Tree 15 - 24 m tall, trunk diameter 45 cm - 1 m Bark: pinkish gray to almost black, thick, becoming coarse with age. Older trunks deeply fissured and flaking. Twigs: stiff, yellowish brown to olive-brown, becoming darker with age. Buds: reddish brown, 1.2 - 2 cm long, cylindrical, slightly pointed, with a white resin coating. Form: uniformly pyramidal. Pollen cones: yellow, about 2 cm long, cylindrical, and clustered at the base of new shoots. Needles: in clusters of two, dark green, 8 - 16 cm long, incurved, sharp-pointed, thin, and flexible (won't snap apart when bent). Young seed cones: red, small, cylindrical, at the tips of new shoots. Pollination between cones occurs in May and June. Mature seed cones: woody, stalkless, upright, shiny yellowish brown, 5 - 8 cm long, and egg-shaped. Scales smooth with a deciduous prickle on the thickened apex. Seeds reddish brown, 6 mm long, with wings 1.5 - 2 cm long.
Similar species: The similar P. resinosa differs by having needles that snap apart when bent and brown seed cones that lack prickles.
Habitat and ecology: Introduced from Europe. Normally occurs in mesic woods and upland dunes, but does not occur naturally in the Chicago Region. The population at Illinois Beach State Park in Lake County, Illinois, was planted in the 1860's in an effort to stabilize the dunes.
Occurence in the Chicago region: non-native
Notes: Commonly used for landscape and shade purposes, being hardy and easily transplanted when small. Often planted along highways for its tolerance of air pollution, salt spray, and dry soils. There are many geographic varieties. Diplodia needle-cast disease is common.
Etymology: Pinus is the Latin word for pine. Nigra means black.