ESC200-Home Page

HOME

Class
Schedule
(with links to lecture outlines)

Assignments

Labs

Species Gallery

Vocabulary

Key Features

HOME PAGE

ESC 200 - Spring 2003
Trees in Our Environment

Prof: Linda Brubaker

SPECIES LIST 2 (web, ppt)

PINACEAE—Pine family

Genus	Leaves/Twigs	Mature female cone
*Picea*	persistent, needle-like, sessile, sharp-pointed leaves; twigs with prominent sterigmata	pendent, leathery
*Tsuga*	persistent, linear, petiolate leaves; small sterigmata	pendant, 1-3 " , leathery
*Larix*	deciduous, linear leaves; spirally attached to long shoots AND short shoots	upright to pendent, ~1", leathery
*Cedrus*	persistent, linear leaves; spirally attached to long shoots AND short shoots	upright, ~4-6", shatter when mature, leathery
*Pseudostuga*	persistent, linear, petiolate leaves, lemon aroma;	pendant, 3-lobed exserted bracts, leathery

Genus Picea--Spruce

Large genus

Most common at high elevations and high latitudes. Very good wood quality. Used to make paper and for musical instruments (sound boards of guitars, dolcimer, piano)

Picea sitchensis: Sitka spruce. Slender, sharp-pointed leaves; very fast growth rate, does not tolerate drought; restricted to Pacific Coast.

Genus Tsuga-- Hemlock

Small genus

Most common at low elevations in temperate latitudes. Requires moist soils, typically late successional

Tsuga heterophylla: western hemlock. (2-ranked leaves, 2 stomatal bands, 1" cones). Low elevation in wetter parts of PNW. Late successional to Douglas-fir. Common in old-growth stands.

Tsuga mertensiana: mountain hemlock. (several-ranked leaves, stomatal bands on both surfaces, 2-3" cones) High elevation in western Cascades and Olympics. Highest elevation conifer where snow is deep.

Genus Larix-- Larch

Medium-sized genus.

Often common in very continental climates (where summers are warm but winters are very cold—like Siberia)

Deciduous habit may allow it to survive the combination of cold winters and warm summers (avoid desiccation in spring when temperatures increase, but ground is still frozen).

VERY INTOLERANT TO SHADE. Early successional (adaptive geometry well-suited for pioneer ecology)

Larix occidentalis: western larch. Cones with exserted bracts. Very thick bark. Mid-elevation, eastern Cascades and northern Rockies. Fire adaptation similar to ponderosa pine.

Genus Cedrus-- true cedars

This genus is native of Europe, Africa and Asia.

Cedrus deodara: native of himalayan Mts-- widely planted as street tree in Seattle-- lines much of Stevens way on UW campus

Genus Pseudotsuga (Douglas-fir):

Key features:

leaves persistent, linear, petiolate

lanceolate buds

cone with 3-pronged exserted bracts

Species: Pseudotsuga menziesii (use key features for genus)

CUPRESSACEAE-- NEW FAMILY

Common name for most species includes the word "cedar" This illustrates the difficulty of using common name, because one name is applied to very different groups of species. Technically, cedar refers to the genus Cedrus (true cedars).

Diagnostic feature of family-- scale-like leaves

Other general expectations of family

soft but durable, decay resistant wood
trunk with strong taper
thin fibrous bark
small branches with arching form
very long lived

Genus	Leaves	Branchlets	Cones (scales)
Thuja	scale-like, decussate, lateral leaves curved inward	flattened, planar foliage	oblong, leathery (basal cone scale attachment)
Chamaecyparis	scale-like, decussate, lateral leaves pointed	flattened, planar foliage	globose, leathery (peltate cone-scale attachment
Juniperus	Dimorphic- 1) scale-like, decussate 2) awlshaped in 3's	4-angled, bushy foliage	globose, fleshy, berry-like (peltate cone- scale attachment)

Genus Thuja:

Small genus: low elevation, late successional. Wood very valuable

Thuja plicata: western redcedar. Low to mid elevation in moist climate of PNW. Wood extremely valuable. Used for shakes, shingles, siding. Very decay resistant. Coastal Native American groups used it extensively: long-houses, long-boats, boxes, utensils, clothing, ceremonial items. Peel bark this time of year.

Genus Chamaecyparis:

Small genus: variable ecology. Late successional

Chamaecyparis nootkatensis: very droopy foliage, flexible branches: adapted to high snow loads. (obnoxious aroma)

Chamaecyparis lawsoniana: widely used as ornamental. (white x’s on back of leaves)

Genus Juniperus: Junipers

Fairly large genus. Generally in arid environments. Shrubs to small trees. "juniper berries"responsible for genus-level identification (Juniperus sp.)

BACK TO
TOP

Contact Linda Brubaker at: lbru@u.washington.edu

[ University of Washington ] [ College of Forest Resources ]