Alpine azalea, Loiseleuria procumbensfrom Traité des Arbres et Arbustes que l’on cultive en France en pleine… Free Image from public domain license 
Tropical tree from Manual Of Geology, Treating Of The Principles Of The Science With Special Reference To American Geological… Free Image from public domain license 
Parcs et Jardins des Environs de Paris (1850) by Victor Petit (1817–1874), an aerial view of botanical gardens near… Free Image from public domain license 
Natural History Ensemble, no. 11 (1596–1610) by Anselmus Boëtius de Boodt. Original from the Rijksmuseum.… Free Image from public domain license 
Natural History Ensemble, no. 1 (1596–1610) by Anselmus Boëtius de Boodt. Original from the Rijksmuseum. Digitally… Free Image from public domain license 
Jonquil illustration from Bijutsu Sekai (1893-1896) by Watanabe Seitei, a prominent Kacho-ga artist. Digitally enhanced from… Free Image from public domain license 
