For the purposes of this category, "Pacific" is defined in accordance with the World Geographical Scheme for Recording Plant Distributions (WGSRPD), in which it is considered one of nine botanical continents (Europe, Africa, Asia-Temperate, Asia-Tropical, Australasia, Pacific, Northern America, Southern America, Antarctic).

The WGSRPD further divides the Pacific into four regions: Southwestern Pacific, South-Central Pacific, Northwestern Pacific, and North-Central Pacific.

It includes flora taxa that are native to, or naturalised in, the Pacific region. Taxa that are introduced but not naturalised are excluded. Taxa of the lowest rank are always included. Higher taxa are included only if endemic.