This section is from the book "The Gardener's Monthly And Horticulturist V26", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
"G. L.," Allegheny City, Pa., writes: " I noticed in a catalogue, trees named thus; Cupressus Lawsoniana, Cerasus Vir-giniana. The four last letters, 'iana,' which are added or connected, are they named in honor of a person or named after some place, and is it of our language? I know the Dutch add ' um,' and some English add 'ii.'"
Plants names follow the rules of the Latin language, and have no relation to anything Dutch or English. Where we say, he, she, or it, the Latin language changes the termination of the word. Usually when a plant's name terminates in a, it indicates the feminine gender, the us masculine, and um the neuter. Case is also indicated by termination. Smith in Latin would be rendered Smithius. If we want to make what in English we should call the possessive case, we simply alter Smithius to Smithii - the rule being to drop the two last letters and substitute an i, and this is why there are sometimes only one, and sometimes two ii's. It is simply owing to whether the third letter from the end was an i or not. While Smithius makes Smithii, Johanus would be Johani. The termination, iana, is used when the name is given more as a matter of honorable association. Cupressus Lawsoni would be the form if Mr. Law-son had found the cypress - Lawsoniana means that he was simply honored by the name, though he had nothing to do with the discovery.
In like manner Virginiana means that the plant is associated with Virginia. In the earlier times most of the knowledge of American plants was derived from botanists or collectors who lived in Virginia. The plants were sent to the old world from there, and hence they became associated with that state.