The Coulter pine or big-cone pine, Pinus coulteri, is a native of the coastal mountains of Southern California and northern Baja California (Mexico). Isolated groves are found as far north as Clearlake Ca on the flanks of Mt Konocti and Black Diamond Mines Regional Preserve. The species is named after Thomas Coulter, an Irish botanist and physician.
The Coulter pine produces the heaviest cone of any pine tree. Although it has a limited range in the wild, it is a popular ornamental tree. Wildlife, especially squirrels, gather the large seeds. They were also once eaten by Native Americans.
The wood is weak and soft, so that the species is little used other than for firewood.
Pinus coulteri is a substantial coniferous evergreen tree in the genus Pinus. The size ranges from 10–24 m (33–79 ft) tall, and a trunk diameter up to 1 m (3.3 ft). The trunk is vertical and branches horizontal to upcurved. The leaves are needle-like, in bundles of three, glaucous gray-green, 15–30 cm (5.9–11.8 in) long and stout, 2 mm (0.079 in) thick.
The outstanding characteristic of this tree is the large, spiny cones which are 20–40 cm (7.9–15.7 in) long, and weigh 2–5 kg (4.4–11.0 lb) when fresh. Coulter pines produce the largest cones of any pine tree species (people are actually advised to wear hardhats when working in Coulter pine groves), although the slender cones of the sugar pine are longer. The large size of the cones has earned them the nickname "widowmakers" among locals.