 | This article needs to beupdated. The reason given is: Article largely unchanged since 2010.S. quiscens has since been found as an introduced species in New Zealand and in association with host pines not mentioned in this article; see talk page. Please help update this article to reflect recent events or newly available information.(June 2025) |
| Suillus quiescens | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Boletales |
| Family: | Suillaceae |
| Genus: | Suillus |
| Species: | S. quiescens |
| Binomial name | |
| Suillus quiescens T.D.Bruns & Vellinga (2010) | |
| Suillus quiescens | |
|---|---|
| Mycological characteristics | |
 | Pores onhymenium |
 | Cap is convex |
 | Stipe is bare |
 | Spore print is brown |
 | Ecology ismycorrhizal |
 | Edibility isunknown |
Suillus quiescens is apored mushroom of the genusSuillus in the familySuillaceae. First collected in 2002 onSanta Cruz Island off the coast ofCalifornia, in association withbishop pine (Pinus muricata), the species was scientifically described and named in 2010. In addition to its distribution in coastal California, it was also found formingectomycorrhizae with the roots of pine seedlings in the easternSierra Nevada, coastalOregon, and the southernCascade Mountains. It resemblesSuillus brevipes, but can be distinguished from that species by its paler-colored immaturecap and by the tiny colored glands on thestipe that darken with age.
Fruit bodies of the fungus were first collected in 2002 on Santa Cruz Island, inSanta Barbara County. They were named provisionally as a new species,Suillus quiescens, in conferenceproceedings published in 2005.[2] The species was officiallydescribed and named in a 2010Mycologia publication. Thespecific epithetquiescens refers to the organism's ability to wait dormant (quiescent) in the soil until it encounters pine roots.[3]
| Phylogeny and relationships ofS. quiescens and otherSuillus species based onITS sequences.[3] |
Based onphylogenetic analysis of theinternal transcribed spacer region in the non-functionalRNA of a number ofSuillus species,S. quiescens is distinct from othermorphologically similar species such asS. brevipes,S. volcanalis, andS. occidentalis. TheS. quiescens sequences, which were obtained from fruit bodies and from mycorrhizal root tips, formed a clade.[3] The analysis showed that theS. quiescens sequences were matches to some unidentifiedSuillus sequences found from mycorrhizae of pine seedlings collected from Oregon[4] and California.[3][5]
Thecap ranges in shape from hemispheric to broadly convex, and has a diameter of 6 to 12 cm (2.4 to 4.7 in). The cap color is deep brown in mature specimens and lighter shades of brown in younger mushrooms. Young specimens have a sticky layer ofgluten on the cap that dries out in maturity. The edge of the cap is rolled inwards in young specimens. Theflesh of the cap is whitish and does not change color when bruised or cut. The tubes on the underside of the cap are light yellow to bright orange-yellow; the tube mouths are usually less than 1 mm wide. Thestipe is usually between 2 and 4 cm (0.8 and 1.6 in) long, less frequently reaching up to 8 cm (3.1 in). It is either the same width throughout or slightly larger (bulbous) at the base. The color of the upper portion of the stipe is pale to light yellow, while the lower portion may be light brown or covered with streaks of glutinous material like that on the cap. The stipe surface is covered with fine glands that are initially slightly darker than the color of the stipe surface, but deepen to brown or nearly black after drying. The color of thespore print was not determined from the initial collections, but is thought to be yellow-brown to brown based on the accumulated spore deposit seen on the surface of the caps of neighboring fruit bodies.[3]
The elongatespores areoblong in face view, with dimensions of 6.1–14.7 by 2.4–3.7 μm. Most spores have a single large drop of oil in them. The spore-bearing cells, thebasidia, are club-shaped, two- or four-spored, and measure 20.2–26.2 by 5.2–6.7 μm.[3]
With its short stipe and sticky cap,S. quiescens is similar toS. brevipes. It may be distinguished from the latter species by the color of the young (light-brown) cap, the glandular dots at the top of stipes in mature specimens, and the yellowish color at the top of the stipe.[3]
Fruit bodies grow together in small groups on the ground in association withbishop pine (Pinus muricata). It is the most commonSuillus species onSanta Cruz Island, itstype locality and it has also been collected atSanta Rosa Island, andPoint Reyes National Seashore in California.[3] Santa Cruz and Santa Rosa, two of the four islands that make up the northernChannel Islands, have aMediterranean climate with cool and wet winters, and warm and dry summers.[2] Most species ofSuillus do not have spores that survive in the soil for extended periods of time, but the spores ofS. quiescens can tolerate the dry conditions and heat typical of California. Another study showed that viableS. quiescens spores were present in steam-pasteurized soil planted in Oregon fields.[6] The authors suggest thatS. quiescens is an earlysuccessional 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.[3]
