1. Needles 2 or 3 in a bundle.
2. Needles in bundles of 3, 12-20 cm long..........................Pinus ponderosa
2. Needles generally in bundles of 2, 2-6 cm long.
3. Cones spreading at right angles or reflexed, the scales armed with prickles...............................Pinus controta (2 varieties)
3. Cones directed towards the apex of the shoot, strongly incurved or divergent, the scales unarmed or armed with minute prickles..................Pinus banksiana
1. Needles usually 5 in a bundle.
4. Cones long-stalked, 15-25 cm long, 6-9 cm thick at maturity; cone scales thin and flexible; seeds prominently winged..........................Pinus monticola
4. Cones sessile or subsessile, 5-25 cm long, cone scales thick, woody, and sometimes remaining closed, seeds wingless or wings short and remaining attached to scale.
5. Cones 8-25 cm long, opening at maturity; scales light brown, thinned somewhat toward the tip...............................Pinus flexilis
5. Cones 5-8 cm long, remaining closed and tardily shedding the seeds at maturity; scales purplish, becoming thickened rather than thinnish toward the tip....................................Pinus albicaulis
Source: The Illustrated Flora of British Columbia
