Alnilam

[Corrupted Arabic.] A fixed star of magnitude 24, called also e Or i on is. ǎl'-nūs, s. [Lat.] [ALDER.] Bot. A genus of plants belonging to the order Betulaceae (Birch-worts). The flowers are monœcio us and amentaceous. In the barren ones the scale of the catkin is three lobed, with three flowers; the perianth is four partite the stamina, four. In those which are fertile the scale of the catkin is sub trifid with three flowers, and there is no perianth. The ovary is two-celled, two-ovuled, but only one ovule reaches perfection. The only British species is A. glutinosa , the Alder (q.v.).