Hi Greenman
'Alba form' I am afraid is a very broad term and
effectively could be any of the species. As to the leaves falling off, well this is not what I would call congenial, with out seeing the plant I would suggest it has a problem more than likely water based ie:- not enough or maybe even to much, to much sun is another possibility etc. If you can post a closeup pic of the plant roots & bulbs etc I may be able to tell you more.
Cheers Craig
