This is a genus that is still in debate by taxonomists around the world. Most agree to include about 175 species but there are another 30 or more that are in dispute as to whether they belong in the genus.

Perhaps the key characteristic to help gardeners identify pines from other needled evergreens is that they bear their needles in groups of 2, 3 or 5 rather than having individual needles emerge directly from the stem as in the spruces (Picea) and firs (Abies).