Wavy-leaved or Sitka Alder Birch Betulaceae Alnus sinuata (Regel) Rydb.
These are sweet-scented shrubs mostly 2-4 meters tall. Young bark is reddish
brown, glandular dotted, but glabrous. The older bark is grayish-black. The
alternately arranged, ovate leaves vary from 3 to 10 cm long. The base is rounded
or cordate, but the apex is acute to slightly acuminate. The margins vary from
serrate-denticulate to strongly sinuate. The upper surface is glabrous, but
the lower surface varies from hairy overall to hairy on only the veins. Both
male and female catkins originate on the current year's growth. The pistillate
catkins are 3-6 per branch. The staminate catkins may grow as long as 10 cm.
The fruits have thin, broad, membranous wings which are usually more than twice
as wide as the nutlet.
Alnus sinuata (Regel) Rydb. Sitka Alder, Wavy-leaved Alder Betulaceae Birch Family
CHARACTERISTICS
shrubs commonly 4-5 , sometimes up to 8 meters tall
bark reddish brown, then becoming gray-black
young growth covered by non-stipitate glands
Unisexual flowers always in unisexual catkins which develop with the leaves
on growth of current year
new twigs generally glabrous
pollen flowers always in pendant catkins
the main bracts subtend 2 smaller bracts which subtend 3-6 flowers
each flower contains 3-4 stamens surrounded by a 4-parted perianth
pistillate flowers are in cone-like catkins because the scales are hardened
and persistent
each hardened scale subtends 2 naked flowers which are subtended by 2 or 3 small
bracts
LEAVES
ovate, 3-10 cm long, acute to sub-cordate at base, acute apex; margins finely
once or twice serrulate, usually sinuate; only slightly paler beneath, hairy
on veins or over entire surface, upper surface usually glabrous.
FLOWERS
develop on current years growth. Staminate catkins up to 10 cm long
the pistillate flowers 3-6 on the same branch in catkins up to 1.5 cm long and
less than 1 cm in diameter, each catkin borne on a stalk 2-3 times as long as
the catkin.
FRUIT
with a thin membranous wing at least ½ as broad as the nutlet
HABITAT
moist woods, streambanks, margins of ponds, open montane slopes up to timberline
DISTRIBUTION
Alaska south to the Cascades and Washington Olympic Mountains, through western
Oregon to mountains of northern California, north central and eastern Washington,
Montana and Idaho in the Rocky mountains of Colorado.
OTHER
too small to of much economic use except for firewood. Dried leaves and bark
were sometimes used to make a decoction for a simple tea and for external washes.
It is astringent, mildly heating and could also be used to “tone”
the small intestinal lining for better food absorption and to aid in fat metabolism.
Even small alders are being utilized in Canada. They are making shavings of
the trunks of both alder and quaking aspen. These are glued together into sheets
called Oriented Strand Board (OSB) which are used for sub-flooring, sub-roofing,
sheeting on houses and for making I beams that are used for rafters, non-squeaking
floor joists and many other uses. The American lumbering industry has not yet
begun manufacturing OSB.