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.

Common Name: HAZELNUT
Habit: Shrub, small tree. Stem: trunk < 6 m; bark smooth or scaly, dark brown; twigs glandular-hairy, becoming glabrous, brown; lenticels small; winter buds ciliate. Leaf: hairy; blade 4--10 cm, oblong to ovate, base oblique-cordate. Staminate Inflorescence: 4--7 cm; bracts each subtending 3 flowers, 3 bractlets. Pistillate Inflorescence: < 1 cm, appearing as terminal bud; bracts each subtending 2 flowers, 6 bractlets. Staminate Flower: sepals 0; stamens 4. Pistillate Flower: sepals 4; stigmas showy, red. Fruit: 1--2 per catkin, each enclosed in a papery involucre of 2 fused bracts, not winged.
Etymology: (Latin: hazelnut, filbert) Note: Flexible stems used in basket-making; some cultivated as food crop.
Reference: Furlow 1997 Syst Bot 26:283--298