North American wild flowers - Walcott, Mary Vaux, 1860 -1940 (Smithsonian Institution, 1925)

The North Queensland Naturalist : the journal and magazine of the North Queensland Naturalist Club - North Queensland Naturalists' Club. (The Club, 1990)

Northeastern Area Forest Health Report (1993)

Notable flowers to brighten your garden, 1935 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Bristol Nurseries, Inc, 1935)

Notes upon trees and shrubs adapted to central Illinois : with especial reference to their value in ornamental planting - Gibbs, George, Jr. (1900)

Notizblatt des Königl. Botanischen Gartens und Museums zu Berlin - Engler, Adolf, 1844 -1930 (In Commission bei Wilhelm Engelmann, 1902)

Nouvelles archives du Muséum d'histoire naturelle - Muséum national d'histoire naturelle (France) (Masson et Cie, 1888)

Nouvelles archives du Muséum d'histoire naturelle - Muséum national d'histoire naturelle (France) (Masson et Cie, 1887)

Nova acta Regiae Societatis Scientiarum Upsaliensis - Kungl. Vetenskaps-societeten i Uppsala. (Almqvist & Wiksells, 1905)

November 1931 seed for nurserymen - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Herbst Brothers, 1931)

Novon a journal of botanical nomenclature from the Missouri Botanical Garden - Missouri Botanical Garden. (Missouri Botanical Garden, 2008)

Novorum actorum Academiae Caesareae Leopoldino-Carolinae Naturae Curiosorum - Academia Caesarea Leopoldino-Carolina Naturae Curiosorum. (Friedrich Frommann, 1847)

Number 60 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Augustine & Company, 1925)

Nursery stock and greenhouse products : wholesale list, spring 1931 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Bobbink & Atkins, 1931)

[Nursery stock brokerage list] - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Herbst Brothers, 1928)

Nursery stock of distinction, complete landscape department - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Westminster Nursery, 1937)

Nursery stock of distinction, complete landscape department : price list - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Westminster Nurseries, 1948)

Nursery stock of distinction, complete landscape department - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Westminster Nurseries, 1940)

Nursery stock of distinction, complete landscape department : price list - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Westminster Nurseries, 1947)

Nursery stock of distinction, complete landscape department : price list - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Westminster Nurseries, 1943)

Nursery stock of distinction, complete landscape department - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Westminster Nurseries, 1938)

Oak Park Nurseries - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Oak Park Nurseries, 1947)

Oak Park Nurseries - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Oak Park Nurseries, 1948)

Occasional papers of the Museum of Zoology, University of Michigan - University of Michigan. Museum of Zoology. (University of Michigan, 1922)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1877)

Oesterreichische botanische Zeitschrift (A. Skofitz, 1908)

Offer No. 29 : February 9th, 1929 price list - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Herbst Brothers, 1929)

Offer No. 31 : March 9th, 1929 price list - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Herbst Brothers, 1929)

Offer No. 32 : April 1st, 1929 price list - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Herbst Brothers, 1929)

Offer No. 34 : June 1st, 1929 price list - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Herbst Brothers, 1929)

Die offizinellen Pflanzen und Drogen :eine systematische Übersicht über die in sämtlichen Staaten Europas sowie in Japan und den Vereinigten Staaten von Amerika offizinellen Pflanzen und Drogen mit kurzen erläuternden Bemerkungen - Mitlacher, Wilhelm, 1872 -1913 (C. Fromme, 1912)

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1909)

The Ohio journal of science - Ohio Academy of Science. (Ohio Academy of Science, 1912)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1900)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1904)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1906)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1903)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1907)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1909)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1910)

The Ohio naturalist - Ohio Academy of Science. (Biological Club of the Ohio State University, 1913)

Old Colony Nurseries Incorporated [catalog] : 1840-1915 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Old Colony Nurseries, 1915)

Old friends and new catalogue : trees, flowers, fruits fall, 1920 and winter, 1920-1921 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Hicks Nurseries, 1920)

