Icones plantarum or figures, with brief descriptive characters and remarks, of new or rare plants, selected from the author's herbarium - Hooker, Joseph Dalton, 1817 -1911 (Longman, Rees, Orme, Brown, Green, & Longman, etc, 1930)

Iconographia floræ italicæ : ossia, Flora italiana illustrata ... - Crépin, François, 1830 -1903 (Tip. del seminario, 1895)

Idaho's rare vascular flora : bibliography, 1896-1991 - Intermountain Research Station (Ogden, Utah) (U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station, 1992)

Identification notes - Illinois. Natural History Survey Division (Illinois Natural History Survey, 1954)

The identification of trees & shrubs; how to recognize, without previous knowledge of botany, wild or garden trees and shrubs native to the north temperate zone - Makins, F. K. (Dutton, 1937)

Iheringia. Série zoologia - Fundação Zoobotânica do Rio Grande do Sul. Museu de Ciências Naturais. (Museu Rio-Grandense de Ciências Naturais, Divisão de Ciências do Departamento de Ciência e Cultura, Secretaria de Estado dos Negócios da Educação e Cultura do Govêrno do Estado do Rio Grande do Sul, 1997)

Illinois biological monographs - University of Illinois at Urbana-Champaign. (Univ. of Illinois Press, 1939)

Illinois biological monographs - University of Illinois at Urbana-Champaign. (Univ. of Illinois Press, 1960)

Illinois biological monographs - University of Illinois at Urbana-Champaign. (Univ. of Illinois Press, 1997)

Illinois Natural History Survey bulletin - Illinois. Natural History Survey Division (The Survey, 1987)

Illinois Natural History Survey bulletin - Illinois. Natural History Survey Division (The Survey, 2007)

Illinois River Bluffs area assessment - Illinois. Dept. of Natural Resources. (Illinois Dept. of Natural Resources, 1998)

Illinois wild flowers - Eifert, Virginia Louise Snider, 1911 -1966 (1960)

Illustrated botany, containing a floral dictionary and a glossary of scientific terms - Newman, John B. (Fowlers and Wells, 1850)

An illustrated dictionary of scientific terms - Rossiter, William, 1897 (G. P. Putnam's Sons, 1878)

An illustrated encyclopaedia of gardening - Wright, Walter P. (Walter Page), 1864 -1940 (J. M. Dent & sons, ltd, 1911)

An illustrated flora of the northern United States, Canada and the British possessions from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic ocean westward to the 102d meridian - Britton, Nathaniel Lord, 1859 -1934 (C. Scribner's Sons, 1896)

An illustrated flora of the northern United States, Canada and the British possessions, from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic Ocean westward to the 102d meridian - Britton, Nathaniel Lord, 1859 -1934 (C. Scribner's sons, 1913)

An illustrated flora of the northern United States, Canada and the British possessions : from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic Ocean westward to the 102d meridian - Britton, Nathaniel Lord, 1859 -1934 (C. Scribner's sons, 1913)

An illustrated flora of the northern United States, Canada and the British possessions, from Newfoundland to the parallel of the southern boundary of Virginia, and from the Atlantic Ocean westward to the 102d meridian - Britton, Nathaniel Lord, 1859 -1934 (C. Scribner, 1913)

An illustrated flora of the northern United States, Canada and the British possesions from Newfoundland to the parallel of the southern boundary of Virginia and from the Atlantic Ocean westward to the 102d meridian. Vol. 3, Apocynaceae to Compositae, dogbane to thistle - Britton, Nathaniel Lord, 1859 -1934 (C. Scribner, 1898)