Pyramidal Black Alder - Alnus glutinosa 'Pyramidalis'

Pyramidal Black Alder - Alnus glutinosa 'Pyramidalis'
Birch Family: Betulaceae
Height: to 60 feet / USDA zones 4-7

Black Alder is monoecious, that is, it has both male and female flowers on the same plant. Pollen is transmitted from male to female via wind.
In this case, the male catkins, or ament, are seen on the left, and the female strobili are on the right.

European Black Alder, a native of Europe, northern Africa, and western Asia, was introduced to North America long ago and has escaped from cultivation, and it is sometimes seen along bodies of water, where it may successfully self-sow and form pure stands. Today, it is grown as a shade tree in urban areas, or at wet sites (ponds, creeks, drainage ditches, etc.) where it thrives and provides both erosion control and ornamental appeal.

European Black Alder is adaptable to a wide range of favorable or harsh environmental conditions. It prefers moist to wet soils of variable pH that are rich and deep, but adapts to average or poor soils that are dry in summer. Growth is especially rapid in occasionally wet to permanently wet areas, such as floodplains , streambanks, and ditches.

European Black Alder has a leaf that is atypical as compared to other Alders in that it is round in shape, rather than elliptical. In addition, some leaves have a distinct notch at the apex, which is not obvious until the leaves are fully expanded.

Economic importance:

Environmental: erosion control; ornamental; soil improver
Materials: wood (timber fide Ency WTimber; F NAmer)
Medicines: folklore (fide CRC MedHerbs ed2; Herbs Commerce ed2)
Weed: also potential seed contaminant (fide Rep NCEPPC)

Native:

AFRICA
Northern Africa: Algeria; Morocco; Tunisia
ASIA-TEMPERATE
Western Asia: Iran; Turkey
Caucasus: Russian Federation - Ciscaucasia
Siberia: Russian Federation - Western Siberia
Soviet Middle Asia: Kazakhstan
EUROPE
Northern Europe: Denmark; Finland; Ireland; Norway; Sweden; United Kingdom
Middle Europe: Austria; Belgium; Czechoslovakia; Germany; Hungary; Netherlands; Poland; Switzerland
East Europe: Belarus; Russian Federation - European part; Ukraine [incl. Krym]
Southeastern Europe: Albania; Bulgaria; Greece; Italy; Romania; Yugoslavia
Southwestern Europe: France; Portugal; Spain

Common names:

black alder (Source: F USSR )
European alder (Source: Dict Gard )
swartels (Source: Weeds SAfr 2001 ) [Afrikaans]

check MMPND for additional names in foreign scripts

Synonyms:

(=) Alnus barbata C. A. Mey.
(previously associated with 1 accession)
(=) Alnus glutinosa subsp. barbata (C. A. Mey.) Yalt.
(=) Alnus glutinosa var. barbata (C. A. Mey.) Ledeb.
(≡) Betula alnus var. glutinosa L. (basionym)
(≡) Betula glutinosa (L.) Lam. [1]

Pyramidal Black Alder male catkins
Black Alder Male Catkins

The Invasive Plant Atlas of New England (IPANE) , says "(Alnus glutinosa) bark is smooth and dark brown.

The fertilized female flowers become cone-like, green fruits by late spring, and as they grow throughout the summer, they often weigh down the branches that support them. In autumn, the seeds are released as the cones open and the remaining structures (called strobiles) persist on the twigs.
References
1. USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?2448 (31 May 2008)