Nearly 6 years ago I have written part 1 of the Salicaceae or the Willow and Poplar family. See https://wonderfulweedweekly.co.uk/the-salicaceae-or-willow-family
That was all about the different species of willows found in the British Isles and their uses.
This time I will complete the family with all the Poplars known. They aren’t easy to identify except for the Aspen and White Poplar perhaps.
I found a wonderful website/identification guide from ‘The Flora of East Anglia‘ on the identification of many typical poplars and their cultivars.
Contents:
11 species, several ssp and many more cultivars are given in Stace and 5 different Poplars are included in ‘The Medicinal Flora of Britain and Northwestern Europe’ by J. Barker.
Many thanks for the information for Poplars by the Plant Atlas Online. The link below the Scientific Names brings you to their website. Thanks fore pictures by Mike Poulton, Dave Cadman, Matt Summers and Wikipedia (which is also often used for more information about the individual plant).
FBBC is added behind the name in the contents when it also grows in the Birmingham and Black Country area as mentioned in the Flora!
The genus Populus and how to identify them
Ornamental, Food/Fodder and Other uses
P. nigra subsp. betulifolia or Black-poplar FBBC
P. tremula or Aspen FBBC
P. alba or White Poplar (Neophyte) FBBC
P. × canescens (P. alba × tremula) or Grey Poplar (A cultivated hybrid (native × alien)) FBBC
P. balsamifera or Eastern Balsam-poplar (Neophyte) FBBC
P. trichocarpa or Western Balsam-poplar (Neophyte) FBBC
P. nigra or Lombardy Poplar (fastigate cultivars) (Neophyte) FBBC
P. × jackii (P. balsamifera × deltoides) or Balm-of-Gilead (A cultivated hybrid (alien × alien)) FBBC
P. × hastata (Populus balsamifera × trichocarpa) or Hybrid Balsam-poplar (A cultivated hybrid (alien × alien)) also former P. ‘Balsam Spire’ FBBC
P. × canadensis (P. deltoides × nigra) or Hybrid Black-poplar (A cultivated hybrid (native × alien)) FBBC
P. × generosa (P. deltoides × trichocarpa)or Generous Poplar (A cultivated hybrid (alien × alien)
P. × berolinensis (P. nigra ‘Italica’ × laurifolia) or Berlin Poplar (A cultivated hybrid (native × alien).
The genus Populus
Populus is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar, aspen and cottonwood.
How to identify the Poplars (by Stace)
The most important characters are the general habit of the tree and the shape of leaves on the dwarf lateral shoots and not the leaves of the suckers or epicormic shoots, as these are very different! The sex of the tree can be important in identification.
The flowers are mostly dioecious (male and female on separate trees) and appear in early spring before the leaves. They are borne in long, drooping, sessile or pedunculate catkins produced from buds formed in the axils of the leaves from the previous year.
Apart from the need for mature leaves, most characters are best observed in late spring, when shoot hairiness and colour, sex and tree-shape are all obvious.
Note that male plants largely dominate in the landscape because female plants produce enormous amounts of wind-blown, fluffy seeds that are not popular with some people!
Different Uses of the Poplars:
Many poplars are grown as ornamental trees, with numerous cultivars used. They have the advantage of growing to a very large size at a rapid pace. Trees with fastigiate (erect, columnar) branching are particularly popular, and are widely grown across Europe and southwest Asia.
However, like the willows, poplars have very vigorous and invasive root systems stretching up to 40 metres (130 ft) from the trees; planting close to houses or ceramic water pipes may result in damaged foundations and cracked walls and pipes due to their search for moisture.
In addition to the foliage and other parts of Populus species being consumed by animals, the starchy sap layer (underneath the outer bark) is edible to humans, both raw and cooked.
- In many areas, fast-growing hybrid poplars are grown on plantations for pulpwood
- Poplar is widely used for the manufacture of paper.
- It is also sold as inexpensive hardwood timber, used for pallets and cheap plywood; more specialised uses including matches and matchboxes and the boxes for Camembert cheese.
- Poplar wood is also widely used in the snowboard industry for the snowboard core, because it has exceptional flexibility, and is sometimes used in the bodies of electric guitars and drums.
- Poplar wood, particularly when seasoned, makes a good hearth for a bow drill.
- Due to its high tannic acid content, the bark has been used in Europe for tanning leather.
