This is one of the forms with which I have had no trouble. It has been growing here for ten years and, planted among bricks, it has not spread much beyond where I first planted the bulbs. I have seen no seedlings, I am glad to say. In individual containers it behaves well. Flowering lasts from late December until early February. The original bulbs came from Bill Dijk via Cathy Craig. Possibly these differ from what you saw in Portugal. The single form, the terror of the genus, has been almost extirpated on the property and if an individual appears it is contact - treated with Roundup. Andrew San Diego