I have found the following two flowers growing at various locations in West Central Indiana. The yellow, daisy-like flowers, which I found growing at a local park, were about three feet tall when I took this picture on July 21 of this year. The thistle species, which I have found growing in abundance primarily in uncultivated or abandoned fields, generally ranges from two to five feet tall. The picture here was taken on August 18 of this year and the plant was about four feet tall. I've tentatively identified the thistle species as bull thistle, Cirsium vulgare, but am uncertain about the identification. Any help in identifying these two species would be greatly appreciated.