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ALDERS. 
Natural Order , Ament ace a:, (Jussieu.) Linnxan Classi- 
fication, Mongccia, Tetrandria. 
Genus ALNUS. (Tournefort, Decandolle.) 
Character. The flowers are monoecious , (or of two different 
kinds on the same plant,) disposed in catkins, (or cylindric 
spikes of short duration,) those producing the stamens are 
long and cylindric; those of the fruit or seed are ovoid or 
globular, produced upon branching peduncles. The scales of 
the male flower are pedicellated, and in the form of an in- 
verted heart, bearing beneath each 3 lesser scales; the proper 
flowers are situated at the base of each of these, and are com- 
posed of a cup with 4 lobes and 4 stamens. The scales of the 
fruiting catkins are wedge-shaped, hard, and persistent. The 
ovary is compressed, and bears 2 long stigmas. The envelope 
of the seed is hard, with a border which is either thick or 
membranaceous, and presents 2 cells with 2 seeds; the ovules 
in the germ are about 4, or 2 in a cell, 3 of them usually 
abortive. 
The plants of this small genus, confined to the temperate 
or colder parts of Europe and North America, are either shrubs 
or trees, with deciduous leaves, generally growing by streams, or 
in cool and humid places. As trees they seldom attain a greater 
elevation than 30 to 40 feet; the wood is hard and yellowish, 
becoming of a brownish-red, nearly like mahogany, when ex- 
posed to the air, and capable of acquiring a fine polish. When 
stained black it resembles ebony, and it is capable of enduring 
moisture for a great length of time. 
The Alders may be divided into the two following sections; 
in both the peduncles are subdivided. 
