Littlehead Gumweed Grindelia microcephala a North American species of flowering plants in the daisy family. It is native to the south-central United States, having been found only in the State of Texas.an annual herb up to 40 cm 16 in tall; plant usually produces numerous flower heads in open, flat-topped arrays. Each head has 16-27 ray flowers, surrounding a large number of tiny disc flowers shown in a pasture setting with rusty barbwire fence