alder tree are trees that compose the genus Alnus in the birch family Betulaceae . The genus includes about 35 species of monecious tree and shrubs , a few reach a large size of it , hand out throughout the northward temperate geographical zone with a few species extending into Central America , as well as the northern and southern Andes .
Alders can be trees or large shrubs . bet on the species , they can grow from little , multi - caulescent bush to tall trees up to 35 meters in height . The leaves of alder tree are commonly elementary , alternative , and can range from broadly ovate to elliptical . They often have serrated or double - serrate bound . Some mintage have leaves with a typical shape , like the deep lobed leaves of certain cultivars . The color is typically a vivacious green , though some species or varieties might show edition like gray or blue hues below .
Young alder have politic barque , often with a grey or greenish color . As they age , the bark can become more textured , fissured , or even scaly . Some species have bark that ’s used for natural dyes .
Alders are monoicous , they have both male and female flowers on the same tree . manlike catkin are longsighted , pendulous , and come along in clusters . Female catkins are smaller , upright when pollinate , and recrudesce into woody cone cell that hold back seeds . After pollination , female catkins make grow into humble , woody , cone - like structures that persevere on the tree , often through winter . These retinal cone release tiny winged seeds .
Many alder species are deciduous , losing their leaves in fall . Before fall , leaves might turn a yellowish color , though this is n’t always particularly vibrant . Alder species flourish in wet soils and are often found along riverbanks , in wetland , or in floodplain . They can tolerate implosion therapy and help stabilize riverbanks .
Alder Trees
Common Alder ( Alnus glutinosa )
Red Alder ( Alnus rubra )
Italian Alder ( Alnus cordata )
White Alder ( Alnus rhombifolia )
Speckled Alder ( Alnus incana rugosa )
Grey Alder ( Alnus incana )
Black Alder ( Alnus glutinosa ‘ Laciniata ’ )
Japanese Alder ( Alnus japonica )
Green Alder ( Alnus viridis )
Sitka Alder ( Alnus viridis sinuata )
Mountain Alder ( Alnus tenuifolia or Alnus incana tenuifolia )
Alder Buckthorn ( not a true alder , but often confused with them , Frangula alnus )
Hazel Alder ( Alnus serrulata )
Seaside Alder ( Alnus maritima )
Nepalese Alder ( Alnus nepalensis )
Peruvian Alder ( Alnus acuminata var . peruviana )
Manchurian Alder ( Alnus mandshurica )
Black Alder ( Alnus glutinosa )
