Canadian Poplar

Canadian Poplar

There are about 35 species of fast-growing, deciduous trees in this genus, which occurs throughout northern temperate regions. Poplars grow in a wide range of situations, tolerating wet soils, coastal conditions, and urban pollution; they make excellent screens, avenues, and windbreaks. They new leaves of some species are scented in spring, and many have ornamental variants. Poplars are closely related to willows (Salix species, see, White Willow) and similarly contain salicin, which reduces inflammation and relieves pain. Salicylates provided the basis for aspirin, which was synthesized in the 19th century. Many poplars are very similar in chemistry and are used interchangeably for medicinal purposes. Poplar bark comes mainly from P. alba, but P. nigra (Black Poplar), P. tremuloides (American Aspen), and other species are also used. Populus alba was listed in the U.S. Pharmacopoeia (1895-1936) as a remedy for fevers and menstrual pain. Poplar buds are collected mainly from P. x. candicans, but other sources include P. balsamifera (balsam poplar), and P. nigra. Poplar buds were listed in the U.S. Pharmacopoeia (1916-1965) as an expectorant and stimulant. The sticky bud resin is similarly to propolis, the resinous substance used by bees for sealing honeycombs and gaps in the hive, which has known antibiotic properties. Populus x candicans is often confused with other plants known as "balm of Gilead", such as Abies balsamea (See, Balsam Fir) and Cedronella canariensis (See, Canary Balm). Populus may be derived from the arbor populi, "the people's tree", since poplars have long been planted along town streets.

Fast-growing, conical tree with shiny buds and heart-shaped leaves, to 15cm (6in) long, which are balsam-scented when young. Male trees are not known; females produce catkins, 3-5cm (1¼-2in) logn, reaching 16cm (6in) long when in fruit.

Common Name:	Canadian Poplar
Other Names:	Balm of Gilead, Ontario Poplar
Botanical Name:	Populus x candicans syn. P. x gileadensis, P. x jackii (P. balsamifera x P. deltoides)
Genus:	Populus
Family:	Salicaceae
Location:	N America
Cultivation:	Deep, moist, well-drained soil in sun. Poplars have extensive root systems and should not be planted close to buildings or drainage systems. Prone to bacterial canker and fungal diseases. Aphids, poplar beetle larvae, and caterpillars may attack leaves. Populus alba tolerates drier conditions than most poplars. Prune P. x candicans 'Aurora' hard in late winter to encourage vigourous shoots and colorful new leaves.
Propagation:	By hardwood cuttings in winter; by removing suckers in autumn or winter.
Harvest:	Buds are collected in spring before opening (P. x candicans), and dried for infusions, liquid extracts, and tincture. Bark is stripped from side branches or coppiced trees, and used dried for decoctions, liquid extracts, and powders.
Height:	15-25m (50-80ft)
Width:	6m (20ft)
Variations:	Aurora Has conspicuous new leaves, irregularly variegated creamy-white, and often pink-flushed, which age to green
Hardiness:	Z3-8
Parts Used:	Leaf Buds
Properties:	An antiseptic, anti-inflammatory, expectorant herb that lowers fever, stimulates the circulation, and has antibacterial and antifungal effects. Applied topically, it relieves pain and improves blood flow to the area.
Medicinal Uses:	Internally for bronchitis and upper respiratory tract infections. Externally for colds, sinusitis, arthritis, rheumatism, muscular pain, psoriasis, and dry skin conditions. Widely used in cough mixtures, often with Pinus strobus (See, Scots Pine) and Prunus serotina (See, Wild Black Cherry).
Economic Uses:	Dried buds are added to potpourris
Warning:	Not given to patients allergic to aspirin. Not prescribed to nursing mothers.
Bibliography:	Encylopedia of Herbs by Deni Brown Copyright ©: 1995, 2001 Dorling Kindersley Limited pp.327-328