Betula pubescens Betula pubescens Betula pubescens (syn. "Betula alba"), commonly known as downy birch and also as moor birch, white birch, European white birch or hairy birch, is a species of deciduous tree, native and abundant throughout northern Europe and northern Asia, growing farther north than any other broadleaf tree. It is closely related to, and often confused with, the silver birch ("B. pendula"), but grows in wetter places with heavier soils and poorer drainage; smaller trees can also be confused with the dwarf birch ("B. nana"). Three varieties are recognised and it hybridises with the silver and dwarf birches. A number
Northern rough-winged swallow Northern rough-winged swallow The northern rough-winged swallow ("Stelgidopteryx serripennis") is a small, migratory swallow. It is very similar to the southern rough-winged swallow, "Stelgidopteryx ruficollis". The genus name, "Stelgidopteryx", is from Ancient Greek and means "scraper wing" and the species name, "serripennis", is derived from Latin and means "saw feather". In the common name, "rough-winged" refers to the serrated edge feathers on the wing of this bird; this feature would only be apparent when holding this bird. Six subspecies of the northern rough-winged swallow are currently recognized. It has been proposed that another race be recognized, "aphracta", but this is