Poplar
2 of the 6 encyclopedias on this shelf carry an entry for Poplar. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a genus of Salicacex. Catjagged; disk cup-shaped, oblique, entire. drooping , their scales usually Males, stamens 4 to 30; females, stigmas, two to four-cleft; capsule two-celled, loculicidal. Known species 18, from the N. temperate zone. Two, Populas alba, the great white poplar or abele, and P. tremula, the trembling poplar or aspen, lar, is only naturalized. The first is a are indigenous. P. nigra , the black poplarge tree with downy , but not viscous buds. It grows in moist places and mountain woods. The timber is white, soft, and used only for coarse work. The bark is said to be useful in strangury. For the second species, see ASPEN. P. nigra has viscid buds, leaves grows in moist places, on river banks, etc. The wood is light, and not very suborbicular. It valuable. It is used for carving, or burnt for charcoal, and the bark employed for tannin. P. monilifera is the black Italian poplar, P. fastigiata, the Lombardy poplar, and P. canadensis, the Canadian poplar. The buds of P. nigra, the Himalayan P. balsamifera, P. candicans, etc., are besmeared in winter with dation, called tacamahac, considered to a resinous balsamic, bitter , aromatic exube diuretic, and antiscorbutic . The bark of P. euphratica is given in India as a vermifuge. The poplar occurs in the Cretaceous rocks of North America, the Eocene of Bournemouth , and the Miocene of Continental Europe. watered, figured, brocaded, or tissued.
Aiton's Encyclopedia (1910)
a familiar tree of the north temperate zone. There are twenty-five or thirty species. In England the poplar often goes by the name of aspen. The leaves of an aspen or poplar have leaf-stalks so narrow in proportion to their height that the leaves sway sideways easily and flutter in the slightest breeze. Hence the expression "tremble like an aspen." Poplar wood is white and easily carved. It is a favorite material for woodenware. In the United States and Canada printing paper is made from poplar with the admixture of spruce pulp to give toughness. The cottonwood and balm of Gilead are near relatives of the poplars, and willows are not far distant. The flowers of the whole family resemble those of the willow. The cottonwood is a kind of quick-growing poplar, invaluable as a wind break on the prairies where other trees do not grow well, but not desirable as a park tree on account of the "cotton" which flies incessantly when the seed pods burst. In June wind carries the seed hundreds of miles. The poplar accompanies the willow and the birch to the northern limit of trees.
What Has Changed in the Last Century
The botany in Collier's 1921 list has largely held: Populus is still a genus of the willow family with roughly 30 species, though several of its names have been demoted — the Lombardy poplar is now treated as a cultivar of the black poplar, Populus nigra 'Italica', and the "Canadian poplar" as the hybrid P. × canadensis. What has gone is the pharmacy: nobody now prescribes poplar bark for strangury or tacamahac as an antiscorbutic, though the salicin in the bark is chemically kin to aspirin. Aiton's 1910 note that poplar makes printing paper with spruce pulp proved prophetic — fast-growing hybrid poplars are now farmed in short-rotation plantations for pulp, plywood and biofuel. In 2006 Populus trichocarpa, the black cottonwood, became the first tree to have its full genome sequenced, and quaking aspen is now known to form vast single clones, the Utah colony called Pando covering some 43 hectares.
Written for this edition, 2026.