Populus tremuloides : Trembling Aspen

Scientific Name:

Kingdom: Plantae

Division:

• Tracheophyta (vascular)
• Spermatophyta (seed bearing)
Angiospermae (enclosed seed)

Class: Dicoteldonae (two seed-leaves)

Family: Salicaceae (Willow Family)

Genera: Populus (Poplar) (Lat. classic latin name for poplar trees)

Species: tremuloides (Lat. tremulus=trembling, quivering, referring to the trembling of the leaves in even slightest wind.)

English Name(s):

Trembling Aspen, Quaking Aspen, White Poplar, Mountain Aspen

First Nation Names:

t'oo

Structure:

• Bark smooth chalky white to greenish-white. Bark becoming furrowed on oldest trees.
• Slender tree up to 12 meters tall occasionaly taller, but often much shorter.
• Trunk diameter not usually greater than 30cm.

Leaves:

• 3-7 cm long. by 1-6 cm wide. Ovate, short-acuminate in shape.
• Fresh green above and paler below.
• Have a flat petiole (stalk). This is what allows them to tremble in even the slightest breezes.
• In Yukon often silvery-green in colour by mid-summer due to a widespread leaf miner outbreak.
• Margins finely crenate.

Reproductive Parts:

• Female flowers 5-10mm long.
• Flowers born in drooping catkins.
• Male flowers with 5-12 stamens.
• Trees dioecious (unisexual).

Seed:

• Fruit is a capsule slenderly conic in shape, 3-5mm long.
• Seeds have long hairs and are spread by the wind up to 30 km.

Not to Be Confused With:

• Populus balsamifera is the only other poplar in our area. It can be distinguished by its rougher bark, different shaped leaves, and its round rather than flat petiole (leaf stalk).
• When holding a P.balsamifera (Balsam Poplar) leaf by its petiole (stalk), it will roll between two fingers. The leaf of P.tremuloides (Trembling Aspen) will not roll between your fingers.

Physiology:

• P.tremuloides reproduces primarily vegitatively by suckering (shoots from roots). Trees arrising from suckers are clones of the parent tree.
• All the trees in a Aspen stand maybe clones of a single tree. While they may all look like individual trees, they are all connected underground by thier roots. The largest organism in the world is a clone stand of P.tremuloides( Trembling Aspen).
• Aspen bark has chlorophyhyll (green light collecting pigment) and is photosynthetic.
• One can tell if poplars in a stand are clones or separate trees by the timing of the budding of leaves, bearing of catkins, and colouring of leaves in the autumn. All the trees of a single clone will do these things at the same time as eachother.
• The sunny side of aspen trunks and branches produce a white chalky substance to shield it from to much sun.
• Though every leaf on a tree may be infected by leaf miners. The infection apears to not kill the trees.
• Though the famale trees can produce millions of seeds each year. The seeds are only viable for 3days-3weeks and most will not germinate.

Life Cycle:

• Fast growing tree lives about 80 years.

Seasonal Cycle:

• Catkins apear in the spring well before the leaves.
• Leaves deciuous (dieing back). They turn yellow in autumn before falling off by late September.

Animal Uses:

• In spring the catkins are loved by bees seeking wax.
• In times of need ungulates will eat the bark leaving extensive scars on the lower trunk.
• In Yukon more often than not the leaves of these trees are infected by leaf miners.
• Many ungulates will browse on the tender young twigs and leaves.
• One can see where bears have climbed aspens as their claws scratch deep into the soft bark and leave long grey scars.
• Poplars are the preferred food of beavers.

Habitat:

• Common forest species. Often on dry south facing slopes in central Yukon.

Modern:

Industrial:

• Experiments have shown that they can be grown and harvested every 2 years as a crop; or harvested every 10 years for fuel and fiber; or harvested every 30 years for timber.
• Wood is used comercially for making toothpicks.

Medicinal:

• Astringents salicin and populin in the inner bark undoubtedly draw cuts together and speed healing.
• The inner bark is said to contain a quinine substitute.

Food:

• Leaves contain 20-30% of thier dry weight in protien. A concentrate has been produced from the leaves that is almost as nutritional as meat and can be produced more quickly and cheaply.
• Leaves taste somewhat like spinach and are very nutritious.
• The inner bark can be eaten as emergency food or dried and ground to flour.
• The sap can be drunk or boiled down into a syrup.

Traditional Gwich'in:

Folklore:

Industrial:

Medicinal:

Food:

Traditional Other:

Folklore:

• Acording the the Victorian Language of Flowers these plants symbolize lamentation and fear.
• In many languages the name for P.tremuloides translates as "woman's tongue".
• In Sicily it is cutomary on solstice eve to cut down the tallest poplar and drag it through the village while shouting and beating a drum. A crowd dances and sings around the tree.
• Inner bark was used in a smoking mixture by Plains Indians.
• The aspen is said to have provided the wood for the Cross of Christ and its leaves still tremble remembering His Passion.
• The bark was thought to make women barren if it was drunk with the kidney of a mule.
• The poplar was sacred to Hercules because when bitten by a snake he found a remedy for the poison in its leaves.

Industrial:

• Blackfoot used the trunks for centre poles of cerimonial lodges.
• Cotton from the seeds has been used to make cloth and paper.
• Leaves and twigs dye wool grey, gold and brown.

Medicinal:

• Chippewa would spit in a cut, draw the edge together, chew aspen bark or root and apply it thickly as a poultice as soon as possible.
• Leaf or Bark tea was used for fever, rheumatism or arterial swellings. It was also used as a wash for cuts, wounds, sore arms and legs, gangrenous wounds, eczema, burns, body odour, and even cancer.
• Roots were steeped but not boiled and the tea given every hour to pregnant mothers when close to birthing to reduce excessive flow and premature birth. (Chippewa)

Food: