Practical ecological knowledge for the temperate reader.

Populus Sp. - Cottonwood

Family: Salicaceae - Willow Family [E-flora]

"40 species: northern hemisphere. (Latin: name for plants of this genus) [Hamzeh et al. 2006 J Torrey Bot Soc 133:519–527]"[Jepson2012]

Local Species;

Populus Sp.;


"Production: Poplar bark consists of the fresh or dried bark of salicin-rich Poplar species as well as their preparations. Poplar leaves consist of the leaves of salicin-rich Poplar species as well as their preparations. Poplar buds consist of the dried, unopened leaf buds of Populus species, as well as their preparations." [PDR]

Medicinal Uses



Populus balsamifera ssp. trichocarpa

"Populus trichocarpa is a deciduous Tree growing to 40 m (131ft) by 12 m (39ft) at a fast rate.
It is hardy to zone (UK) 5. It is in flower from Apr to May, and the seeds ripen from May to June. The flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required) and are pollinated by Wind.The plant is not self-fertile. [PFAF]
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in heavy clay soil. Suitable pH: acid, neutral and basic (alkaline) soils and can grow in very acid soils.
It cannot grow in the shade. It prefers moist soil." [PFAF]


General: Dioecious tree up to 50 m tall; not colonial; branches brown the first year, turning grey later; twigs smooth or sparsely hairy. [IFBC-E-flora]
Leaves: Alternate, deciduous, simple, narrowly to broadly egg-shaped or lanceolate, 5-20 cm long, 3-12 cm wide, the bases tapered to heart-shaped or squared-off smooth, finely toothed and hairy on the margins, the teeth often tipped with a callous gland, lower side whitish or pale green and brownish; leaf stalks 2-10 cm long, often with a pair of glands near the blade; buds finely hairy with fringed scales. [IFBC-E-flora]
Flowers: Borne in catkins; male catkins 2-3 (5) cm long, soon deciduous, with 8-60 stamens; female catkins 8-20 cm long. [IFBC-E-flora]
Fruits: Capsules, broadly egg-shaped, carpels 2-3, smooth or hairy, nearly unstalked. [IFBC-E-flora]
Two subspecies occur in BC. The hybrids P. angustifolia James x P. balsamifera ssp. trichocarpa (P. x brayshawii Boivin) and P. balsamifera ssp. trichocarpa x P. nigra L. var. italica DuRoi are rare in BC .
1. Ovaries and capsules smooth; leaves pale green and brownish beneath.................... ssp. balsamifera
1. Ovaries and young capsules hairy; leaves whitish beneath.................... ssp. trichocarp (T. & G.) Brayshaw [IFBC-E-flora]

USDA Flower Colour: Yellow
USDA Blooming Period: Mid-Spring
USDA Fruit/Seed characteristics:

Colour: White
Present over the Spring [USDA-E-flora]

Habitat / Range

Moist uplands and floodplains in the montane zone; ssp. balsamifera - common in N and E BC; ssp. trichocarpa - common throughout BC except rare on Queen Charlotte Islands; ssp. balsamifera - N to YT, AK and NT, E to NF and S to NY, VA, IL, IA, CO, ID and OR; ssp. trichocarpa - N to S AK and YT, E to SW AB and S to ND, WY, UT, NV and CA. [IFBC-E-flora]

Origin Status: Native [E-flora]

