Wat maakt De Populier uniek? (Mei 2024)
Populier, (geslacht Populus), geslacht van ongeveer 35 soorten bomen in de wilgenfamilie (Salicaceae), afkomstig uit het noordelijk halfrond. De populierensoort afkomstig uit Noord-Amerika is verdeeld in drie losse groepen: de populieren, de espen en de balsempopulieren. De naam Populus verwijst naar het feit dat de bomen in de Romeinse tijd vaak werden geplant rond openbare ontmoetingsplaatsen. Het hout van populieren is relatief zacht en wordt daarom meestal gebruikt voor het maken van kartonnen dozen, kratten, papier en fineer.
Fysieke beschrijving
Populieren zijn snelgroeiende maar relatief kortlevende bomen. Ze zijn wijd verspreid over de noordelijke gematigde streken, van Noord-Amerika tot Eurazië en Noord-Afrika. De bladeren zijn afwisselend en ovaal of hartvormig, met fijn tot grof getande randen (bladranden). De bladeren trillen karakteristiek in de wind, vanwege hun platte bladstelen (bladstelen). In Noord-Amerika hebben espen meestal niet-kleverige toppen en gladde grijs-tot-groene schors, terwijl populieren en populieren met balsem kleverige toppen en bast hebben die donkerder en diep doorgroefd is. Populieren zijn tweehuizige planten, wat betekent dat de mannelijke en vrouwelijke bloemen op afzonderlijke bomen groeien. De bloemen bloeien in hangende katjes (hangende uniseksuele bloemtrossen) voordat de bladeren tevoorschijn komen, om windbestuiving te vergemakkelijken.De vruchten zijn kleine, dikwandige capsules die vele kleine zaadjes bevatten, bekleed met donzige plukjes zijdeachtige haren. De zaden worden vaak in grote hoeveelheden vrijgegeven en de pluizige zaadharen helpen bij het verspreiden van de wind.
Common species
Two well-known poplar species of Eurasia are the white and black poplars. The white poplar (P. alba)—also known as silver poplar for its leaves, which have white felted undersides, and as maple leaf poplar for the leaves’ lobed margins—is widely spreading or columnar in form, reaching 30 metres (100 feet) in height. The gray poplar (P. ×canescens), a close relative of the white poplar, has deltoid (roughly triangular) leaves with woolly grayish undersides. The black poplar, or black cottonwood (P. nigra), has oval fine-toothed leaves, is long-trunked, and grows to a height of 35 metres (115 feet). Columnar black poplars are widely used in ornamental landscape plantings, particularly among the villas of Italy and elsewhere in southern Europe. White and black poplars are widely planted in the eastern United States and in Canada.
The balsam poplar, or tacamahac (P. balsamifera), which is native throughout northern North America in swampy soil, is distinguished by its aromatic resinous buds. The buds of the balm of Gilead poplar (P. ×jackii), which is similar, are used to make an ointment. The western balsam poplar, also called black cottonwood (P. trichocarpa), grows some 60 metres (195 feet) tall and is one of the largest deciduous trees of northwestern North America.
The common European aspen (P. tremula) and the American quaking, or trembling, aspen (P. tremuloides) are similar trees and reach a height of about 27 metres (90 feet). Quaking aspen is distinguished by its leaves, which have more-pointed tips, and spreads by rhizomes (underground stems). Clonal colonies of quaking aspen can grow quite large, and the most massive clonal organism on Earth is believed to be a forest of genetically identical trees, known as Pando, in Utah. The American big-tooth aspen (P. grandidentata) grows up to 18 metres (59 feet) and has larger, somewhat rounded, coarse-toothed leaves.
Cottonwood trees have distinctive deeply fissured bark and are exceptionally tolerant of flooding and erosion. Native to North America, the common, or eastern, cottonwood (P. deltoides) reaches nearly 30 metres (100 feet) tall and bears thick glossy leaves. The Fremont, or Alamo, cottonwood (P. fremontii) is the tallest of the cottonwoods and is found throughout southwestern North America.
Unrelated species
The tulip trees of the genus Liriodendron (family Magnoliaceae) are sometimes referred to as tulip, or yellow, poplars. Known for their showy flowers and distinctive leaves, the genus consists of two species, the Chinese tulip tree (L. chinense), native to China and Vietnam, and the American tulip tree (L. tulipifera), found throughout eastern North America.
