Skip to content
The Patent Garden

US Plant Patent PP5813

Plum tree (Blue Knight)

PUBLIC DOMAIN

Patent expired November 13, 2004. This plant is in the public domain — anyone may propagate and sell it.

No term adjustment or disclaimer is recorded against this patent, so this is the full statutory term — twenty years from the filing date.

The record

Patent number
PP5813
Filed
November 13, 1984
Granted
December 2, 1986
Expires
November 13, 2004
Inventor
ZAIGER CHRIS F; ZAIGER GARY N; GARDNER LEITH M; ZAIGER GRANT G

No cultivar name of record

This patent does not name the plant. Through the 1980s and early 1990s that was still common: naming every new cultivar only became standard practice as plants began to be marketed under brand names. The grant identifies this one by its number and by a written description instead.

Nothing here is missing from our records: the patent itself states no name. Where one exists we show it, and we do not invent one.

Abstract

A new variety of plum tree which has the following unique combination of features which are outstanding in a new variety: 1. Heavy and regular bearing of uniform fruit throughout the tree. 2. Fruit coloring 2 weeks before maturity. 3. The extreme firmness of fruit and its good shipping characteristics. 4. Uniform coloring of the skin giving the fruit a very attractive appearance.

Show the legal claimThe single numbered claim as granted — the legal text that defines what this patent covers.

The following is claimed: 1. A new and distinct variety of plum tree, as illustrated and described, characterized by its vigorous, upright growth and a heavy regular bearer of medium size, very firm, yellow flesh fruit with an attractive blackish blue skin color; characterized in comparison to Red Beaut, (U.S. Plant Pat. No. 2,539); by having fruit that matures 10 days later, is larger in size, colors 2 weeks before maturity and the tree is more productive and a regular bearer of fruit.

Read the full patent: US Plant Patent PP5813 in full — the complete specification, every figure, and the file history.