Edible Uses

Other Uses



"A very easily grown plant, it does well in a heavy cold damp soil[1]. Prefers a deep rich well-drained circumneutral soil, growing best in the south and east of Britain[11, 200]. Growth is much less on wet soils, on poor acid soils and on thin dry soils[11] but this species is more tolerant of acid soils than other members of the genus[11]. It dislikes shade and is intolerant of root or branch competition[11, 200]. Plants are reasonably wind resistant, but they do not grow well in exposed upland sites[11]. Many forms of this species are susceptible to bacterial canker, the female clone 'Fritzi Pauley' is resistant[11, 200]. A very fast growing[11] and ornamental tree[1], it does well in western Britain where trees have reached 25 metres tall in 20 years[11]. The leaf buds, as they swell in the spring, and the young leaves have a pleasing fragrance of balsam[245]. The fragrance is especially pronounced as the leaves unfold[245]. Poplars have very extensive and aggressive root systems that can invade and damage drainage systems. Especially when grown on clay soils, they should not be planted within 12 metres of buildings since the root system can damage the building's foundations by drying out the soil[11]. Dioecious. Male and female plants must be grown if seed is required." [PFAF]

Wildlife: Populus catkins, buds, leaves, and shoots are browse for moose and rabbits. American Medicinal Plants notes that quaking aspen shoots and leaves are gathered in Sweden and fed to domestic sheep in winter. Trappers often use quaking aspen as bait in beaver sets. Bees chew the resins of poplar and other trees, mix them with their enzymes, and regurgitate as bee glue. [Schofield]

"Seed - must be sown as soon as it is ripe in spring[113]. Poplar seed has an extremely short period of viability and needs to be sown within a few days of ripening[200]. Surface sow or just lightly cover the seed in trays in a cold frame. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the old frame. If sufficient growth is made, it might be possible to plant them out in late summer into their permanent positions, otherwise keep them in the cold frame until the following late spring and then plant them out. Most poplar species hybridize freely with each other, so the seed may not come true unless it is collected from the wild in areas with no other poplar species growing[11]. Cuttings of mature wood of the current season's growth, 20 - 40cm long, November/December in a sheltered outdoor bed or direct into their permanent positions. Very easy. Suckers in early spring[78]." [PFAF]


Trembling Aspen - Populus tremuloides

"Populus tremuloides is a deciduous Tree growing to 20 m (65ft) by 10 m (32ft) at a fast rate." [PFAF]

Origin Status: Native [E-flora]


Food Use:

Other Uses

Medicinal Use:

"Powdered bark. Dose, one dram two or three times a day. Saturated tincture of the bark, from one-half to twenty drops. Populin, one-tenth of a grain." [Ellingwood]

"Therapy—The older writers were enthusiastic concerning the tonic and antiperiodic properties of this drug. They claimed that it would replace quinine in the treatment of intermittency. It has never come into general use. A recent writer says that he soon learned that a strong infusion of the bark would cure those forms of intermittent fever, of a chronic or irregular character. At the same time the pathological lesions of the liver, spleen and kidneys which accompanied the chronic disorder, would gradually disappear with the ultimate complete restoration of their physiological functions. These results were accomplished without the unpleasant effects that occur after the protracted use of quinine. This writer, passing through an epidemic of severe malarial disease, found that malarial hematuria was very common and very hard to cure. He put his patients upon the infusion of cottonwood bark, and found the symptoms to yield rapidly, not only the hemorrhage, but the icterus, and other conditions depending upon disarrangement of the liver and stomach. He found that results obtained by this remedy were more permanent than those obtained by the use of quinine in some cases.
Protracted fevers, with debility and emaciation, are greatly benefited by the use of this remedy, and the conditions remaining in early convalescence are quickly overcome. The agent is a tonic to the kidneys, increasing their functional activity, relieving vesical and urethral tenesmus. it will also overcome prostatic hypertrophy in some cases, and is available in uterine congestion. It is of service in impaired digestion, either gastric or intestinal, chronic diarrhoea, with general debility. Other specific remedies may here be given in conjunction with it. Dr. Alter says that it corrects errors of physiological metabolism, induced by malarial toxemia. It is a most powerful antiperiodic. It will not cause deafness. It will not cause abortion, but on the contrary will prevent abortion, which is threatened by the presence of malarial conditions. It shows its influence best where there is general debility, very marked, with impairment of the nutritive functions of the body." [Ellingwood]

