I finally got my answer from the NWTF on CHUFA plantings.. My question below.... and the answer from the NWTF.
Q: In Washington, we need more solid evidence to prove to the government that chufa nutsedge is different than yellow nutsedge. They are different subspecies, but they get lumped into the same category out here. With the info I have above, I'd like to know the scientific name or variety of chufa. In Washington and other states Cyperus esculentus eptostachyus is an introduced yellow nutsedge and in the South Cyperus esculentus macrostachyus is a native variety. Is chufa a cultivated genotype of the native or the non-native? I want to plant chufa for wild turkeys but I hit roadblocks with agencies that consider chufa a noxious weed.
A: There are a number of references in scientific literature and on the Internet to yellow nutsedge and its relationship to chufa. Both are the same species but they are very different variants. Generally, most authorities agree that the weedy, invasive type (yellow nutsedge) is Cyperus esculentus var. esculentus, and the cultivated, non-invasive variety (chufa) is Cyperus esculentus var. sativus.
Research by Dr. Andrew Dyer at the University of South Carolina (Aiken branch) has shown that the two variants are quite different in physiology and reproductive capability. Nutsedge produces a widespread network of tubers and roots and chufa produces a compact ball of tubers directly under the center of the leaves. Nutsedge flowers early in the summer, and chufa, if it flowers at all, does so in late summer or early fall. This means the likelihood of hybridization is near zero.
Dyer has suggested that the two variants are so different that they may deserve distinct species status. Nutsedge is also invasive, spreading quickly if introduced. Chufa will not spread from a planting site, and in fact, since it does not compete well with other vegetation, will quickly die out if not maintained.