Louisiana Heron from Birds of America (1827) by John James Audubon, etched by William Home Lizars. Original from University… Free Image from public domain license 
Crested Jay (Pica cristata carulea) from The Natural History of Carolina, Florida, and the Bahama Islands (1754) by Mark… Free Image from public domain license 
Blue Linnet (Linaria caerulea) from The Natural History of Carolina, Florida, and the Bahama Islands (1754) by Mark Catesby… Free Image from public domain license 
Tree from La Botanique de J. J. Rousseau by Pierre-Joseph Redouté (1759–1840). Original from the Library of… Free Image from public domain license 
Cover of A history of the earth and animated nature (1820) by Oliver Goldsmith (1730-1774). Digitally enhanced from our own… Free Image from public domain license 
Wisteria illustration from Bijutsu Sekai (1893-1896) by Watanabe Seitei, a prominent Kacho-ga artist. Digitally enhanced from… Free Image from public domain license 
Morning glory illustration from Bijutsu Sekai (1893-1896) by Watanabe Seitei, a prominent Kacho-ga artist. Digitally enhanced… Free Image from public domain license 
The Bend in the Road (ca. 1900–1906) by Paul Cézanne. Original from The National Gallery of Art. Digitally… Free Image from public domain license 
Flower Beds in Holland (1883) by Vincent Van Gogh. Original from The National Gallery of Art. Digitally enhanced by rawpixel. Free Image from public domain license 
Itea Cyrilla Image from Stirpes Novae aut Minus Cognitae (1784) by Pierre-Joseph Redouté and Charles Louis… Free Image from public domain license 
Mangrove Grape-Tree (Prunus maritima racemosa) and Great horned butterfly (Eruca maxima cornuta) from The natural history of… Free Image from public domain license 
Eranthemum igneum engraved by Benjamin Fawcett (1808-1893) for Shirley Hibberd’s (1825-1890) New and Rare Beautiful… Free Image from public domain license 
Hemionitis Cordata (Heart Fern) from Ferns: British and Exotic (1856-1860) by Edward Joseph Lowe. Original from Biodiversity… Free Image from public domain license 
Attacus Atlas Moth (Attacus Aurora) illustrated by Charles Dessalines D' Orbigny (1806-1876). Digitally enhanced from our own… Free Image from public domain license 
Plantae Selectae: No. 46–Tacamahaca or Balsam Poplar by Georg Dionysius Ehret. Original from The Cleveland Museum of… Free Image from public domain license 
Stuartia Malacodendron Image from Stirpes Novae aut Minus Cognitae (1784) by Pierre-Joseph Redouté and Charles Louis… Free Image from public domain license 
Gayo matsu pine during 1870–1880 by Megata Morikaga. Original from Library of Congress. Digitally enhanced by rawpixel. Free Image from public domain license 
Sempervivum Hirtum (Rolling Hen and Chicks) from Histoire des Plantes Grasses (1799) by Pierre-Joseph Redouté.… Free Image from public domain license 
Peaches (Prunus Persica) (1919) by Royal Charles Steadman. Original from U.S. Department of Agriculture Pomological… Free Image from public domain license 
Sempervivum Arboreum (Tree Houseleek) from Histoire des Plantes Grasses (1799) by Pierre-Joseph Redouté. Original… Free Image from public domain license 
The Botanical Magazine or Flower Garden Displayed: Orange Lily (1807) by Thomas Curtis. Original from The Cleveland Museum of… Free Image from public domain license 
Polypodium Lycopodioides from Ferns: British and Exotic (1856-1860) by Edward Joseph Lowe. Original from Biodiversity… Free Image from public domain license 
Maple Leaves by Shibata Zeshin Original from The MET Museum. Digitally enhanced by rawpixel. Free Image from public domain license 
Branch of Momiji maple tree with leaves and seeds during 1870–1880 by Megata Morikaga. Original from Library of… Free Image from public domain license 
Tsubaki camelia during 1870–1880 by Megata Morikaga. Original from Library of Congress. Digitally enhanced by rawpixel. Free Image from public domain license 
Japanese Bamboo during 1870–1880 by Megata Morikaga. Original from Library of Congress. Digitally enhanced by rawpixel. Free Image from public domain license 
Different types of mollusks illustrated byCharles Dessalines D' Orbigny (1806-1876). Digitally enhanced from our own 1892… Free Image from public domain license