Description: Pine with narrow, pointed crown of slender, nearly horizontal branches turned up at the ends, becoming irregular with age, and with abundant cones remaining closed for many years.

Height: 9-24 m

Diameter: 0.3-0.8 m

Needles: evergreen; three in bundle; 7.5 - 18 cm long; slender, stiff, yellow-green.

Bark: Grey and smooth, becoming dark grey and fissured into large, scaly ridges.

Cones: 8 - 15 cm long; egg-shaped, clustered in many or whorls, stalkless and turned back, shiny yellow-brown; cone-scales raised and keeled, ending in short, stout spine. Blackish seeds about 6 mm long; narrow wing 2.5 - 3 cm long.

Habitat: Forms almost pure stands on poor, coarse, rocky mountain soils.

Range: SW Oregon south to S California; local in N Baja California; at 300 - 600 m in north; 400 - 1200 m, sometimes higher, in south.

The whorls of many knobbly, closed (serotinous) cones help to identify this species. Since the cones may become embedded within the wood of the expanding trunk, this tree has been called "the tree that swallows its cones". When fires kill the trees, cones as old as thirty years are opened by the heat and shed their seeds. The abundant seedlings then begin a new forest. Discovered by Hartweg in 1847 and introduced to the UK the same year. Specimens in the UK have reached 25m in seventy years.

Information: Audubon (1980)

Source: The Conifer Garden

Purchased: one pot-grown tree at about 1.1m, late April 1993

Planted: In US strip at B52G near the northern end, west side. Knobcone Pine doesn't really fit into any of our defined "forest zones", but is too nice a tree not to have. It has been joined by a single specimen of Pinus radiata in a small area which will be "Closed-Cone Pine Forest".

Progress: the tree has looked continually healthy and attractive, but does not seem to be fast growing, reaching 1.6 m by October 1998 and 2.9m by 2004.09.27 - about 20 cm per year. There is some risk that it will become shaded by faster-growing trees nearby, especially the Pinus radiata, which has grown by 4m over the same six year period.

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