Alder

Alnus spp.

• Height: up to 25 m
• Trunk: blackish-brown bark, longitudinally fissured, with orange-yellow lenticels, often multi-stemmed
• Leaves: alternate, obovate, broad to rounded, indented at the tip, coarsely serrated margin, glossy dark green upper side, lighter underside, petiolate
• Buds: sticky buds and young shoots
• Flowers: 6–10 cm long, limp, pendulous male catkins, initially purplish-red, turning pale yellow when pollen is released; female catkins elongated-oval, purplish-red, at branch tips, appearing before leaf emergence in February to April
• Fruits/Seeds: small, up to about 2 cm in size, woody, black-brown fruit cones (the only deciduous tree to produce them), winged nuts sit between woody bracts
• Other: sheds green leaves, has root nodules for nitrogen fixation
  

^{Photos: BUND Naturschutz in Bayern (1,2,3)}