Genus Pinus

Pines

Leaves evergreen, needlelike, mostly in fascicles of 2-5

Mature cones pendant or erect, bracts shorter than scales

Pinaceae family

Larches/Tamaracks

Leaves deciduous, sessile, petiolate on a peg

Mature cones erect, bracts shorter or longer than scales

Pinaceae family

Genus Picea

Spruces

Leaves evergreen, linear, usually 4-sided, sessile on a peg

Mature cones pendant, bracts shorter than scales

Pinaceae family

Genus Pseudotsuga

Douglas-fir

Leaves evergreen, linear, flattened, petiolate

Mature cones pendant, bracts longer than scales and 3-lobed

Pinaceae family

Genus Tsuga

Hemlock
Leaves evergreen, linear, typically flattened, petiolate on a peg, spirally arranged, stomatal banding below
Mature cones pendant, globose to ovoid/oblong, primarily with entire margins

Pineaceae family

Genus Abies

True firs
Leaves evergreen, linear, typically flattened, sessile with no petiole
Mature cones erect, scales and bracts deciduous from central axis

Pinaceae family

Genus Sequoia

Sequoias

Found in coastal California and Oregon

Leaves alternate, linerar, 3/8-1 inch long, 2-ranked

Seed cones elliptical to subglobose

Cupressaceae family

Giant sequoia

Found in interior California

Leaves alternate, scalelike

Seed cones ovoid or oblong

Cupressaceae family

Genus Taxodium

Bald-cypress

Found in riparian sites of southeast U.S.

Leaves alternate, linear and 2-ranked, ¼-5/8 inch long

Seed cones globose

Cupressaceae family

Genus Thuja

Northern white-cedar and western redcedar

Leaf scales flattened and scale-like

Seed cones elliptical, about ½ inch long, with 8-12 thin woody scale/bracts

Cupressaceae family

Genus Chamaecyparis

 (Atlantic) White-cedar

Leaf scales flattened and scalelike

Seed cones globose, ¼-1/2 inch diameter, with 4-8 leathery or dry, peltate scale/bracts

Cupressaceae family

Genus Juniperus

Junipers

Leaves dimorphic, scales opposite and decussate

Seed cones berrylike

Cupressaceae family

Genus Juglans

Walnuts

Nuts have indehiscent husk, shell of nut corrugated

Pith chambered

Juglandaceae family

Genus Carya

Hickories

Nuts usually have a dihescent husk along 4 sutures, shell of nut a smooth and often ribbed

Pith solid and homogeneous

Juglandaceae family

Genus Fagus

Beeches

Leaves deciduous and thin

Nut sharply 3-angular in cross section, 2 within each involucre

Fagaceae family

Genus Castanea

Chestnuts

Leaves deciduous, thin, somewhat leathery

Nut rounded or smooth, 1-3 in each involucres

Fagaceae family

Genus Quercus

Oaks

Fruit is an acorn in a scaly cup with one nut per cup

Fagaceae family

Genus Salix

Willows

Leaves usually several times longer than wide (lanceolate), short-petioled

Buds covered by a single caplike scale, terminal bud absent

Salicaceae family

Genus Populus

Aspens, cottonwoods, and poplars

Leaves usually about as long as wide, long petioles that are usually flattened

Buds covered by several imbricated scales, terminal bud present

Salicaceae family

Cherries

Leaves are alternate and simple with 2 glands on petiole at or near the base of the leaf

Fruit is a one-seeded drupe

Rosaceae family

Maples

Leaves are estipulte, simple, opposite, and usually palmately veined and palmately lobed

Fruit is a double samara united at the base and winged and 1-seeded

 Sapindaceae family

Buckeyes and horsechestnuts

Leaves are estipulate and palmately compound with 9-11 short-stalked leaflets

Fruit is a leathery capsule with 1-6 large seeds, with each seed having a large, light-colored scar

Ashes

Leaves are estipulate, pinnately compound, oppositely arranged, and have an odd number of leaflets

Fruit is a single samara