“Ahem, ahem, cough, cough,” I would say, but there is not really an onomatopoetic word for the sound you make when you cough.
“Ahem” is really more of an “excuse me, I want to interrupt” word and not a full blown cough. I mention this because the sap of the Curly-cup Gumweed is used by Native Americans when a ticklish and persistent cough arises.
It is late June and early August in Kansas, time for the Curly-cup Gumweed to bloom.
One can find the Curly-cup Gumweed along the paths in many state parks and along roadsides in the country. Its roots can grow to six feet in length making it drought resistant. The stems are knee high to thigh. The alternating leaves are spiky and therefore unpalatable to cattle. Like an artichoke, the dozens of sepals that surround the flowering head also serve to protect the flower from deer. The flowers spread out from a central stem in a beautiful display of bright yellow. Called Gumweed because of its milky sap, which Native Americans used on poison ivy rashes and saddle sores, as well as coughs, colds, and tummy aches.
Wildfoodgirl gives out culinary tips in a post called, Expectorating with Gumweed.