The following are pdf versions of wild plant books
that date from before 1920.

Among Rhode Island Wild Flowers, W. Whitman Bailey; 1895 (668 kb)

New England Wild Flowers, W. Whitman Bailey; 1897 (1.03 mb)

Flower Calendar, Roger Williams Park Museum Bulletin, 1911, (1.03 mb)

Wild Flowers of New England, Chester A. Reed, 1912, (1.4 mb)

The following reference on ferns has a list
of updated nomenclature at the end of the key.
Ferns and Evergreens of NE, Edward Knobel, 1895 (3.3 mb)

The following reference is "an enumeration of plants growing without cultivation in the state of Rhode Island."
It is available here with the permission of the
The Internet Archive and the
Claire T. Carney Library,
University of Massachusetts Dartmouth.
Plants of Rhode Island J. L. Bennet, 1888 (5.75 mb)

This book is available with the permission of the
Arnold Arboretum Library
Native Trees of Rhode Island Levi W. Russel, 1900 (7.14 mb)
Note: On page 64 is a photo of a Buttonwood (Sycamore) tree next to the
Betsey Williams Cottage in Roger Williams Park. The tree is still standing.