- Poplar wood can be used to produce chopsticks or wooden shoes.
- Baking moulds from peeled poplar may be used in the freezer, oven, or microwave oven.
Below are the Poplars found in the Plant Atlas Online. Only the first 2 are native:
P. nigra subsp. betulifolia or Black-poplar and see here
A majestic, spreading, broad-crowned tree, with a burred trunk. It is generally found as a field-tree, often beside watercourses and by ponds and also in hedgerows, especially on lowland floodplains. It is sometimes planted as part of biodiversity enhancement schemes and as an amenity tree in urban areas. Most planted specimens are males and are propagated clonally.
Male Black Poplars have red catkins in Spring, known in some parts as “Devil’s fingers”, whereas the female flowers are yellow-green. They’re wind pollinated, but foodplants to several moths.
The trees were much prized in the 17th and 18th centuries for their wood, which is fire resistant and was used around fireplaces. Its open grain meant it could absorb paraffin wax and so its was used for matches, while its springiness and tendency not to splinter also meant Black Poplar wood was used for cartmaking.
Black poplar is the food plant for the caterpillars of many moths, including the hornet, wood leopard, poplar hawk and figure of eight. The catkins provide an early source of pollen and nectar for bees and other insects, and the seeds are eaten by birds.
Only around 7,000 wild black poplars now grow in Britain and of these, only 600 are female trees!
Upper respiratory tract infections, cystitis, gout, rheumatic pain. Externally for cuts, haemorrhoids, anal fissure and joint pain.
P. tremula or (Quaking) Aspen and see here
A broad-crowned tree of moist clay or sandy soils found in mixed broad-leaved woodlands, hedgerows, on heathland, in disused clay- and sand-pits, and occasionally in pinewoods. In northern and western Britain, it grows on cliffs, rocky outcrops and riverbanks, as a possibly ancient dwarfed tree or shrub in exposed situations or on poor soils. It suckers to form thickets, and readily colonizes bare ground.
The aspen is found in cultivation in parks and large gardens. The fastigiate cultivar ‘Erecta’, with bright yellow autumn colouring, has gained the Royal Horticultural Society‘s Award of Garden Merit.
The wood of aspen is light and soft with very little shrinkage.
It is used for lumber and matches but is also valued in the pulp and paper industry, being particularly useful for writing paper. In addition, it is used for plywood and different types of flake and particle boards. Given its hardiness and capacity for rapid growth and regeneration, it plays an important role in the production of wood for renewable energy. Ecologically, the species is important as many insect and fungi species benefit from it. The tree further provides habitat for several mammals and birds that require young forests.
For fever, cystitis, benign prostatic hypertrophy and rheumatism.
P. alba or White Poplar (Neophyte) and see here
A robust tree, typically reaching up to 20 m in height, with a broad, spreading crown, frequently planted for amenity purposes in parks and along roadsides, and also as a windbreak in coastal areas due to its resistance to salt-laden winds; it is rarely used in forestry. It spreads vigorously by suckering, but rather rarely reproducing by seed as most trees in our area are female and male trees are very rare.
White poplar hybridizes with the closely related common aspen Populus tremula; the resulting hybrid, known as grey poplar (Populus × canescens), is intermediate between its parents, with a thin, grey, downy coating on the leaves, which are also much less deeply lobed than white poplar leaves. It exhibits marked hybrid vigour, reaching 40 m (130 ft) tall and a trunk diameter over 1.5 m (4 ft 11 in), much larger than either of its parents. Most grey poplars in cultivation are male, but female trees occur naturally and some of these are also propagated.
The bark is febrifuge.
The wood is soft but close-grained and easy to carve, shrinking very little during seasoning. It has been used for sculpture from Europe to China and the US. The Penitent Magdalene by Donatello is one 15th-century example.
It was the most commonly used wood for panel paintings in Italy throughout the Middle Ages and Renaissance, until mostly replaced as a matrix by canvas from 1500 onwards. Most earlier Italian Renaissance paintings are painted on poplar panels, the Mona Lisa being but one example.
White poplar requires abundant light and ample moisture, and stands up well to flood water and slightly acidic soils. Its green-and-white leaves make it an effective ornamental tree, but the root suckers may cause problems in some situations. It is very attractive as an open-grown tree in water meadows, and because of its extensive root system and tolerance of salt, is also planted to strengthen coastal sand dunes.
