Erasmus Darwin (1807). “The Botanic Garden: A Poem, in Two Parts: Part I. Containing The Economy of Vegetation. Part II. The Loves of the Plants”, p.117
John James Audubon (1835). “Ornithological Biography: Or An Account of the Habits of the Birds of the United States of America; Accompanied by Descriptions of the Objects Represented in the Work Entitled The Birds of America, and Interspersed with Delineations of American Scenery and Manners. 5 Vol. Il. Q.”, p.165
Erasmus Darwin (1807). “The Botanic Garden: A Poem, in Two Parts: Part I. Containing The Economy of Vegetation. Part II. The Loves of the Plants”, p.22