Quaking Aspen, White Poplar, Popple
Populus tremuloides
by Martin (Mort) Schmidt for Simply Living
Quaking Aspen isn’t especially tall, generally under 80 feet. But this diminutive tree might be the largest living organism, and it has the broadest range of any North American tree.
Quaking Aspen (Populus tremuloides) has simple leaves that are alternately-arranged. Simple leaves are attached directly to permanent parts of the tree, whereas compound leaves have multiple leaflets sharing a stem (petiole), which typically falls off at the end of the year. Alternately-arranged leaves and branches are not attached directly across from each other, while oppositely-arranged leaves and branches are.
The small, nearly round leaves are 1.5 to 2.5 inches long, and palmately-veined. Small leaves are commonly found on trees exposed to cold, and Quaking Aspen is among the northern-most trees of North America. Palmately-arranged veins radiate from the leaf’s base, whereas pinnately-veined leaves have a single primary vein with secondary veins attached at various points along its length. The leaf of Populus tremuloides has small teeth, and a flat stem oriented perpendicular to the blade. With its flat stem longer than the blade, and the blade’s nearly circular shape, the leaf quivers in the slightest wind. As is true of Eastern Cottonwood (Populus deltoides), quaking might be a way of controlling moisture levels.
Like most or all members of genus Populus, P tremuloides is dioecious, i.e., it has separate male and female trees. This prevents the tree from self-pollinating. Quaking Aspen flowers take the form of catkins and are wind-pollinated. Seeds may be produced in trees as young as three years old. The seeds are exceedingly small – approximately 3 million per pound. Their small size means that they can be produced in huge numbers, but the lack of stored food gives each seed a small probability of succeeding. P. tremuloides propagates primarily via shoots, and entire thickets of trees might share a single root system.
According to the USDA Plants Database, “The staminate-pistillate [male-female] ratio of clones is 1:1 in most localities, but in the eastern US staminate trees may outnumber pistillate ones by 3:1. Some clones alternate between staminate and pistillate forms in different years or produce combinations of perfect [male and female in the same flower], staminate, and pistillate flowers”.
Quaking Aspen bark is bright white, with black knots and horizontal lines. The bark is covered with a thin, powdery substance made of mature bark cells. By shedding its outer bark, Populus tremuloides can photosynthesize with its inner bark, even in winter when leaves are absent. The powder apparently contains naturally-occurring yeast, and can be used as a starter for sourdough bread.
Mature Quaking Aspens typically have a height of 40 to 70 feet and a trunk diameter of approximately 1.5 feet. Neither the Champion Trees of Ohio nor the Monumental Trees of the U.S. website lists a tallest or largest Quaking Aspen, perhaps because they often grow in dense thickets, making it difficult to distinguish single trees. But while individual trees are not particularly large, the Earth’s largest organism is, by some accounts, a Quaking Aspen. Pando, located in Sevier County, Utah, covers 106 acres, but its estimated 47,000 trunks have the same DNA. (Some claim that the largest organism is an underground fungus. But then, there are three best, biggest, or first of everything, depending on how you define it). Individual trees typically live for under 100 years in the East, or 150 years in the dryer West, but Pando’s root system is estimated to be over 80,000 years old.
ID Summary: Smallish tree with white bark, nearly round leaves with long, flat stems, and 25 to 30 teeth per side, according to Nelson, Earle, and Spellenberg’s Trees of Eastern North America.
Similar Trees: Bigtooth Aspen (Populus grandidentata) has darker bark and leaves with 6 to 15 teeth per side (Nelson, et al.). Quaking and Bigtooth Aspens hybridize, so intermediate forms may be present. The light-colored bark can be distinguished from that of Paper Birch (Betula papyrifera) by Aspin’s powdery surface and the fact that it doesn’t peel.
Quaking Aspen thrives in cooler climates. It does well on poor, rocky soils, and is often the pioneer tree in areas damaged by fire or landslides, until it’s crowded out by other trees. Popple is the most widespread North American tree, and is native as far north as Alaska, and as far south as Mexico, at high altitudes. According to Lucy Braun’s The Woody Plants of Ohio, Quaking Aspen is found in all of Ohio’s northern and eastern counties, but is absent in most of the southwest quadrant. The Columbus, Ohio Street Tree Inventory does not list Quaking Aspen among the 80 most common trees.
Quaking Aspen lumber has a Janka hardness of 350 lbf and a density of 0.42 g/cc, according to the Wood Database, compared to the median of my list of 73 Ohio trees of 1,075 lbf and 0.64 g/cc. Its low strength and density make it a rather poor choice for furniture, but a good choice for paper pulp – especially magazine pages, oriented strand-board, and particle board. Aspen has no odor and imparts no taste to food-stuffs, so it’s perfect for baskets, bowls, ice cream sticks, and tongue depressors. Children’s toys made from aspen remain splinter-free. And like many woods with low commercial value, much of it is made into pallets. As is true of most light-colored woods, Quaking Aspen has low durability (rot-resistance).
Until recently, P. tremuloides was used extensively for wooden matches and for packing material in the form of excelsior (wood shavings). Because Popple grows readily from shoots, it lends itself to coppicing, for use as biofuel, and in the past, animal fodder. Quaking Aspen’s low density and resistance to splitting makes it a poor firewood. It also smokes badly. Rebecca Rupp’s Red Oaks and Black Birches repeats an early poem, “Poplar gives a bitter smoke, fills your eyes and makes you choke”. But while a cord of aspen firewood produces very little heat, its vigorous growth makes it more productive than maple or hickory on an BTU per-acre basis, making it potentially the better bio-fuel.