On the development of Hamamelis virginiana - Shoemaker, Daniel Naylor, 1869 - (1902)

The Oölogist for the student of birds, their nests and eggs - Lattin, Frank H. (Frank H. Lattin, 1915)

Opuscula philolichenum (J. Lendemer, 2004)

Oréades - Instituto de Ciências Biológicas da UFMG. Departamento de Botânica. (Departamento de Botânica, U.F.M.G, 1979)

Origin and history of all the pharmacopeial vegetable drugs, chemicals and preparations with bibliography... Prepared under the auspices of and pub. by the American drug manufacturers' association, Washington, D.C - Lloyd, John Uri, 1849 -1936 (The Caxton press, 1921)

The original Barnes Brothers Nursery Co., established 1890 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Barnes Bros. Nursery Co, 1938)

Ornamental hardy trees, shrubs, plants and bulbs : fall–spring 1945–1946 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (E.C. Robbins, 1945)

Ornamental hardy trees, shrubs, plants and bulbs : spring 1945 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (E.C. Robbins, 1945)

Ornamental plants for immediate effects : autumn 1936 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (E.C. Robbins, 1936)

Ornamental plants for immediate effects : for the autumn of 1937 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Gardens of the Blue Ridge, 1937)

Ornamental plants for immediate effects for the spring of 1938 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (E.C. Robbins, 1938)

Ornamental plants for immediate effects : spring 1937 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (E.C. Robbins, 1937)

Ornamental plants for pleasing landscape effects : price-list for spring 1940 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (E.C. Robbins, 1940)

Ornamental plants for pleasing landscape effects : price list for Autumn 1939 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (E.C. Robbins, 1939)

Ornamental shrubs of the United States, hardy, cultivated - Apgar, A. C. (Austin Craig), 1838 -1908 (American Book Co, 1910)

Ornamental shrubs of the United States (hardy, cultivated) - Apgar, A. C. (Austin Craig), 1838 -1908 (American Book Company, 1910)

Ornamental trees and plants for home grounds and other landscape gardening, fruit trees for commercial orchards and home gardens : No. 127 price list, fall 1927-spring 1928 - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (I.E. Ilgenfritz' Sons & Co, 1927)

O.S.U. naturalist - Ohio State University. Biological Club. (Biological Club of Ohio State University, 1902)

Ouachita National Forest, Arkansas-Oklahoma - United States. Forest Service. Southern Region. (U.S. Govt. Print. Off, 1937)

Our living resources : a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems - United States. National Biological Service. (U.S. Dept. of the Interior, National Biological Service, 1995)

Our native trees and how to identify them : a popular study of their habits and their peculiarities - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner's Sons, 1900)

Our native trees and how to identify them; a popular study of their habits and their peculiarities - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner's Sons, 1917)

Our native trees and how to identify them; a popular study of their habits and their peculiarities - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner's Sons, 1913)

Our native trees and how to identify them; a popular study of their habits and their peculiarities - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner's Sons, 1910)

Our native trees and how to identify them; a popular study of their habits and their peculiarities - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner's Sons, 1912)

Our native trees and how to identify them; a popular study of their habits and their peculiarities - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (Scribner, 1902)

Our northern shrubs and how to identify them : a handbook for the nature-lover - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (Charles Scribner's Sons, 1922)

Our northern shrubs and how to identify them; a handbook for the nature-lover - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (Scribner, 1903)

Our northern shrubs and how to identify them; a handbook for the nature-lover - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner, 1912)

Our northern shrubs and how to identify them; a handbook for the nature-lover - Keeler, Harriet L. (Harriet Louise), 1846 -1921 (C. Scribner, 1903)

Our trees. A popular account of the trees in the streets and gardens of Salem, and of the native trees of Essex County, Massachusetts, with the location of trees, and historical and botanical notes - Robinson, John, 1846 -1925 (Printed by N. A. Horton and Son, 1891)

Our trees, how to know them; photographs from nature - Weed, Clarence Moores, 1864 -1947 (Lippincott, 1936)

Outdoor beauty for your home - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (C.M. Hobbs & Sons, 1928)

Pamphlets on forest protection (1900)

Pamphlets on forestry in Maryland (1900)

Pamphlets on forestry in Nebraska (1900)

Pamphlets on forestry in Ohio (1900)

Pamphlets on forestry in Pennsylvania (1900)

Pamphlets on forestry in Tennessee (1900)

Pamphlets on silviculture (1899)

Papers presented at the Celebration of the Twentieth Anniversary of the New York Botanical Garden, September 6-9, 1915. Published by the aid of the David Lydig Fund, bequethed by Charles P. Daly - New York Botanical Garden (1916)

The parasitic fungi of New Jersey - Schwarze, Carl Alois, 1886 - (New Jersey Agricultural Experiment Stations, 1917)

Parks : a manual of municipal and county parks compiled as a result of a nation-wide study of municipal and county parks conducted by the Playground and Recreation Association of America, in co-operation with the American Institute of Park Executives at the request of the National Conference on Outdoor Recreation - American Institute of Park Executives. (A.S. Barnes & Co, 1928)

Partial list of available native plants - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Nik-Nar, 1941)

Partial list of available native plants - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Nik-Nar, 1950)

Pathological plant anatomy - Küster, E. (Ernst), 1874 -1953 (1913)

Pathologische Pflanzenanatomie. In ihren Grundzügen - Küster, E. (Ernst), 1874 -1953 (G. Fischer, 1916)

Pennsylvania trees - Illick, Joseph S. (Joseph Simon), 1884 -1967 (W.S. Ray, State Printer, 1914)

Pennsylvania trees - Illick, Joseph S. (Joseph Simon), 1884 -1967 (W. S. Ray, State Printer, 1915)

Peonies, hardy garden perennials, ornamental evergreens, shade trees and shrubs : 1933 issue superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Thurlow's and Stranger, Inc, 1933)

Peonies, hardy garden perennials, ornamental evergreens, shade trees and shrubs : 1934 issue superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Thurlow's and Stranger, Inc, 1934)

Peonies, hardy garden perennials, ornamental evergreens, shade trees, shrubs : 1936, superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Cherry Hill Nurseries, 1936)

Peonies, hardy garden perennials, ornamental evergreens, shade trees and shrubs : 1935 issue superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Thurlow's and Stranger, Inc, 1935)

Peonies, hardy garden perennials, ornamental evergreens, shade trees and shrubs : 1930 issue superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Thurlows & Stranger, Inc, 1930)

Peonies, hardy garden perennials, ornamental evergreens, shade trees and shrubs : 1931 issue superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Thurlow's and Stranger, Inc, 1931)

Peonies, hardy garden perennials, ornamental evergreens, shade trees and shrubs : 1923 issue - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Newcomb & Gauss, 1923)

Peonies, hardy garden perennials, ornamental evergreens, shade trees and shrubs : 1932 issue superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Thurlows and Stranger, Inc, 1932)

Peonies, hardy garden perennials, ornamental evergreens, shade trees, shrubs : 1938, superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Cherry Hill Nurseries, 1938)

Peonies, hardy garden perennials, ornamental evergreens, shade trees and shrubs : 1926 issue superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (T.C. Thurlow's Sons, Inc, 1926)

Peonies, hardy garden perennials, ornamental evergreens, shade trees, shrubs : 1937, superseding all previous issues - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Cherry Hill Nurseries, 1937)

Perennials and other hardy ornamental plants - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Cottage Gardens, 1927)

Perennials : deciduous trees, flowering shrubs, evergreens, hardy vines, etc - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Muller-Sealey Co., Inc, 1924)

Perennials for rockgardens, hardy border and general plantings - Henry G. Gilbert Nursery; Seed Trade Catalog Collection. (Cottage Gardens, 1928)

Pharmaceutical botany - Youngken, Heber W. (Heber Wilkinson), 1885 -1963 (P. Blakiston's son & co, 1914)