Grass of Parnassus.

Mode of access: Internet.

Grass and people.

Mode of access: Internet.

Soil Survey of the Grass Valley area, California /

U.S. Department of Agriculture, Bureau of Soils in cooperation with the University of California Agricultural Experiment Station.

Index to grass species,

Mode of access: Internet.

Farm weeds of Canada,

At head of title: Dominion of Canada. Dept. of Agriculture. Branch of the Seed Commissioner.

Outlines of botany. Including a description of mosses, lichens, fungi, ferns, and sea-weeds.

Caption title: First outlines of botany.

The potamogetons (pond weeds) of the British Isles, with descriptions of all the species, varieties and hybrids,

Issued in 15 parts, 1898-1915.