"Dr. Fearn says, concerning populus, this remedy is a powerful stimulant, tonic, and diuretic. And this statement fixes its place in treatment, in the hands of the true specific medicationist. When we use this remedy as a tonic or diuretic, we should never use it in cases accompanied with irritation whether it be of the stomach, bowels, uterus, bladder, or prostate. In atonic conditions of all these different organs where we desire to stimulate and tone up the organ, populus is a grand remedy. When first I began to use this Sampson among remedies of its class, I had to use decoctions of the bark—it was a nasty, bitter dose. How much better to use the specific medicine in from five to twenty drop doses. Dr. Howe reported a case where a soldier had chronic diarrhea which may have been caused by malaria. Howe put him on populus for a time and made a complete cure. If a little of the poplar bark be put into a cup and covered with boiling water, this will make a strong enough infusion for many conditions, taking only a teaspoonful or two at a time." [Ellingwood]

"Dr. Alter of Arkansas has given it for many years for swamp fever. He also uses it in the irregularities of women. He thinks it acts somewhat as hydrastis in promoting a physiological action of all organs, and increasing the vital force within the system. It may be well given in conjunction with hydrastis. Dr. Alter used it very widely whether it was strictly indicated or not, and became convinced of its active therapeutic property." [Ellingwood]

"The Forest Potawatomi sometimes use the Ojibwe name for this “asa'dis” [rabbit food]. The Prairie Potawatomi call it “mîtwi”. The Forest Potawatomi burn the bark of the Quaking Aspen and save the ashes to mix with lard which forms a salve to apply to sores upon horses. Among the whites282 the bark is valued for its tonic, stomachic, febrifuge and aperient properties. Another authority283 records the use of the bark and leaves in acute rheumatism, to lower the temperature in fevers, to relieve pain and to reduce arterial swellings, to treat coryza, hay-fever, influenza, neuralgia and diabetes. Among eclectic practitioners, it has been used externally as a wash for gangrenous wounds, eczema, cancer, burns, fetid perspiration and as a wash. When it is used as a wash, borax is added to the bark extract." [HuronSmith Zuni]



Cultivation and Propagation

"A fast-growing tree, it rapidly invades bare areas such as logged woodland and soon establishes dense stands of young trees by sending up suckers[226, 229]. It provides excellent conditions for other species of trees to become established and these will eventually out-compete the poplar[229].
… Unlike most members of the genus, this species is drought tolerant once it is established[226]. It is fairly wind tolerant, though it does not do well in exposed upland sites[11]. It dislikes shade and is intolerant of root or branch competition[200]. A fast-growing species that is quite short-lived, though occasional specimens live to almost 200 years[229]. Poplars have very extensive and aggressive root systems that can invade and damage drainage systems. Especially when grown on clay soils, they should not be planted within 12 metres of buildings since the root system can damage the building's foundations by drying out the soil[11]. Dioecious. Male and female plants must be grown if seed is required."[PFAF]

"Seed - must be sown as soon as it is ripe in spring[113]. Poplar seed has an extremely short period of viability and needs to be sown within a few days of ripening[200]. ... This species is rather difficult from cuttings[11, 113]. Suckers in early spring[78]. Root cuttings in the winter[200]. Layering[200]."[PFAF]

Mycological Associations
"Parasitic mushrooms found on the living tree are Armellaria mellia, Pholiota squarrosoides and P. squarrosa. The delectable oyster mushroom, Pleurotus is often found on dead aspen. A symbiotic associate of aspen is the interesting and poisonous hallucinogenic Amanita musscaria. The sweetened broth of this fungus is a potent fly-killer. The root-like structure of A. muscaria and the terminal rootlets of aspen together form a joint structure called a mvchorrhiza. The fungus derives some of its nutrition from the structure, but what the tree derives from it is not clearly understood. Young aspen will die in the absence of this fungus." [Northern Bushcraft]


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