Whitebark pine

Leaves

Form

• Needles evergreen
• Remaining on tree 4–8 years
• In bundles of 5
• Clustered toward the ends of the twigs
• Stout, stiff
• Slightly curved
• Edges smooth
• Bundle-sheath scales deciduous during 1st season

Length

• 4–9 cm

Colour

• Dark yellowish-green

Buds

Form

• Ovoid, pointed
• Scales loose, overlapping

Length

• 5–10 mm

Colour

• Brown to reddish-brown

Twigs

Form

• Stout, hairy, becoming smooth during 2nd season

Colour

• Reddish-brown becoming grey during 2nd season

Seed cones (mature)

Form

• Globular to ovoid
• Stalkless
• At right angles to the branch

Length

• 5–8 cm

Structure

• 30–50 scales
• Thick, tough, pointed, without prickles

Timing

• Cones open only slightly at maturity, then they are shed

Seeds

Form

• Large, wingless, heavy seed coat

Length

• About 10 mm

Seedlings

Form

• 8–10 cotyledons, toothless

Bark

Form

• Smooth when young
• With age broken into narrow scaly plates 1 or 2 cm thick

Colour

• Chalky-white when young, becoming brown with age
• Inner bark reddish-brown

Wood

Texture

• Moderately soft, light

Colour

• Heartwood pale brown
• Sapwood white

Morphology

• Sapwood narrow

Size

Height

• To 20 m

Diameter

• To 50 cm

Maximum age

• 500 years

Tree form

Forest-grown

Trunk

• Varies according to growing conditions
• At high elevations near the tree line, a spreading, prostrate shrub, often with a few upright, windblown branches that project above the snow line
• At lower elevations, a small, upright, multistemmed tree
• In favourable locations, a single-stemmed tree

Crown

• Branches upswept

Root system

• Deep, spreading through the rocky substrate
• Windfirm

Habitat

Site

• From 1000 m to the tree line
• Rocky soils, rock ledges, cliff faces
• Requires a moist climate
• Often occurs in widely scattered clumps

Light tolerance

• Moderately shade-tolerant

Range

Mountains of British Columbia and Alberta