A Dichotomous Key to Common Evergreen Plants in Central Minnesota


Stephen G. Saupe
Biology Department
College of St. Benedict/St. John�s University
Collegeville, MN 56321

Preliminary Key:

1. Leaves all needle-like, not tightly clasping the stem; bark rarely stringy and fibrous (Pines, Spruces, Firs)

2. Needles fastened together in bundles of 2-5, or borne in large clusters on short spur shoots (in new needles are attached individually)

3 Needles in bundles of 2-5, distinctive spur shoots absent���Pinus (Pines)

3'. Needles in clusters on short spur shoots, usually more than 5 needles per spur shoot ��. Larix (Larches or tamaracks)

2�. Needles all separate, attached individually to the branch

4. Shrubs; cones fleshy and berry-like, blue or red

5. Needles attached in whorls of 3, narrow and sharp-pointed, fine white line on underside of needles �..�.Juniperus (Juniper)

5'. Needles attached to the stem individually, not whorled in groups of three; base of needle runs down stem (decurrent), approximately 2.5 cm long, dark green above, yellowish below; cone red cup-like berry that surrounds a single dark-colored seed; native & cultivated ��.Taxus (Yew)

4'. Trees; cones woody

6. Needles angled in cross-section allowing them to be easily rolled between the fingers; small woody stumps remain on twig when needle is removed, twig without needles is rough to the touch����Picea (Spruces)

6'. Needles flat, do not roll between the fingers; do not leave a prominent raised woody stump on the twig when removed

7'. Needles and cones longer than 1.5 cm

8. Buds pointed, dry and not resinous; needles when removed leave a small raised scar, needles come off around twig like a bottle brush; cone pendant, woody, doesn't disintegrate when mature, a 3-pronged bract sticks out of the cone beneath each scale; native to western US, cultivated in our area��.Pseudotsuga menzesii (Douglas fir)

8'. Buds rounded, resinous; needles when removed leave a flat or slightly sunken round scar in twig, needles very fragrant, needles arranged in more or less a single plane; cone upright, disintegrates on maturity�..Abies (Firs)

7. Needles short, less than 1.5 cm long, underside silvery, with a short petiole; tip of mature trees flexible, bends in an arc like a flag; cones small, less than 2 cm long, terminal; native to SE Minnesota in moist shaded areas, cultivated and barely hardy in our area..�Tsuga canadensis (Hemlock)

1'. Leaves like overlapping shingles that tightly clasp the stem making it appear that the stem is green because the true stem is not visible; (needle-like leaves may also be present), the scaly-like leaves paired; bark often stringy and fibrous (junipers, arborvitae)

9. Foliage fan-like, flattened; leaves all scale-like; cone small (about 1 cm) and woody; native, prefers moist, cool, areas; various cultivars in landscape situations ��Thuja occidentalis (White cedar, Arborvitae)

9'. Foliage not fan-like nor flattened, on thread-like branches; some leaves may be needle-like; cone berry-like, blue; native and cultivated ��.Juniperus (Junipers)

Keys to Species


1. Needles 2.5 - 8 cm long; blue-green in color; cultivated���.A. concolor (White fir)

1'. Needles less than 2.5 cm long; darker green, silvery below

2. Needles conspicuously notched at tip; needles appear densely distributed on twig; bracts extend past the cone scales, curved back; cultivated�..A. fraseri (Fraser fir)

2. Needles not conspicuously notched at tip; needles less densely distributed on twig; bracts rarely extend past cone scales, not recurved; native�..A. balsamea (Balsam fir)

Juniperus (Juniper)

1. Leaves in pairs (opposite); trees or shrubs; cones terminal (at the end of the stem)

2. Tree (and sometime upright shrubs); leaves of two types - juvenile needles are 5-7 mm, adult leaves are scale-like; seeds 1 or 2; native�..J. virginiana (Eastern red cedar)

2'. Shrub, low-growing creeping along ground; leaves mostly needle-like; seeds 3-5; cultivated ��..J. horizontalis (Creeping juniper)

1'. Leaves in threes (whorled), joined at base; shrub, creeping; cones axillary (along sides of stem); native��J. communis (Common juniper)

Larix (Larch or Tamarack)

1. Cones 10-18 scales; leaves 10-25 mm, soft; native, bogs��.L. laricina (Tamarack)

1'. Cones with 20+ scales; cultivated �..L. decidua (European larch)

Picea (Spruce)

1. Needles 2.5 cm or longer

2. Needles sharp-tipped, painful to the touch; bluish; cones 3 inches long, scales with ragged margins; cultivated �.. P. pungens (Colorado blue spruce)

2'. Needles not painful to touch; green; young twigs orange with fine, cobweb-like hairs; branches pendulous; cones 5 inches long, resinous; cultivated��P. abies (Norway spruce)

1'. Needles less than 2.5 cm, 0.8 - 2.0 cm long

3. Twigs and bud scales hairless; needles 8-18 mm; buds rounded; cones 3.5 - 5 cm, scales with smooth margin�.P. glauca (White spruce)

3'. Twigs and bud scales hairy; needles typically shorter, 6-18 mm long; buds rounded; cones 1.5-3.5 cm, purple when young; narrow, steeple-like trees; bogs; native�..P. mariana (Black spruce)

Pinus (Pines)

1. Needles in bundles of five ���P. strobus (White pine)

1'. Needles in bundles of 2-3

2. Needles in bundles of 2 and 3; 4-6 inches long; cones 3-6 inches, scales with a sharp prickle ��P. ponderosa (Ponderosa or Yellow pine)

2'. Needles only in bundles of 2

3. Needles longer than 4 inches

4. Needles slender, flexible, break apart when bent; buds dark colored, orange-reddish; bark reddish, cone 1.5-2.5inches long, no prickle, fallen cones stalkless; native�..P. resinosa (Red or Norway pine)

4'. Needles coarse, stiff, don't break apart when bent but produce an audible snap; buds white; bark gray; cones 2-3 inches, prickle, with a short stalk; cultivated�..P. nigra (Austrian pine)

3'. Needles shorter than 4 inches

5. Shrubs, with upright branching growth form; cultivated; needles 3 - 5 cm long; cone 3 - 5 cm, scales with small prickle��P. mugo (Mugho pine)

5'. Trees; cultivated and native

6. Needles spreading, V-shaped; cone curved, pointed toward tip of branch, remains closed at maturity; bark not orange, brown�..P. banksiana (Jack pine)

6'. Needles twisted; cone not curved or pointed toward branch tip, opens on maturity; bark on older branches distinctly orange�.P. sylvestris (Scotch Pine)

Taxus (Yew)

1. Needles not sharply pointed; native�..T. canadensis (American yew)

1'. Needles acuminate, tapering quickly to a sharp point; cultivated �.T. cuspidata (Japanese yew)


 © Copyright 07/27/2005 by SG Saupe