Key To Maine Conifers

Statements are designed to be read in order. If your specimen doesn't match the first statement, go to the next group or statement. The reverse lettering allows one to determine how many keying statements are present.

D - needles in bundles - pine, tamarack

1d - bundles of > 6; soft & deciduous = Tamarack (European Larch)*

1c - bundles of 5 = White Pine

1b - bundles of 3 = Pitch Pine

1a - bundles of 2

2b - needles > 4"; bark reddish; mottled/blotched; large tree with straight trunk = Red Pine

2a - needles < 2"; cones up to 2"; curved, closed and persistent; irregular growth form = Jack Pine (Scots Pine)**

C - needles flattened; leaves appearing 2-ranked - fir, hemlock, yew

3c - leaves without 2 lines on underside; sprawling shrub = Canada Yew (English Yew)***

3b - twigs opposite; leaves mostly >3/4"; bark with resin blisters; aromatic foliage = Balsam Fir

3a - twigs mostly offset; needles with small stems; leaves mostly <3/4" = Eastern Hemlock

B - needles 4 sided & attached on all sides of the twig - spruce

4b - twigs hairy (use hand lens)

5b - needles blunt; some hairs glandular; cones globose and persistent = Black Spruce

5a - needles (usually) shiny & sharp; abundant non-glandular hairs; cones oblong and shed thru winter = Red Spruce

4a - twigs without hairs (use hand lens)

6b - branches pendant; cones >4 inches and pendant = Norway Spruce

6a - needles blunt; foliage glaucous often with pungent odor = White Spruce

A - needles scale-like or awl-like (or both) - cedar, juniper

7b - shrub

8b - trailing shrub with scale-like leaves = Creeping Juniper

8a - prostrate or upright shrub with sharp awl-like needles = Common Juniper

7a - tree

9b - scale-like leaves hugging the twig

10b - foliage rounded = Atlantic White Cedar

10a - foliage & foliage sprays distinctly flattened = Northern White Cedar

9a - foliage both scale-like (older) and awl-like (younger); foliage sprays not flattened = Eastern Redcedar

 

*European Larch - introduced and rarely naturalized; needles over 1"; cones > 3/4"; lower branches drooping; upland habitat

**Scots Pine - introduced and rarely naturalized; upper trunk bark flaky, orange; needles glaucous, blue-green up to 3 inches (variable in young - up to 4" and bundles of 3 or 4 near tips); cones 1-3 inches with small persistent prickle shedding seeds annually.

***English Yew - introduced and rarely naturalized; can be very large and tree-like; bark thin and scaly, coming off in flakes; needles to 4 cm (vs 2 cm in Canada Yew)

Grouped By Foliage Type

FASCICLED = Jack Pine; Pitch Pine; Red Pine; Scots Pine; White Pine; Tamarack; European Larch

SCALED = Atlantic White Cedar; Northern White Cedar; Creeping Juniper; Eastern Redcedar

AWL-LIKE = Common Juniper; Eastern Redcedar

FLAT = Eastern Hemlock; Balsam Fir; Canada Yew; English Yew

4-SIDED = Black Spruce; Red Spruce; Norway Spruce; White Spruce

 


Nomenclature

CUPRESSACEAE - Cypress Family

Chamaecyparis thyoides - Atlantic White Cedar; southern white cedar; white cedar; swamp cedar; false cedar; juniper

Juniperus communis - Common Juniper; ground juniper; dwarf juniper; prostrate juniper; old field common juniper; mountain common juniper

Juniperus horizontalis - Creeping Juniper; creeping cedar

Juniperus virginiana - Eastern Redcedar; red cedar; aromatic cedar; Virginian juniper; eastern juniper; red juniper; pencil cedar

Thuja occidentalis - Northern White Cedar; eastern white cedar; white cedar; eastern arborvitae; arborvitae; swamp cedar

PINACEAE - Pine Family

Abies balsamea - Balsam Fir; balsam; Canada balsam; eastern fir; blister fir; bracted balsam fir

