Caps up to 10 cm broad, at first clavate, the apex truncate, expanding to form a vase-shape fuiting body, one side typically showing greater developement than the other; margin undulate to lobed, upturned in age; surface moist, soon dry, smooth to finely squamulose, especially near the disk, the latter often depressed; lavender-purple to purple-brown when young, fading to buff-brown in age, the margin sometimes retaining lilac tones; flesh thick, white to pale buff; odor and taste mild, of mushrooms.
Fertile surface decurrent, varing from blunt, interconnecting ridges to anastamosing veins, and wrinkles, occasionally nearly poroid; lilac-purple to purple-brown fading in age.
Stipe up to 5 cm long, 1-3 cm thick, short, solid, sometimes hollow at maturity, central to laterally attached, tapering downward, the apex merging with and indistinguishable from the hymenium/cap; often fused at the base with adjacent fruiting bodies; surface slightly fibrillose to hairy, lilac-brown apically, white to pale brown below; flesh white, unchanging.
Spores 10-14 x 5-7.5 µm, elliptical, wrinkled to slightly warted, nonamyloid; pale yellowish-buff in deposit.
Singly, in cespitose clusters and arcs under conifers; fruiting from late fall to mid-winter.
Described as edible and choice by some authors, but usually regarded as mediocre locally; often infested with fly larva.
Gomphus clavatus is characterized by a clustered habit, lilac-colored, wrinkled hymenium and club-shaped to partially funnel-shaped fruiting body. The lilac color easily distinguishes it from Gomphus floccosus f. floccosus and G. bonari.