Medical Definition of ERYTHROPOIESIS. : the production of red blood cells (as from the bone marrow)âcalled also erythrocytopoiesis, erythrogenesis. â erythÂ·roÂ·poiÂ·etÂ·ic \-Ëet-ik\ adjective.
Horticultural. Pop ash has several redeeming characteristics that make it an interesting, attractive, and useful landscape tree. Its small to medium size, wide spreading crown, crooked and multi-stemmed trunk, glossy and compound leaves, and fast growth rates make it a decorative addition to landscapes.lowers are 1/8 inch long and bloom in early spring before leaves emerge. The blooms appear in clusters of many yellow (male) and green (female) flowers. Fruits are 1Â½ to 2 inch long elliptical samaras (winged seeds) that have 1 wing (or occasionally 3).
Just as the height of the tree varies among species, so do the Birch's other characteristics: 1  Leaves: The leaves of the Birch tree are typically oval to elliptical-shaped. 2  Bark: Birch trees are known for their unique bark. 3  Flowers: The Birch tree produces flowers known as catkins.mong the most notable types are: 1  Paper Birch: Native to North America, the Paper Birch is treasured for its ornamental value. 2  The tree has a creamy white bark and delicate green leaves. 3  It is one of the largest Birches and can reach heights of 80 feet.