Geranium
2 of the 7 encyclopedias on this shelf carry an entry for Geranium. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
in ordinary language, a term most frequently applied to any of the cultivated pelargoniums (these belong to the Geraniaceæ, but are not the typical genus); also a book name, and partly a popular one, for the genus Geranium. In botany, the typical genus of the order Geraniaceæ and the alliance geraniales. Geranium sanguineum is a perennial plant with one-flowered peduncles. It is found in dry rocky places, on sandy shores, and on mountains. G. sylvaticum, G. pratense, and G. pyrenaicum are perennial, with two-flowered peduncles. Other common species are G. molle, G. rotundifolium, G. pusillum, G. columbinum, G. dissectum, G. robertianum, and G. lucidum. The root of geranium contains more tannin than quino does, and is a very powerful astringent. The tubers of G. parviflorum are eaten in Van Diemen's Land, where it is called the native carrot. Indian geraniu nium is the name given by perfumers to Andropogon nardus; and the nettle geranium is Coleus fruticosus. GERAR an ancient town or place of the Philistines in the times of Abraham and Isaac, in the S. of Judah, not far from Gaza.
Aiton's Encyclopedia (1910)
an herbaceous flowering plant of both hemispheres. There are over 150 species. The common American woodland geranium is also called crane's-bill from the long, tapering seed pod. The oxalis, or wood sorrel, and the touch-me-not belong to the geranium family. The familiar house plants known as geraniums are closely related, but are really pelargoniums, the distinction being that the flower of the house plant is slightly one-sided, one of the petals having a spur or honey tube running down the flower stalk. Potted geraniums may be put into four divisions: a. Rose geraniums with scented leaves. b. Lady Washington or show geraniums. c. Ivy geraniums with thick, shiny, angled leaves and two-lipped flowers,--a basket plant. d. Ordinary geraniums with zone-marked leaves. Geraniums are propagated best by slips. Take about three inches of the end of a branch, break off the large leaves, and insert half its length in fine earth. Water thoroughly once in a while. Do not keep a geranium water-soaked.