Seeds Golden Black Eyed Susan Vine or Thunbergia alata. This annual grows very rapidly covering a trellis easily in a couple of months and is very easy to let just wander. The bright golden blossoms with a black center cover this plant from mid summer until late fall and always seem to have some flowers in blossom. These will self sow as you would many annuals and in the spring. I have mine growing up my front bay window frame and even though this is supposed to be an annual, I have had it in bloom for three seasons now. Zones 9 to 11.