Alder
Latin name:
Alnus glutinosa, A. incana, A. viridis
Description:
These trees grow mostly on moist places, for instance along river-sides. In the beginning, the male catkins are dark brownish-red, they turn into yellowish-red at maturity time.
Start of the season:
Flowering time is about the same as it is for hazel (that is at the end of December whenever temperatures rise significantly above 5 degrees Celsius), but alders require slightly higher temperatures for pollination.
A. viridis flowers from end of May to June in Alpine regions at timber line.
Allergenicity:
Alder is known for moderate to high allergenicity.
Both alder and hazel pollen cross-react with birch pollen. Very sensitive birchpollen-allergic subjects will suffer when hazel- and alder pollen are in the atmosphere.
