The vouchered species are so marked on the list. Ultimately, all species on the list should be backed up by at least one voucher, preserved, preferably, in a permanently maintained repository. This should include not only the weeds but also the cultivated species that have become naturalized. For the sake of the Park's records and its visitors, the purely cultivated species should also be listed and vouchered, so that the Park has an absolutely complete list of its vascular flora. There are always many problems in this kind of inventory.
Different collectors appear to be calling different things pumpkin ash.
What should be regarded as purely cultivated vs. naturalized can be a troublesome problem. Identifying the cultivated species can also be a major task if planting records have not been kept meticulously over the years. Because I'm working on the local flora, I'm obviously interested in what occurs there and hope to get back on occasion. I'll do what I can but cannot volunteer to complete the job that Peggy, Raclare, and others have so ably begun. If resident staff make collections, I'll try to be helpful in naming them, so long as the numbers are not overwhelming.