Larix deciduaEuropean Larch; common larch; Polish larch; alpine larch

Larix laricina - Tamarack; eastern larch; American larch; Alaskan larch; black larch; red larch; hackmatack

Picea abies - Norway Spruce; European spruce; Siberian spruce

Picea glauca - White Spruce; Canada spruce; skunk spruce; cat spruce; western white spruce; Alberta white spruce; Black Hills spruce

Picea mariana - Black Spruce; bog spruce; swamp spruce

Picea rubens - Red Spruce; yellow spruce; West Virginia spruce; eastern spruce

Pinus banksiana - Jack Pine; scrub pine; northern scrub pine; gray pine; black pine; Banksian pine; Hudson Bay pine; Banks pine

Pinus resinosa - Red Pine; northern pine; Norway pine

Pinus rigida - Pitch Pine; candlewood pine; torch pine

Pinus strobus - Eastern White Pine; king's arrow pine; king pine; northern white pine; white pine; Weymouth pine

Pinus sylvestris - Scots Pine; Scotch pine; torch pine; Norway pine; Riga pine; Mongolian pine

Tsuga canadensis - Eastern Hemlock; Canada hemlock; hemlock spruce

TAXACEAE - Yew Family

Taxus canadensis - Canada Yew; American yew; ground hemlock

Taxus baccata - English Yew; European yew; common yew

 


References

Forest Trees of Maine by Maine Forest Service - This lists all trees in Maine but excludes shrubs. In addition to the web version, it is available as a printed book. I suggest the PDFs of the individual species as a basic reference.

Dendrology: Trees with Don Leopold YouTube. Don Leopold is a PhD dendrologist at SUNY ESF in Syracuse. He has produced a series of very short YouTube videos for each of the tree species in NY, many of which are also found in New England.

Gymnosperm Database by Christopher J. Earle. This is a world-wide list of topics on gymnosperm species. Nice tidbits on big trees and ethnobotany. His ‘Bookstore’ and ‘Links’ are exhaustive and worth a peak.

Wikipedia - Conifers (Pinophyta) Really - why wouldn't you start your search here? Excellent information with seemingly endless links, internal & external, to more information than anyone would need.

Silvics of North America (Agriculture Handbook 654) by USDA Forest Service. This online resource is geared toward forestry but has oodles of quality information on all North American tree species. This link goes right to the conifer table of contents - aka species list.

GoBotany by The Native Plant Trust. This link goes right to conifers but is easy to find even from the Native Plant Trust main website. This is an on-line key essentially extracted from ‘Flora Novae Angliae’ by Arthur Haines. It can be used in a variety of ways and usually includes many photos.

Flora of North America (FNA) presents information on the names, taxonomic relationships, continent-wide distributions, and morphological characteristics of all plants native and naturalized found in North America north of Mexico. Pinaceae and Cupressaceae are the conifer families. One can also search by genera. Also available in print as ‘Volume 2: Pteridophytes and Gymnosperms’ for $95.

USDA Plants Database Best reference for legal status, wetland status and a few good photos. Just enter the conifer name at the top left.

Fire Effects information System (FEIS) by United States Department of Agriculture. Geared towards the forestry industry; this government resource provides a synthesized scientific knowledge about fire effects on organisms in the United States. Species Reviews are syntheses of the published literature covering the biology, ecology, and fire effects on plants and animals in the United States. Type in a tree name, scientific or common, and click 'Enter Species'.

Peterson Field Guide To Eastern Trees by George Petrides. I like my very old version of this book a lot. The Sibley guide is also nice but includes the entire US. The Audubon Field Guide to North American Trees: Eastern Region is also pretty good.

Bark: A Field Guide to Trees of the Northeast by Michael Wojtech. A unique field guide to just the bark of trees.

 


Errors, suggests or a key you wish to have posted or adapted for posting? Contact Jeff at info@DigitalNaturalist.info.

last update 2024-Mar-2