The third major patent category is the PLANT PATENT. Such a patent is issued for a new, distinct, invented or discovered, asexually reproduced plant including cultivated sports, mutants, hybrids, and newly found seedlings, other than a tuber propagated plant or a plant found in an uncultivated state, it permits its owner to exclude others from making, using, or selling, or asexually reproducing the plant for a period of up to twenty years from the date of filing of application.

Salient features of plant patents include:

• Plant patents too, do not require maintenance fees.
• The definition of plant here includes the following:
• “ A living plant organism which expresses a set of characteristics determined by its single, genetic makeup or genotype, which can be duplicated through asexual reproduction, but which can not otherwise be "made" or "manufactured."
• “Sports, mutants, hybrids, and transformed plants are comprehended; sports or mutants may be spontaneous or induced. Hybrids may be natural, from a planned breeding program, or somatic in source. While natural plant mutants might have naturally occurred, they must have been discovered in a cultivated area.
• “Algae and macro fungi are regarded as plants, but bacteria are not.”

The other categories of patents are listed hereunder:

1. A Reissue Patent is issued to set right an error in an already issued patent; it however will not affect the period of protection offered by the original patent.

2. A Defensive Publication (DEF) is issued instead of a regular patent to offer limited protection, defensive in nature and prevent others from patenting an invention, design, or plant. Since 1986, the Statutory Invention Registration has replaced DEF.