--divisions, classes, etc. of the vegetable kingdom, e.g. Algae; Cryptogams; Ferns; Fungi; Lichens; Mosses; Phanerogams; also headings beginning with the word Plant; and names of plants
--subdivision Diseases and pests under individual plants and groups of plants, e.g. Corn--Diseases and pests; and names of specific diseases and pests, e.g. Canker (Plant disease)