Tree Species List #2 (web version) (powerpoint version)

ANGIOSPERMAE

Amentiferae:
key feature: inflorescence is ament (monoecious or dioecious)

FAMILIES

Betulaceae
key feature:

aments:preformed male

GENERA

Betula
key feature:

female ament: deciduous bracts (ament shatters when mature)

Alnus
 key feature:

female ament: persistent bracts (ament intact when mature)

Salicaceae
key features: dioecious; fruit a capsule, abundant, very small seeds with long hairs; abundant vegetative propagation

GENERA

Salix
key features

buds: single bud scale

leaves: long, narrow leaves with short petiole

Populus
key features:

buds: several imbricate bud scales
leaves: broad leaves with long petioles

GYMNOSPERMAE

Conifers:
key features: cones

FAMILIES

Pinaceae
key features: bract and cone-scale distinct, flattened; terminally winged seeds

GENERA

Pinus
key features

leaves: persistent, acicular leaves in fascicles
cones: pendent, mostly woody

SUBGENERA

soft pines
key features:

cones: slender, rounded, thin, usually unarmed cone scales
fascicles leaves in 5's fascicle sheath: deciduous
wood: soft, gradual transition from earlywood to latewood

hard pines
key features:

fascicles: leaves in 2's, 3's fascicle sheath: persistent

cones: stout with pricles or spines
wood: hard, abrupt transition from early wood to late wood

Larix
key features:

leaves/twigs/buds: deciduous, linear leaves; spirally attached to long shoots AND short shoots

mature female cone: upright to pendent, leathery