A yellow dye is produced from the bark of the white poplar.
The majority of white poplars in cultivation in northern Europe are female trees.
Leaves from P. × canescens (P. alba × tremula) or Grey Poplar (by Mike Poulton)
P. × canescens (P. alba × tremula) or Grey Poplar (A cultivated hybrid (native × alien)) and see here
This broad-crowned tree often grows as a solitary, usually male, specimen or among native trees and shrubs. It is planted in windbreaks and as an amenity tree, especially in damp woods and by streams. Plants sucker freely even if undamaged but with particular vigour after felling or natural damage. Thickets sometimes develop, and large stands may be found in damp woods.
Although no specific mention has been seen for this species, the bark of most, if not all members of the genus contain salicin, a glycoside that probably decomposes into salicylic acid (aspirin) in the body. The bark is therefore anodyne, anti-inflammatory and febrifuge. It is used especially in treating rheumatism and fevers, and also to relieve the pain of menstrual cramps.
P. balsamifera or Eastern Balsam-poplar (Neophyte)
An attractive deciduous tree growing up to 35 m in height, widely planted in hedgerows, amenity areas and on roadsides, and in small quantities for timber. It reproduces vigorously by suckering.
The tree is known for its strong, sweet fragrance, which emanates from its sticky, resinous buds. The smell has been compared to that of the balsam fir tree.
The light, soft wood of Populus balsamifera is used for pulp and construction. The resinous sap (or the tree’s balsam) comes from its buds, and is sometimes used as a hive disinfectant by bees.
Branches containing the resinous buds are sometimes blown to the ground by spring windstorms, and herbalists from many cultures seek these out to make medicine from them. These sticky spring buds are a highly prized ingredient in medicinal salves and other herbal preparations in both Indigenous North American and European herbal traditions.
Many kinds of animals use the twigs of Populus balsamifera for food. The leaves of the tree serve as food for caterpillars of various Lepidoptera.
P. trichocarpa or Western Balsam-poplar (Neophyte) and here
A graceful, narrowly upright deciduous tree with spreading lower branches, widely planted as an ornamental in parks, gardens and on roadsides, and less frequently in shelter-belts and for timber. Our specimens differ from those of its native range in having longer, proportionately narrower leaves. Most planted trees are male and these cannot reproduce, but they occasionally spread by suckers. The seed will only germinate within a day or two of being shed and self-sown trees have been reported from Cambridgeshire.
Traditional Uses by native American tribes:
The tree was and is significant for many Native American tribes of the Western United States. Some Native Americans consumed cottonwood inner bark and sap, feeding their horses the inner bark and foliage. The wood, roots and bark have been used for firewood, canoe making, rope, fish traps, baskets and structures. The gum-like sap was used as a glue or as waterproofing. The Quinault used it for post wood. The Cowlitz made the base (hearth board) of their fire-making tool, a bow drill, with its wood. The Squaxin cut young branches for building sweat lodges.
The Squaxin used the bark for sore throats and for the treatment of tuberculosis, as well as water and the bruised leaves as an antiseptic mixture. The Klallam used the buds for an eye treatment. For the Quinault, they extracted gum from the burls and applied it to cuts on the skin.
Commercial extracts are produced from the fragrant buds for use as a perfume in cosmetics.
P. trichocarpa wood is light-weight and although not particularly strong, is strong for its weight. The wood material has short, fine cellulose fibres that are used in pulp for high-quality book and magazine paper. The wood is also excellent for production of plywood. Living trees are used as windbreaks.
This species grows very quickly; trees in plantations in Great Britain have reached 18 m (59 ft) tall in 11 years, and 34 m (112 ft) tall in 28 years. It can reach suitable size for pulp production in 10–15 years and about 25 years for timber production.
P. nigra or Lombardy Poplar (fastigate cultivars) (Neophyte) and see identification guide from here
The fastigate cultivars of P. nigra are deciduous trees with narrow crowns, growing up to 38 m in height, that are widely planted for amenity in parks, gardens and on roadsides, but also in screens, shelter-belts and windbreaks in rural areas. Although conspicuous as landscape features, these cultivars are all single-sex clones and are almost always planted.
A number of fastigiate cultivars are widely planted, including the narrowly fastigiate male ‘Italica’, the slightly broader male ‘Plantierensis’ which is increasingly planted, and the much broader female ‘Gigantea’. ‘Italica’, the true Lombardy-poplar, originated in northern Italy and was recorded in the wild by 1886.
