Populus alba

Populus alba, commonly called silver poplar,[2][3] silverleaf poplar,[2][3] or white poplar,[2][3] is a species of poplar, most closely related to the aspens (Populus sect. Populus). It is native to Morocco and then Spain through central Europe (north to Germany and Poland) to central Asia. It grows in moist sites, often by watersides, in regions with hot summers and cold to mild winters.[4][5]

White poplar
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Malpighiales
Family: Salicaceae
Genus: Populus
Section: Populus sect. Populus
Species:
P. alba
Binomial name
Populus alba
Native range
Synonyms[1]
  • Populus bolleana Lauche
  • Populus major Mill.
  • Populus nivea Wesm.
  • Populus nivea Willd.
  • Populus pseudonivea Grossh.

Description

It is a medium-sized deciduous tree, growing to heights of up to 15–30 m (49–98 ft) (rarely more), with a trunk up to 2 m (6.6 ft) in diameter and a broad, rounded crown. The bark is smooth and greenish-white to greyish-white with characteristic diamond-shaped dark marks on young trees, becoming blackish and fissured at the base of old trees. The young shoots are covered with whitish-grey down, including the small buds. The leaves are 4–15 cm (1 12–6 in) long, five-lobed, with a thick covering of white scurfy down on both sides, but thicker underneath; this layer wears off 8 cm (3 14 in) long, produced in early spring; they are dioecious, with male and female catkins on separate trees; the male catkins are grey with conspicuous dark red stamens, the female catkins are greyish-green. The female catkins lengthen to 8–10 cm (3 14–4 in) after pollination, with several green seed capsules, maturing in late spring to early summer. It also propagates by means of root suckers growing from the lateral roots, often as far as 20–30 m (65–100 ft) from the trunk, to form extensive clonal colonies.[5][6]

Distinguishing features of the white poplar
Foliage of the white poplar
White poplar leaves; underside left, upper side right
Trunk, showing the characteristic diamond-shaped marks

Hybridization

Alley of grey poplars

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 is a very vigorous tree with 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.[5]

Cultivation and uses

Populus alba Pyramidalis

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.[7]

The majority of white poplars in cultivation in northern Europe are female trees.[6]

White poplar was first introduced to North America in 1748 and has a long history in cultivation. It is now found in 43 states throughout the contiguous U.S.[8] It has come to be considered weedy or invasive; it has been banned in Connecticut and is the most common introduced tree species on Cape Breton Island.[9][10][11][12]

In US intensive forest management, it is being replaced by various Populus sect. Aigeiros hybrids. The wood is soft, and used for cellulose and to make cheap boxes.

It also grows in the temperate zones of South America. Mainly in Chile, Argentina and Uruguay

A conical cultivar from Turkestan, Populus alba 'Pyramidalis' (Bolle's poplar; syn. P. bolleana) is sometimes planted in parks.[5]

A yellow dye is produced from the bark of the white poplar.[13]

Sculpture

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.[14] The Penitent Magdalene by Donatello is one 15th-century example.

History

An Old English name abele, now never used, is derived from the Latin albellus, white, by way of Old French aubel and Low German name abeel.[7]

Leuce/Leuka, the "White Poplar"; Leuce or Leuka (Ancient Greek: Λεύκη) ("White" or specifically "White Poplar") was the most beautiful of the nymphs and an Oceanid, a daughter of Oceanus. Pluto fell in love with her and abducted her to the underworld. She lived out the span of her life in his realm, and when she died, the god sought consolation by creating a suitable memorial of their love: In the Elysian Fields, where the pious spend their afterlives, he brought forth a white tree into existence from her body, which became sacred for him from that moment on. In Ancient Greco-Roman mythology, it is a symbol of a peaceful afterlife and a memory of those we love who have died, and in the language of flowers, its meaning is "time". Herakles crowned himself with this tree to celebrate his return from the underworld.

According to ancient Roman mythology, the white poplar was consecrated to Hercules because he destroyed Cacus in a cavern adjoining the Aventine Hill, which was covered with these trees; in the moment of his triumph, he bound his brows with a branch of white poplar as a token of his victory. Persons offering sacrifices to Hercules were always crowned with branches of this tree, and all who had gloriously conquered their enemies in battle wore garlands of it, in imitation of Hercules. Homer in Iliad compares the fall of Simoisius when killed by Ajax to that of a poplar.

So falls a poplar that on watery ground
Raised high its head with stately branches crowned.

Ovid mentions that Paris had carved the name of Ænone on a poplar, as Shakespeare has Orlando carve the name of Rosalind upon the trees of the forest of Arden.

Virgil gives directions for the culture of this tree and Horace speaks of the white poplar as delighting to grow on the banks of rivers.[9]

Invasive potential

The white poplar is an invasive species in many parts of Australia. In Western Australia, it has formed dense stands in disturbed wetlands from Perth to Albany and it is considered a threat to riparian vegetation in Victoria. It has spread along the Murrumbidgee River and in wet areas in rural parts of the Australian Capital Territory.[15] Despite that, it is still sold in nurseries around Australia.[16] White poplar is also an environmental weed in South Africa.[15]

References

  1. The Plant List: A Working List of All Plant Species, retrieved 11 May 2016
  2. "Populus alba". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA).
  3. Webb, C. J.; Sykes, W. R.; Garnock-Jones, P. J. 1988: Flora of New Zealand. Vol. IV. Naturalised Pteridophytes, Gymnosperms, Dicotyledons. 4. Christchurch, New Zealand, Botany Division, D.S.I.R.
  4. Flora Europaea: Populus alba
  5. Rushforth, K. (1999). Trees of Britain and Europe. Collins ISBN 0-00-220013-9.
  6. Flora of NW Europe: Populus alba Archived 2010-08-27 at the Wayback Machine
  7. Vedel, H., & Lange, J. (1960). Trees and Bushes in Wood and Hedgerow. Metheun & Co. Ltd., London.
  8. "PCA Alien Plant Working Group – White Poplar (Populus alba)". Nps.gov. 2009-07-07. Retrieved 2011-07-16.
  9. Keeler, H. L. (1900). Our Native Trees and How to Identify Them pp. 428–432. Charles Scribner's Sons, New York
  10. "PLANTS Profile for Populus alba (white poplar) | USDA PLANTS". Plants.usda.gov. 1999-10-19. Retrieved 2011-07-16.
  11. "white poplar, Populus alba (Salicales: Salicaceae)". Invasive.org. 2010-05-04. Retrieved 2011-07-16.
  12. US invasive state location map
  13. Polunin, O. (1969). Flowers of Europe - A Field Guide. Oxford University Press. ISBN 0192176218., s.v. Populus alba
  14. Ršsch, Petra, Chinese Wood Sculptures of the 11th to 13th centuries: Images of Water-moon Guanyin in Northern Chinese Temples and Western Collections, pp. 179-180, 2007, Columbia University Press, ISBN 3-8382-5662-X, 9783838256627;
  15. "White Poplar". Weedy Connection. Retrieved 2015-10-18.
  16. "Poplar Tree Listing". Small Tree Farm. Retrieved 2015-10-18.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.