Ornithogalum
Angelo Porcelli (Sat, 03 Jun 2006 03:16:56 PDT)

Some Ornithogalum are indeed invasive, like O.umbellatum and arabicum, but
this is due to the excessively fertile soil. In habitat O.umbellatum isn't
at all invasive and it grows usually in small clumps or lonely. O.arabicum
also proliferates with an abnormal number of bulbils, which make a clump of
leaves with no flowers in the following years and thus it needs to be digged
and clean from all offsets and replant only the biggest bulbs. But other
species like O.montanum and O.comosum are non offsetting even in cultivation
and are worth to pot culture

Angelo Porcelli
Italy