The subterranean traps are white, lacking chlorophyll or any other pigmentation. They consist of a cylindrical stalk, widening at some distance below the surface into a hollow bulb-like utricle, and continuing as a hollow cylinder some further distance. At this point the stalk into two furrowed spirals, between which the cylinder opening acts as the trap entrance. The furrows of the spiraled trap arms are lined with hairs pointing inward and toward the bifurcation. The hollow cylinder section leading from the bifurcation to the utricle is likewise lined with upward-pointing curved hairs. Some species produce two trap forms, one shorter and one longer, which probably target different prey groups.