The History of the London Plane

Abstract

IN an article on “The Artificial Production of Vigorous Trees,” an abstract of which was pub lished in NATURE, January 7, 1915, p. 521, Prof. Augustine Henry directed attention to certain well-known trees, like the Lucombe oak, Huntingdon elm, cricket-bat willow, and black Italian poplar, which owe their vigour and botanical characters to the fact that they are of hybrid origin. Such hybrids arose as chance seedlings due to cross-pollination of two trees of different species growing together. The introduc tion into Europe during the seventeenth centurv of North American trees which grew alongside similar, but distinct, European species in parks and gardens was the occasion of considerable hybridisation. Trees like the black Italian poplar and the London plane, which have never been seen anywhere in the wild state, are intermediate in botanical characters between an American and a European species in each case, and are undoubtedly first-crosses.