First collected in 2002 on Santa Cruz Island off the coast of California, in association with Bishop Pine (Pinus muricata), the species was scientifically described and named in 2010.

It resembles Suillus brevipes, but can be distinguished from that species by its paler-colored immature cap and by the tiny colored glands on the stipe that darken with age.

The specific epithet quiescens refers to the organism's ability to wait dormant (quiescent) in the soil until it encounters pine roots.

[2] S. bellinii S. pungens S. glandulosipes, S. neoalbidipes S. granulatus S. occidentalis S. pseudobrevipes, S. volcanalis S. luteus S. brevipes, S. weaverae S. granulatus, S. collinitus S. collinitus S. quiescens Based on phylogenetic analysis of the internal transcribed spacer region in the non-functional RNA of a number of Suillus species, S. quiescens is distinct from other morphologically similar species such as S. brevipes, S. volcanalis, and S. occidentalis.

Another study showed that viable S. quiescens spores were present in steam-pasteurized soil planted in Oregon fields.

[5] The authors suggest that S. quiescens is an early successional species that fruits in young forests, and whose spores remain dormant in the soil for extended periods of time until the roots of a suitable pine host are encountered.