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24. Black Alder
Winona State University has a small to medium-sized Alder species represented on campus by means of the selection of the Black Alder (Alnus glutinosa).
The Alder is a member of the Birch family (Betulaceae). The Black Alder, also known as the European Black Alder, was brought to North America from Europe and is commonly found along streams. The four-inch long leaves are dark green on the top and very light on the bottom. Greenish-yellow catkins with numerous tiny flowers are displayed in early spring before leaves appear.
Both male and female catkins appear on the same tree. The female catkins are replaced by small, brown, woody cone-like fruits which remain on the tree most of the year. The persistent fruit make this a tree of significant winter interest especially when viewed in silhouette against the sky or the white of new-fallen snow.
The Black Alder is a hardy tree, surviving northern winters well, though it does better in wet sites and can be short lived if grown in dry, stressful sites. The Alder is one of the few tree varieties that convert nitrogen from the soil atmosphere enabling it to grow and prosper even in adverse conditions. The Black Alder grows to average heights of 30 to 50 feet.
At Winona State University, the Black Alder can be found in two separate islands along the central campus mall; one just west of the entrance to the Library and the other just east of Minné Hall. Several Black Alders are also located along the west side of Watkins Hall.
(see #18 on the maps)
Last Modified: Thursday, May 08, 2008 13:59 by