An interesting comment in the Wood Database noted that aspen does not readily absorb heat, and is therefore used to make seats and surfaces in saunas, allowing one to sit on it naked without getting burned. Several other sources, including the USDA Silvics Manual, associate Quaking Aspen with sauna benches, because the wood does not cause splinters. I hate when that happens.
According to the Native American Ethnobotany Database, Native uses for Quaking Aspen included the following:
- Abnaki – Bark infusion as a vermifuge (for worm removal),
- Algonquin – Poultice of roots for rheumatism,
- Apache – Inner bark made into edible cakes, sap for flavoring wild strawberries,
- Bella Coola – Decoction of root bark for STDs,
- Blackfoot – Bark infusion for heartburn, bark fed to horses, inner bark eaten in the spring,
- Southern Carrier – Bark infusion for stomach distress,
- Cheyenne – Logs used in construction,
- Chippewa – Bark infusion as a gynecological aid,
- Cree – Crushed leaves used as dermatological aid, white powder scraped from outer bark to stop bleeding and to treat STDs, rotted wood smoke for meat preservation,
- Gitksan – Bark decoction to induce vomiting,
- Iroquois – Bark decoction for measles and pleurisy,
- Klamath – Bark used to make hats,
- Micmac – Bark used to treat colds, bark used to stimulate appetite,
- Montana – Bark used for cordage, wood used for fuel,
- Navajo – Wood used to make ceremonial hoops, wood carved into cups,
- Ojibwa – Wood made into paper pulp,
- Okanagan Colville – Outer bark scrapings for anti-perspirant,
- Shuswap – Branches carved into whistles,
- Tanana – Wood ashes mixed with tobacco for chewing,
- Tewa – Decoction of leaves for urinary problems,
- Thompson – Wood ashes rubbed on body to prevent hair growth, decoction of branches drunk to cure “insanity” from excessive alcohol consumption, decoction of branches used as wash to thwart witches, wood used to make dugout canoes.
No doubt, Quaking Aspen’s myriad uses is due in part to its wide distribution.
Quaking Aspen belongs to the willow family (Salicaceae), and contains, especially in the bark, salicylic acid – the primary ingredient of aspirin.
Akiva Silver’s Trees of Power states that, “There are virtually no herbivores that do not feet on poplars, and quaking aspen offers the most food of all the poplars. It grows the most stems with its endless suckering habit”. Silver continues, “Quaking aspens are so tough, they can be cut ruthlessly and repeatedly and show no loss of vigor”.
Wildlife makes extensive use of Quaking Aspen as a food source. Red Oaks and Black Birches indicates that its shoots make up as much as a quarter of the diet of White-Tailed Deer in some areas. It also says that beavers eat the bark, fell the trees with their chewing, and stash their winter supply of twigs in lodges built of Popple branches. Rabbits also favor the shoots of Quaking Aspen.
Many insects feed on aspens, including the Aspen Leaf Beetle, and aphids. Other insects bore through the wood, including the Poplar Twig Borer, the Poplar Branch Borer, the Poplar Borer, and the Flat-Headed Poplar Borer. Butterflies that feed on Quaking Aspen include the Viceroy, the White Admiral, the Mourning Cloak, and the Compton Tortoiseshell.
Various birds eat the catkins, including the Ruffed Grouse, Prairie Chicken, and Purple Finch. Yellow-Bellied Sapsuckers bore into the tree to consume the sap, and some birds consume the insects attracted to Quaking Aspen. The Red-Breasted Nuthatch, Yellow Warbler, Warbling Vireo, and Northern Flicker next in the tree’s branches.
Quaking Aspen is the State Tree of Utah.
Legend has it that aspen was used to make the crucifix upon which Christ was executed. Accordingly, aspen was once a much larger, stronger tree, but was punished for its role, and is so fearful for its fate that it trembles in the presence of the Lord. Dogwood is also often cited as the tree used to make the crucifix. Spike Carlsen’s A Splintered History of Wood also lists pine, olive, palm, olive, cedar, cypress, and mistletoe as trees, or in the case of mistletoe, former trees, used to make the crucifix. Alexander Porteous’ The Forest in Folklore and Mythology adds fig, oak, elder, and ash to the potential list of culprits. Red Oaks and Black Birches tells of another legend, in which Judas Iscariot hanged himself from an aspen, conflicting with the more widely-told version in which he used a Redbud (Cercis canadensis, aka, Judas Tree). In any case, fossil evidence shows that ancient aspen leaves had similar shapes to today’s, and probably trembled millions of years before the crucifiction.
Simon Wills’ A History of Trees relates some Greek mythology in which the sun god, Zeus, was implored by his son, Phaethon, to allow him to drive the chariot that carried the sun across the sky. Zeus relented, but Phaethon lost control of the horses. Afraid that the sun would crash into the earth, Zeus sent a thunderbolt across the sky, causing Phaethon to plunge into the river Po. Phaethon’s sisters wandered the river bank mourning him, and to relieve their grief (or maybe just to silence them), Zeus turned his daughters into poplar trees.
Laura C. Martin’s The Folklore of Trees and Shrubs states that according to the Doctrine of Signatures, from a Swiss physician in the 1600s, plants resemble the human body parts that they were destined to cure. Accordingly, P. tremuloides was used to treat diseases associated with shaking.
According to the Dragon Oak website, “Poplar wands have an incredibly diverse energy, allowing it to be an all-purpose wood for magickal workings. The diversity of the energy in this wood makes it useful for evocation as well as banishment rituals. It is also strong with the elements of hope, rebirth, and divinations”.
Although it’s not common here in Central Ohio, if you travel, you’re sure to encounter this small tree with a huge distribution.
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You can also listen to my talks on Ohio Broadleaf Tree Identification on YouTube, Part 1 and Part 2.