The bark is febrifuge.
P. × jackii (P. balsamifera × deltoides) or Balm-of-Gilead (A cultivated hybrid (alien × alien))
A deciduous tree which is most frequently planted in damp woods and by rivers and ponds, but is increasingly being planted in parks and along roadsides. Only female plants are known in our area but they often become naturalized by suckering.
The variegated cultivar ‘Aurora’ is widely planted as an ornamental. See here
This cultivar has become less popular over time as this hybrid is very prone to a canker that disfigures and often eventually kills the tree. See here.
The tree is named after the unrelated biblical Balm of Gilead, a Commiphora resin. Its leaf buds are coated with a resinous sap with a strong, pleasant turpentine or balsam odour that is most evident as the leaves unfold in the spring. For purposes of commerce, the buds are collected before they open, and can be cut up for pot-pourri or used in herbal medicine.
Like other poplars, balm-of-Gilead is expected to contain salicin in its bark, and in relation to traditional herbal treatment have been regarded as antiscorbutic , antiseptic , balsamic, diuretic, expectorant, stimulant and tonic.
According to the Medicinal Flora by J. Barker:
For acute and chronic laryngitis. Loss of voice. Useful for children’s upper respiratory complaints. As a gargle for sore throats. As an ointment in myalgia and arthralgia.
Despite the tree’s fragrance, the wood is “soft, rather woolly in texture”, and lacks odour or taste, and is of relatively low flammability. A rooting hormone has been collected by soaking its chopped up shoots in water for a day.
P. × hastata (Populus balsamifera × trichocarpa) or Hybrid Balsam-poplar (A cultivated hybrid (alien × alien)) also former P. ‘Balsam Spire’
A fastigiate, deciduous tree which is widely planted in landscaped parks and amenity areas as screens or windbreaks, and as a timber tree in plantations. It does not sucker.
This female hybrid, raised in North America before being imported by the Forestry Commission in 1948, was released for private planting in 1957. It has become one of the most planted poplars in recent times, being resistant to Marssonina leaf fungi and Melampsora leaf rusts which cause premature leaf withering and reduced growth rates.
See above for P. balsamifera, P. x jackii and P. x hastata.
P. × canadensis (P. deltoides × nigra) or Hybrid Black-poplar (A cultivated hybrid (native × alien)) and see from here.
A broad-crowned tree, frequently planted throughout lowland Britain and Ireland as amenity trees in parkland, along roadsides, railways, riversides, streamsides and canals, in hedgerows, as screens and shelter-belts and as timber trees in plantations, especially on most soils. Of the four most frequently planted clones (‘Serotina’, ‘Robusta’, ‘Regenerata’, ‘Marilandica’), ‘Serotina’ is the oldest and most widely planted.
The hybrid is a frequent host of Viscum album, especially where it has been planted as a shelter-belt around orchards.
See above for P. nigra and subsp. + cultivars.
P. × generosa (P. deltoides × trichocarpa) or Generous Poplar (A cultivated hybrid (alien × alien)).
A vigorous non-suckering tree which is found planted along roadsides and in parks, and increasingly as cultivars in plantations.
This was the first artificially bred hybrid between a Balsam-poplar and a Black-poplar, raised at Kew in 1912. The initial hybrids were very widely planted at first because of their vigorous growth, but after a few decades it became apparent that they were susceptible to bacterial canker, and infected trees often presented a source of infection to other poplars (Jobling, 1990). New, resistant cultivars, such as ‘Beaupré’, are now being increasingly planted for timber production.
P. × berolinensis (P. nigra ‘Italica’ × laurifolia) or Berlin Poplar (A cultivated hybrid (native × alien)).
A fastigiate, deciduous tree mostly grown along roadsides and for screening, and rarely in plantations. It does not sucker.
This hybrid was introduced into cultivation in Britain in 1889 as a male clone from France; our plants are not derived from the original female clone produced in Berlin in 1865. The French clone was widely planted for amenity from the 1930s onwards, but it was not formally recorded from the wild until 1994 (Brent Reservoir, Middlesex). It has been little planted since the 1950s, because it is susceptible to foliar diseases and faster-growing, disease-resistant alternatives have become available.
See above for P. nigra and subsp. + cultivars.