Uli: We have the Oxalis pes-caprae in the Azores. There are some of the little squares that the farmers have that are completely yellow with them. Cows won't eat them so there is no control.
The wild Allium is probably A. subvillosum, commonly called Wild Garlic. I have a few plants growing wild, but it needs to be thinned every couple of years. I do have another Allium that has fairly small bulbs and stalks that are 2 meters tall with purple flowers. I pull it out and it keeps returning - it is also in flower now.
Hedychium gardnerianum is an invasive rhizome. But the leaves are used when making traditional bread. My house has a traditional oven. It looks like a giant pizza oven and is built of lava rocks to help retain heat. You make the fire inside of it and then put the dough wrapped in the Hedychium leaves off to the side to bake. It grows in just about every dry stream bed on every island in the Azores. Tourists like it, so they don't go overboard pulling it out.
The wild Allium is probably A. subvillosum, commonly called Wild Garlic. I have a few plants growing wild, but it needs to be thinned every couple of years. I do have another Allium that has fairly small bulbs and stalks that are 2 meters tall with purple flowers. I pull it out and it keeps returning - it is also in flower now.
Hedychium gardnerianum is an invasive rhizome. But the leaves are used when making traditional bread. My house has a traditional oven. It looks like a giant pizza oven and is built of lava rocks to help retain heat. You make the fire inside of it and then put the dough wrapped in the Hedychium leaves off to the side to bake. It grows in just about every dry stream bed on every island in the Azores. Tourists like it, so they don't go overboard pulling it out.