World Flora Online accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as current, with additional synonyms,[3] and Plants of the World Online 126 species-rank taxa (113 species and 13 nothospecies),[4] making it the largest genus among the conifers.

[16]: 205  The male cones are small, typically 1–5 cm long, and only present for a short period (usually in spring, though autumn in a few pines), falling as soon as they have shed their pollen.

[15][18] The modern English name "pine" derives from Latin pinus, traced to the Indo-European base *pīt- 'resin'.

The genus is divided into two subgenera based on the number of fibrovascular bundles in the needle, and the presence or absence of a resin seal on the scales of the mature cones before opening.

[25] Many of the smaller groups of Pinus are composed of closely related species with recent divergence and history of hybridisation.

This, coupled with low sampling and underdeveloped genetic techniques, has made taxonomy difficult to determine.

[26] Recent research using large genetic datasets has clarified these relationships into the groupings often accepted today.

[24] Pines first appeared during the Early Cretaceous, with the oldest verified fossil of the genus being Pinus yorkshirensis from the Hauterivian-Barremian boundary (~130-125 million years ago) from the Speeton Clay, England.

Wind pollination, long life spans, overlapping generations, large population size, and weak reproductive isolation make breeding across species more likely.

[30] As the pines have diversified, gene transfer between different species has created a complex history of genetic relatedness.

Two recent phylogenies are given below; the differences between them, and other published phylogenies, demonstrate these complications: P. nelsonii P. aristata P. balfouriana P. longaeva P. pinceana P. maximartinezii P. rzedowskii P. quadrifolia P. monophylla P. culminicola P. discolor P. remota P. edulis P. cembroides P. bungeana P. squamata P. gerardiana P. krempfii P. peuce P. lambertiana P. strobus P. chiapensis P. monticola P. flexilis P. strobiformis P. ayacahuite P. albicaulis P. koraiensis P. sibirica P. cembra P. parviflora P. wallichiana P. armandii P. dabeshanensis P. fenzeliana P. mastersiana P. bhutanica P. morrisonicola P. wangii P. kwangtungensis P. dalatensis P. heldreichii P. pinaster P. halepensis P. brutia P. pinea P. canariensis P. roxburghii P. latteri P. merkusii P. resinosa P. nigra P. densiflora P. sylvestris P. mugo P. uncinata P. massoniana P. thunbergii P. luchuensis P. kesiya P. yunnanensis P. densata P. henryi P. tabuliformis P. hwangshanensis P. taiwanensis P. jeffreyi P. coulteri P. torreyana P. sabiniana P. washoensis P. ponderosa P. hartwegii P. engelmannii P. durangensis P. arizonica P. devoniana P. montezumae P. pseudostrobus P. gordoniana P. maximinoi P. radiata P. attenuata P. muricata P. contorta P. banksiana P. virginiana P. clausa P. pungens P. serotina P. rigida P. glabra P. taeda P. echinata P. elliottii P. palustris P. caribaea P. oocarpa P. tecunumanii P. greggii P. patula P. teocote P. lawsonii P. herrerae P. pringlei P. leiophylla P. lumholtzii P. praetermissa P. jaliscana P. luzmariae P. georginae P. nelsonii P. aristata P. balfouriana P. longaeva P. monophylla P. juarezensis P. quadrifolia P. pinceana P. maximartinezii P. rzedowskii P. edulis P. discolor P. johannis P. culminicola P. cembroides P. remota P. bungeana P. gerardiana P. krempfii P. peuce P. strobus P. flexilis P. ayacahuite P. strobiformis P. parviflora P. monticola P. cembra P. lambertiana P. albicaulis P. dalatensis P. pumila P. wallichiana P. koraiensis P. sibirica P. squamata P. morrisonicola P. armandii P. fenzeliana P. kwangtungensis P. bhutanica P. wangii P. heldreichii P. halepensis P. brutia P. pinaster P. pinea P. canariensis P. roxburghii P. densata P. latteri P. kesiya P. nigra P. resinosa P. sylvestris P. mugo P. uncinata P. tropicalis P. hwangshanensis P. massoniana P. merkusii P. densiflora P. thunbergii P. taiwanensis P. yunnanensis P. luchuensis P. tabuliformis P. virginiana P. contorta P. clausa P. maximinoi P. montezumae P. sabiniana P. torreyana P. ponderosa P. gordoniana P. yecorensis P. cooperi P. durangensis P. nubicola P. coulteri P. jeffreyi P. washoensis P. arizonica P. engelmannii P. devoniana P. hartwegii P. pseudostrobus P. patula P. leiophylla P. tecunumanii P. muricata P. radiata P. attenuata P. glabra P. herrerae P. caribaea P. palustris P. echinata P. occidentalis P. praetermissa P. serotina P. rigida P. pungens P. taeda P. elliottii P. teocote P. greggii P. lumholtzii P. jaliscana P. luzmariae P. georginae P. maestrensis P. pringlei P. lawsonii P. cubensis P. oocarpa Pines are native to the Northern Hemisphere, and to a few parts from the tropics to temperate regions in the Southern Hemisphere.

Most regions of the Northern Hemisphere host some native species of pines; they occupy large areas of Boreal forest, and are found all around the Mediterranean Basin.

[36] Various species have been introduced to temperate and subtropical regions of both hemispheres, where they are grown as timber or cultivated as ornamental plants in parks and gardens.

[40] Nutrients from pollen aid detritivores in development, growth, and maturation, and may enable fungi to decompose nutritionally scarce litter.

The seeds are commonly eaten by birds, such as grouse, crossbills, jays, nuthatches, siskins, and woodpeckers, and by squirrels.

Some birds, notably nutcrackers and pinyon jays, are of major importance in distributing pine seeds to new areas.

[41] Pines are among the most commercially important tree species, valued for their timber and wood pulp throughout the world.

Pine wood is widely used in high-value carpentry items such as furniture, window frames, panelling, floors, and roofing.

[46] Many pine species make attractive ornamental plantings for parks and larger gardens with a variety of dwarf cultivars being suitable for smaller spaces.

Pine boughs, appreciated especially in wintertime for their pleasant smell and greenery, are popularly cut for decorations.

Pine needles are also versatile and have been used by Latvian designer Tamara Orjola to create different biodegradable products including paper, furniture, textiles and dye.

Young trees removed during thinning are used for pulpwood or are left in the forest, while most older ones are good enough for saw timber.

[58] A tea is made by steeping young, green pine needles in boiling water (known as tallstrunt in Sweden).

[58] In eastern Asia, pine and other conifers are accepted among consumers as a beverage product, and used in teas, as well as wine.

[62] Pines have been a frequently mentioned tree throughout history, including in literature, art, and in religious texts.

Among them, John Muir,[64] Dora Sigerson Shorter,[65] Eugene Field,[66] Bai Juyi,[67] Theodore Winthrop,[68] and Rev.