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Betula
BIRCH

Higher Taxonomy
Family: BetulaceaeView DescriptionDichotomous Key

Common Name: BIRCH FAMILY
Habit: Shrub, tree; monoecious. Stem: trunk < 35 m; bark smooth to scaly, peeling in thin layers or not, lenticels present or not. Leaf: simple, alternate, petioled, deciduous; stipules deciduous; blade ovate to elliptic, generally serrate, generally +- doubly so. Inflorescence: catkin, generally appearing before leaves, often clustered; bracts each subtending 2--3 flowers, 3--6 bractlets. Staminate Inflorescence: pendent, +- elongate. Pistillate Inflorescence: pendent or erect, developing variously in fruit (see key to genera). Staminate Flower: sepals 0--4, minute; petals 0; stamens 1--10; pistil vestigial or 0. Pistillate Flower: sepals 0--4; petals 0; stamens 0; pistil 1, ovary inferior or superior, chambers 2, each 1-ovuled by abortion, stigmas 2. Fruit: achene, nut, winged or not, subtended or enclosed by 1--2 bracts.
Genera In Family: 6 genera, 155 species: generally northern hemisphere; some cultivated.
eFlora Treatment Author: John O. Sawyer, Jr.
Scientific Editor: Thomas J. Rosatti.

Betula
Stem: trunk < 30 m; bark smooth or scaly, aromatic, often peeling in thin layers; twigs puberulent, glandular, or both; lenticels prominent; winter buds sessile, 3-scaled. Leaf: glandular-hairy; blade 2--5 cm, wide-elliptic, base +- truncate to tapered. Staminate Inflorescence: 2--7 cm; bracts each subtending 3 flowers, 3 bractlets. Pistillate Inflorescence: 2--3 cm; bracts each subtending 3 flowers, 3 bractlets. Staminate Flower: sepals 4; stamens 2. Pistillate Flower: sepals 0. Fruit: many, in a non-cone-like catkin, not enclosed by bract, winged; bracts lobed, papery, released with but not attached to fruit.
Species In Genus: 50 species: circumboreal. Etymology: (Latin: birch) Note: Important wildlife food; wood used for interior finishing; many species cultivated.
eFlora Treatment Author: John O. Sawyer, Jr.
Jepson Online Interchange
Key to Betula

Previous taxon: Alnus viridis subsp. sinuata
Next taxon: Betula glandulosa

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Citation for this treatment: John O. Sawyer, Jr. 2016. Betula, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=9114, accessed on August 27, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on August 27, 2016.


Betula alleghaniensis var. alleghaniensis
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© 2016 Keir Morse
Betula papyrifera var. papyrifera
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© 2016 Keir Morse
Betula papyrifera var. papyrifera
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© 2016 Keir Morse
Betula X sandbergii
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© 2016 Keir Morse
Betula occidentalis
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© 2008 Steve Matson
Betula papyrifera var. papyrifera
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© 2016 Keir Morse

More photos of Betula in CalPhotos