Funastrum hirtellum is a species of the Mojave Desert, its range extending to scattered locations in north Arizona. Stems and leaves are greyish-green in color, and have a dense covering of very short, spreading hairs. The opposite, quite widely separated stem leaves are long and narrow, tapering gradually towards the tip. Plants often produce many stems, winding and vine-like, forming a tangled clump.
Flowers form in compact, spherical clusters which typically contain around ten heads, held on short, equal-length pedicels. Individual flowers have five narrow green sepals below and between five larger, white to pale yellow-green petals, spreading or ascending, partly curved inwards towards the tips. At the flower center are five white appendages surrounding a column of fused anthers and a pistil.