Silver wattle

An Australian Acacia used in the floral trade with finely divided leaves and yellow puffball flowers that are present late winter/early spring. According to Wiikipedia, the plant does not tolerate prolonged frost. These have flourished during a period of 5 years with periods of deep freeze up to a week long with temps not coming up past 40f(which for us is extremely cold) Not sure when they were introduced, but like the gorse there are many groupings of naturalized trees forming thick patches