Cap 5-13 cm broad, convex, nearly plane in age; margin incurved when young with cottony, white velar tissue; surface viscid, smooth, white, becoming grey with olive tones, at maturity various combinations of rusty-brown, reddish-brown or a dull yellowish-brown, the latter typical of old fruiting bodies; flesh white, turning yellow at maturity, not bruising blue; odor and taste fruity but harsh.
Pores at first white to cream, exuding white droplets in moist weather; in age pores yellowish to dingy, yellow-brown, not bruising blue.
Stipe 3-8 cm tall, 1.5-2.0 cm thick, equal, sometimes tapering slightly to the base; surface dry, white to pale yellow, dotted with buff-colored glands that at maturity become dark-brown; flesh not bruising blue.
Spores 9-10 x 3-3.5 µm, elliptical, smooth; spore print brown.
Scattered to gregarious under Monterey pine (Pinus radiata); fruiting sporadically in watered areas during the summer months; often in large numbers after the fall rains.
Edible, but not choice, due to a soft texture and harsh flavor; like many boletes, it frequently is infested with fly larva; young specimens are sometimes dried or pickled after peeling the slimy cuticle.
Suillus pungens fruits abundantly under Monterey pine, frequently in the company of Chroogomphus vinicolor, the pine spike. This "slippery jack", so named because of its slimy cap, undergoes a series of color changes starting out white, then grey with touches of olive, finally a mixture of rusty-brown and yellow-brown tones. The pungent odor and milky droplets on the pores of young specimens are also important field characters.