Dear Christian, Before I joined our little group I was aware this weed existed., but I did not know it was taking over the world. In central Arizona where I live this weed barely survives. Some years we only get a couple inches of rain. In the summer it can hit 125F. While I do grow a lot of desert plants in the ground I find it so much easier to grow most of my bulbs in pots. For those people that do not care to use chemical weedkillers you better hire a full time gardening staff to dig out the roots,especially before the plants go to seed and spread.I have been involved in agricultural pest control loner than most of you have been alive and I really cannot see any easy solution for getting rid of this weed. You will certainly improve your heart function from all the exercise digging it out. It sounds like many of our grower raise more of this weed than garden flowers. If you went out every week and chopped off all the green leaves you will probably kill off some this nasty thing but you will really have to commit to this program. The seeds sound like they can live a long time. Common ragweed seed can sprout after being buried for five years. So I think you are looking at a lifetimes work to control this by hand methods-Russ H Please understand I do not mean to criticise gardeners that don't use chemicals. Everyone has a right to decide how they want to run their business. That is as long as it does no harm to others. In a message dated 4/5/2013 3:44:53 A.M. Pacific Daylight Time, christian.lachaud@gmail.com writes: Kathleen : ok ! Some of them look very similar indeed. I think we have only one though, considering morphology, natural geographic distribution, and environmental requirements (for instance, the last one in your list seems to like damp soils). If population of Cardamine was heterogeneous with different species, how do you think it would modify the global pattern of invasiveness and what seems to be seeds reaction to roundup ? Look at that one : Holly sh. !!! (that's how it looks here on hopefully small patches where rounduped) http://www.flickr.com/photos/hommfarm/7012233943/ *Dr. Christian M. Lachaud, PhD* _________________ http://www.saffron-crocuses.com/ _______________________________________________ pbs mailing list pbs@lists.ibiblio.org http://pacificbulbsociety.org/list.php http://pacificbulbsociety.org/pbswiki/