Jepson (2012) (APG System)

Order

Fagales

Jepson (1993) (Cronquist System)

Order

Fagales

Plant Relationships

Native Genera:

Alnus
Betula
Corylus

(Alder)
(Birch)
(Hazelnut)

Other Common Genera:

Carpinus
Ostrya

(Hornbeam)
(Hop-hornbeam)

Related Families:

Fagaceae

(Beech, oak, chestnut)

Description

Growth Forms:

All members of Betulaceae are trees.

Branching:

Alternate branching.

Leaves:

Simple leaves with dentate margins.
 

Flowers:

The flowers are catkins at the tips of branches.

Fruit:

Alder and birch produce seed in what appear to be miniature pine cones at the tips of the branches. They are often in clusters of 3 or more.
Corylus produce the commonly known hazelnuts. These look like small acorns in a papery husk.

Growing Conditions

Sun and Exposure:

These plants are shade tolerant, and often grow under a forest canopy. It local conditions are cool or foggy, they grow better in full sun.

Soil and Moisture Requirements:

All members of Betulaceae require deep soil with available moisture, especially in late summer. Alder and birch are restricted to moist sites; hazelnut is somewhat more flexible.

Horticulture and Restoration

Horticultural Comments:

In California, it is difficult to use alder and birch in landscapes, unless you can provide them a consistent irrigation source. Alder can be highly reliable, however, in the proper natural setting.
Hazelnut is a sturdy, reliable landscape plant that would be used as a large shrub or small tree.

Wildlife Habitat:

Hazelnut provides fruit in August and early September.

Restoration Projects:

Alder is widely used in riparian restoration projects, especially within the floodplain. In the right conditions, it establishes easily and grows fairly rapidly.
Hazelnut is not used very often, primarily because it is not found in the habitat types where most restoration occurs. It would otherwise be a very popular plant because it establishes readily and produces wildlife forage.