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Populus Sect. Aegiros
''Populus'' section ''Aigeiros'' is a section of three species in the genus ''Populus'', the poplars. Like some other species in the genus ''Populus'', they are commonly known as cottonwoods. The species are native to North America, Europe, and western Asia. In the past, as many as six species were recognized, but recent trends have been to accept just three species, treating the others as subspecies of ''P. deltoides''. They are large, deciduous trees that are tall and diameters of , distinguished by thick, deeply fissured bark and triangular-based to diamond-shaped leaves that are green on both sides (without the whitish wax on the undersides) and without any obvious balsam scent in spring. An important feature of the leaves is the petiole, which is flattened sideways so that the leaves have a particular type of movement in the wind. Male and female flowers are in separate catkins, appearing before the leaves in spring. The seeds are borne on cottony structures that allow t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean Étienne Duby
Jean Étienne Duby (15 February 1798 in Geneva – 24 November 1885) was a Swiss clergyman and botanist. He studied theology in Geneva, obtaining his consecration in 1820, and having an avid interest in natural history, he earned his degree in natural sciences in 1824. As a young man he was influenced by Augustin Pyramus de Candolle (1778–1841), and made contributions towards Candolle's publication of ''Botanicon gallicum; seu Synopsis plantarum in Flora gallica descriptarum'' (1828-1830). From 1831 to 1863 he served as a pastor in Eaux-Vives, Geneva, while in the meantime playing an active role in botany. He specialized in research of cryptogams, including studies of European and exotic mosses, and taxonomic work involving the red algae genus ''Ceramium''. In addition to his work with cryptogams, he conducted studies on the flowering plant family Primulaceae. In 1860–61 he was president of the ''Société de physique et d'histoire naturelle de Genève''. He was also a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
