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 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)

An illustrated flora of the Pacific States: Washington, Oregon, and California - Abrams, Le Roy, 1874 -1956 (Stanford University Press, 1951)

An illustrated flora of the Pacific States: Washington, Oregon, and California - Abrams, Le Roy, 1874 -1956 (Stanford University Press, 1960)

An illustrated guide to the flowering plants of the middle Atlantic and New England states (excepting the grasses and sedges) the descriptive text written in familiar language - Stevens, George T. (George Thomas), 1832 -1921 (Dodd, Mead and company, 1910)

Illustrated key to the wild and commonly cultivated trees of the northeastern United States and adjacent Canada; based primarily upon leaf characters - Collins, J. Franklin (James Franklin), 1863 -1940 (Holt, 1912)

Illustrated key to the wild and commonly cultivated trees of the northeastern United States and adjacent Canada; based primarily upon leaf characters - Preston, Howard W. 1859 - (H. Holt and company, 1912)

Illustrated manual of proposed endangered and threatened plants of Utah - U.S. Fish; Wildlife Service (Denver, Colorado, 1979)

Illustrations of South American Plants - Miers, John, 1789 -1879 (H. Bailliere; [etc., etc.], 1849)

Illustrierte Flora von Nord- und Mittel-Deutschland, mit einer Einführung in die Botanik - Potonié, H. (Henry), 1857 -1913 (J. Springer, 1889)

Illustriertes Handbuch der Laubholzkunde :Charakteristik der in Mitteleuropa heimischen und im freien angepflanzten angiospermen Geho¨lz-Arten und Formen mit Ausschluss der Bambuseen und Kakteen - Schneider, Camillo, 1876 -1951 (G. Fischer, 1912)

Illustrirte Garten-Zeitung - Müller, Karl, 1818 -1899 (E. Schweizerbart, 1865)

Impacts of backcountry recreation : site management and rehabilitation : an annotated bibliography - Intermountain Forest; Range Experiment Station (Ogden, Utah) (U.S. Dept. of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station, 1981)

Important western browse plants - Dayton, William A. (William Adams), 1885 - (U.S. Dept. of Agriculture, 1931)

Improving productivity on forests and rangelands : 1980 research accomplishments - United States. Forest Service. (U.S. Dept. of Agriculture, Forest Service, 1981)

In the field : the bulletin of the Field Museum of Natural History - Field Museum of Natural History. (Field Museum of Natural History, 2002)

Incrementa florae phaenogamae Rossicae - Trautvetter, Ernst Rudolph von, 1809 -1889 ([s.l.], 1882)

Index : appendix to flora of the Columbia County area, New York - McVaugh, Rogers, 1909 -2009 (University of the State of New York, 1958)

Index filicum: a synopsis, with characters, of the genera, and an enumeration of the species of ferns, with synonymes, references, &c., &c - Moore, Thomas, 1821 -1887 (W. Pamplin, 1857)

Index herbariorum - International Association for Plant Taxonomy (Published and Distributed for International Association for Plant Taxonomy by New York Botanical Gardens, 1990)