A beautiful ivy has appeared next to my pond in Central Texas. It's a great ground cover, that seems to be tolerant of this harsh environment. This is an area in which I have had no success growing things in the past (including some rather expensive native Texas grass seed). I would like to propagate this further, and have even collected several ounces of seeds. However, before I proceed, I want to make sure I will not be creating more problems for myself by spreading an invasive species. Can someone help me to identify it?

The plant does not appear to be English ivy, as its leaves are much narrower. In addition, the flowers and seeds of this plant are nothing like English ivy. For the last few weeks this plant has been producing small, yellow flowers that lead to the production of a seed pod that looks exactly like a string bean. The pods darken and eventually burst open when dry.

Here are some additional photos:

http://s8.postimage.org/5g0r13nv9/ivy1.jpg

http://s8.postimage.org/jnqfpr0k5/ivy2.jpg

http://s8.postimage.org/7adliuavp/ivy3.jpg

http://s8.postimage.org/o1yx1lb4l/ivy4.jpg

http://s8.postimage.org/xcfmivb85/ivy5.jpg

http://s8.postimage.org/shlxklcwl/ivy6.jpg

http://s8.postimage.org/pc1buduad/ivy7.jpg

Any guesses?

H