge of plants. He was particularly good at recording plant identifications but often omitted the date and location where the plant was collected. He was also frequently consulted about identifications. He attempted to grow many plant species in his garden so that he could distinguish key identification characteristics without concerns that differences were caused by different habitats. In W. A. Clarke's First Records of British Flowering Plants published in 1897, Borrer was credited as the first to identify 21 species of flowering plants at locations from Cornwall to Caithness. These included Isnardia palustris at Buxted in 1827 and the grass Leersia oryzoides at Henfield Levels in 1844 and several willows. He also identified several marine algae and lichens.