Suillus collinitus

What You Should Know

Suillus Сollinitus occurs beneath pine trees and is most commonly found in southern European countries, particularly where large pines provide shade in otherwise dry sandy soils. This edible bolete often occurs in large groups.

Various authors regard Suillus collinitus as edible with a sour odor and nondescript taste. It is advisable, as for all species of Suillus, to pick only young specimens and to peel the cuticle before preparation.

Other names: Ringless Yellow Boletus.

Suillus collinitus Mushroom Identification

1. Pileus (Cap)

   Convex becoming flat with age, smooth and sticky, color variable from orange-brown to red-brown to brown, rounded to irregular in shape with a diameter up to 100mm.

2. Stipe

   Pale yellow with characteristic red-brown spots, short and fleshy, straight thickening slightly towards the base, with pink mycelium.

3. Pores

   Yellow without color change on bruising or cutting, angular, attached to the stipe.

4. Spore print

   Pale brown.

5. Flesh

   Yellow-colored with no color change on cutting or bruising.

6. Color Tests

   Iron sulphate - Faint blue color on cap

   Ammonia - Blue grey (cap and stipe), brown (pores)

   KOH - Blue grey (cap, fainter on stipe), brown (pores)

7. Microscopy

   Spores fusiform, smooth, 8.3-10.2µm x 3.9-4.7µm, Q=1.89-2.32, Qm=2.10

Suillus collinitus Look-Alikes

1. Suillus granulatus

   Has milky droplets beneath its young caps and white (rather than pink) mycelium at its base.

2. Suillus luteus

   Is similar in general appearance and favored habitat but it has a large white stem ring.

Suillus collinitus Medicinal Properties

The mushroom contains several tocopherols, a class of chemical compounds collectively known as vitamin E, and which confer antioxidant activity. They also contain several organic acids, most predominantly the pairs malic and quinic acids, and citric and ketoglutaric acid, which respectively make up 42% and 30% of total organic acids. The composition and concentration of organic acids in mushrooms are major factors in influencing their flavor; some organic acids contribute to antioxidant activity.

Suillus collinitus Taxonomy and Etymology

When in 1838 Elias Magnus Fries described this species he named it Boletus collinitus, and it was transferred to its current genus Suillus in 1898 by German botanist Otto Kuntze (1843 - 1907). Other synonyms for this species include Boletus collinitus Fr., and Suillus fluryi Huijsman.

In 1969 Dutch mycologist H.S.C. Huijsman described the variety S. collinitus var. aureus (as S. fluryi var. aureus; S. fluryi is a synonym of S. collinitus) based on a collection from Switzerland. The variety velatipes was described in 1998 by Giampaolo Simonini and colleagues from Italian collections.

A 1996 molecular analysis of 38 different Suillus species used the sequences of their internal transcribed spacers to infer phylogenetic relationships and clarify the taxonomy of the genus. The results indicated that S. collinitus is most closely related to a specimen of S. granuatus collected from Nepal. According to the authors, this Nepalese isolate probably represents a species distinct from North American and European isolates, based on morphology and host tree association.

In 2006, a phylogenetic analysis of Suillus isolates collected from Spain showed that S. collinitus was closely related to other species "typical of the Mediterranean area", namely Suillus bellinii, Suillus luteus, and Suillus mediterraneensis.

The British botanist Mordecai Cubitt Cooke called the mushroom the "ringless yellow boletus" in an 1873 publication.

The specific epithet collinitus is derived from Latin and means 'smeared' or 'greased', while the generic name Suillus is very straightforward, coming from the Latin noun sus, meaning pig, Suillus, therefore, means of pigs (swine) and is a reference to the greasy nature of the caps of nearly all fungi in this genus.

Sources:

Photo 1 - Author: Holger Krisp (Creative Commons Attribution 3.0 Unported)

Photo 2 - Author: tato grasso (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 3 - Author: Paffka (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 4 - Author: vesna maric (kalipso) (Creative Commons Attribution-Share Alike 3.0 Unported)