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Betula

 

 

KingdomPlantaePlants, but not fungi, lichens, or algae
SubkingdomTracheobiontaVascular plants—plants with a “circulatory system” for delivering water and nutrients
DivisionMagnoliophytaFlowering plants, also known as angiosperms
ClassMagnoliopsidaDicotyledons—plants with two initial seed leaves
SubclassRosidaeRoses, legumes, proteas, dogwoods, hydrangeas, mistletoes, euphorbias, grapes, many more
OrderFagalesBirch, she-oak, beech, walnut, bayberry, others
FamilyBetulaceaeBirch family: birches, alders, hazels, hornbeams and hop-hornbeams
GenusBetulaBirch

About plant names...

The Betula genus—birch trees—consists of about 30 species of mid-sized trees. (That’s BET-u-la.) They are widespread throughout the northern hemisphere. Among the most common are several with unmistakable white, papery bark—”birch” means “white, bright; to shine.” Birch bark has several other unusual properties. It has long, horizontal lenticels (essentially air vents). It is remarkably waterproof, persisting for long periods after the death of the tree, and favored for this reason (and for lightness) in the construction of canoes. This same waterproof property makes birch bark excellent kindling for a fire.

Identification: White birch and gray birch both share bright white bark, an unmistakable indicator. Several other birch trees have bark that tends to be shaggy, peeling easily. The table below compares some common species:

 

Betula

Birch (Betula) · 11/26/2011 · Nashua River Rail Trail, East Pepperell, MA
≈ 2 × 1½" (5.4 × 4 cm) Species not yet identified

 
Betula alleghaniensis

Betula nigra

Betula papyrifera
Common Name

Yellow Birch

River Birch

American White Birch
Plant Trees are 60-70' (18-21 m) tall, rarely reaching 100' (30 m). Tree shape is pyramidal in young trees, and usually uneven in mature trees. Trees are up to 82' (25 m), rarely reaching 98' (30 m). They often have multiple trunks. Trees tend to be pyramid-shaped when they are young, becoming more irregular as they age. The paper birch reaches about 60' (18 m) in height, rarely up to twice that. The trunk (sometimes multiply stemmed) is typically bright white, up to 12" (30 cm) in diameter, with a Trees tend to be pyramidal when young, becoming more irregular as they age.
Flowers Yellow birches have both male and female flowers on the same tree. Male flowers are catkins near twig ends, 1" (2.5 cm) long and reddish green. Female flowers point upright. They are ⅝" (1.7 cm) long and reddish-green. Male and female flowers appear on the same tree. Male catkins are up to 3" (7.6 cm) long in April; female flowers are inconspicuous. Both male and female flowers occur on the same tree. Male flowers are catkins 2-4" (5-10 cm) long. Female flowers are also catkins, 1-1½" (2.5-3.8 cm) long.
Leaves Leaves are alternate and unlobed, 2-4½" (6-12 cm) long and half as wide. Leaves are dark green, alternate, unlobed. They are roughly diamond-shaped, with the top half of the diamond more pointed and with doubly serrated edges, while the bottom half is flatter and with smooth edges. Leaves turn yellow in the fall. Leaves are alternate, ovate, with pointed tips; dark green above, pale green below, yellow in the fall.
Stem The yellowish-bronze bark, easily peeled as with other birches, is unique in appearence; the inner bark has a slight odor or wintergreen. Bark is highly variable. As with other birches, it peels away spontaneously (“exfoliates”), making the trunk look ragged. It may be dark gray-brown and scaly, pinkish-brown, or white and papery. Peeling, papery bark. (Compare with gray birch, which rarely peels.) However, young trees consist of a reddish bronze bark that does not peel, and sometimes, especially in western trees, this bark remains thoughout the tree’s life.
Fruit Fruits resemble small cones, ¾-1¼" (1.9-3.2 cm) × ¼-⅜" (6.3-9.5 mm).    
Range/ Zones

USDA Zones: 4-9

Habitats   Floodplains, swamp or river boundaries.  
Type Wild Wild Wild

 

 
Betula papyrifera cv. ‘Renaissance Reflection’

Betula populifolia
Common Name

Paper Birch

Gray Birch
Plant   Trees reach 33' (10 m) in height, often with multiple trunks, and are pyramid-shaped in form.
Flowers   Both male and female flowers are found on the same tree (“monoecious”). Male flowers are yellow-brown, 1-3" (2.5-7.6 cm) long, less than ¼" (6.3 mm) in diameter, usually drooping; female flowers are green, about 1" (2.5 cm) long, ⅛" (4.8 mm) in diameter.
Leaves   Roughly triangular (ovate to deltate or rhombic). They have irregular and sometimes doubled serrations.
Stem   Bark is dark reddish brown when young, white as the tree ages. While white birch bark is a brighter color, and tends to peel easily, gray birch bark is tighter, less likely to peel; and darker, more often interrupted by black markings that are often chevron-shaped.
Range/ Zones

USDA Zones: 3b-7b

USDA Zones: 3-6
Habitats   Swamp and pond margins; open woods; dry sandy or poor quality soils
Type Cultivar Wild

 

Online References:

Betula on Discover Life

Betula on www.treenames.net

Betula on www.salicicola.com

Betula on www.buyshrubszone.com

References:

Sibley, David Allen, The Sibley Guide to Trees, Alfred A. Knopf, 2009

Petrides, George A., Peterson Field Guides: Trees and Shrubs, Houghton Mifflin Co., 1972

Little, Elbert L., National Audabon Society Field Guide to North American Trees, Eastern Region, Alfred A. Knopf, 1980

Little, Elbert L., National Audabon Society Field Guide to Trees, Western Region, Alfred A. Knopf, Inc., 1980

Dirr, Michael A., Dirr’s Hardy Trees and Shrubs, Timber Press, 1997

Symonds, George W. D.; photos by Chelminski, Stephen V., The Tree Identification Book, Harper, 2003

Betula

Yellow Birch (Betula alleghaniensis) · 10/2/2010 · Hackers Trail, Cliff Park, Delaware Water Gap National Recreation Area, PA
≈ 8 × 5" (19 × 13 cm) ID is uncertain

Betula

Yellow Birch (Betula alleghaniensis) · 10/6/2011 · Pack Monadnock, 2200', Peterborough, NH
≈ 8 × 12" (20 × 31 cm)

Betula description by Thomas H. Kent, last updated 16 Aug 2013.

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Betula

River Birch (Betula nigra) · 5/15/2010 · Garden in the Woods, Framingham, MA
≈ 14 × 21" (34 × 52 cm)

Betula

Gray Birch (Betula populifolia) · 3/10/2010 · Nashua River Rail Trail, Groton Center, Groton, MA
≈ 9 × 14" (23 × 35 cm) ID is uncertain

Betula

Gray Birch (Betula populifolia) · 5/2/2010 · Nashua River Rail Trail, Groton Center, Groton, MA
≈ 6 × 4½" (14 × 11 cm)