Wind-pollinated flowers appear before leaves; seed matures as leaves develop. Seeds are tipped with long, silky down (cotton) for wind distribution. The widespread, shallow root system facilitates regeneration by "suckers" on cutover and burned land. Abundant suckers allow single trees to produce copses of clones with identical characteristics (eg, early leafing or late retention of autumn colour). Rapid growth makes poplars useful for reclamation. In ideal conditions, pulpwood is produced in 10 years, small sawlogs in 15 and veneer stock in 20. Infertile hybrids that produce no "cotton" have been cloned for ornamental plantings. Natural hybridization is common and causes difficulty in defining species.
Links to Other Sites
The Plant List
Search this online database for information about one million plant species from around the world. Also, click on "major plant groups" at the bottom of the page to browse descriptions of species of interest. Fungi and algae are excluded. From the Royal Botanic Gardens, Kew, in the UK and the Missouri Botanical Garden in the US.
Flora of North America
The FNA website features information on the names, taxonomic relationships, continent-wide distributions, and morphological characteristics of all plants native and naturalized found in North America north of Mexico.