F. Ernest Weiss was educated at gymnasia in Heidelberg, Germany, and Neuchatel, Switzerland; the International College at Isleworth, near London; and University College, London. He qualified as Doctor of Science (DSc) at the latter institution. After some time as an assistant professor of botany at University College he was appointed professor of botany in the Victoria University, Manchester, in 1892 and remained there until his retirement in 1930. During 1913-1915 he served the university as vice-chancellor. He was elected a Fellow of the Linnean Society in 1888 and served as its president from 1931 to 1934. From 1911 to 1913 he was president of the Manchester Literary and Philosophical Society. He became a member of the British Association for the Advancement of Science in 1890, and was elected a Fellow of the Royal Society of London in 1917. During 1935-1940 and again during 1941-1946 he served on the council of the Royal Horticultural Society and was awarded its Victoria Medal of Honour in 1947. During his career he published a number of papers in botanical journals. He also wrote a popular book, Plant life and its romance (London, 1928), and translated another by P. Sorauer, A popular treatise on the physiology of plants... (London, 1895).
Weiss visited South Africa in 1905 to attend the joint meetings of the British and South African Associations for the Advancement of Science and did some botanising in the Karoo, Natal and Transvaal. At this time he was a member of the British Association's "Committee for the registration of negatives of photographs of botanical interest". On 30 August he delivered a paper at the joint meeting in Johannesburg on "Botanical photographs as aids to ecological research", pointing out that photographs were useful as accurate records of the aspects and distribution of vegetation at different altitudes, on different geological formations, and under varying conditions of drainage, sunshine, moisture, etc. A summary of the paper was included in the British Association's Report for 1905. After the visit he published his botanical observations in three articles in the New Phytologist. The first two appeared under the general title "Some aspects of the vegetation of South Africa" and dealt with the flora of the Cape Peninsula (1905, Vol. 4, pp. 223-232) and of Natal and the Transvaal (1906, Vol. 5, pp. 1-9). The third, with R.H. Yapp as co-author, was entitled "The Karroo in August: Sketches of vegetation at home and abroad" (Vol. 5, pp. 101-115) and was based on a short visit to Matjesfontein. The species Crassula weissii was named after him by N.E. Brown*. Plants collected by him are in the herbarium at Kew Gardens.