Alnus is also known as the Adler Tree. The flower clusters on the alnus glutinosa tree are known as catkins which are large, long, and shaped like a cylinder.

Alnus Glutinosa Catkins and Fruit

Alnus is also known as the Adler Tree. The flower clusters on the alnus glutinosa tree are known as…

"A tree which grows plentifully in Europe and in Siberia. It is a native of Britain, and is frequent in Scotland, where it is found even at an elevation of 1500 feet above the sea. It has recieved the specific name tremula, from the readiness with which its leaves are thrown into a tremulous motion by the slightest breath of wind. a, a portion of a branch with catkins; b, do., with leaves." — Chambers' Encyclopedia, 1875

Aspen

"A tree which grows plentifully in Europe and in Siberia. It is a native of Britain, and is frequent…

The female flowers of a catkin from the Common Aspen (Populus tremula).

Common Aspen

The female flowers of a catkin from the Common Aspen (Populus tremula).

"Male and female catkins of Betula alba." -Lindley, 1853

White Birch

"Male and female catkins of Betula alba." -Lindley, 1853

"Scotch Pine (P. slvestris). 1, a twig showing: a, staminate catkins; b, pistillate catkins; c, a cone; d, needles. 2, an anther, a, side view; b, outer surface. 3, a carpel-scale, a, inner surface; b, outer surface. 4, a cone-scale, a seed-wing, and a seed. 5, section of a seed, showing the embryo." -Bergen, 1896

Scotch Pine

"Scotch Pine (P. slvestris). 1, a twig showing: a, staminate catkins; b, pistillate catkins; c, a cone;…