are bright yellow in S. collinitus, cinnamon in S. variegatus and grey in S. viscidus; in shape they are round in S. luteus and angular in S. bovinus. The flesh is white to yellow in S. luteus, while it is pallid in S. variegatus with a tendency to turn blue when exposed to air. Young S. luteus and S. grevillei bear partial veils whose remnants remain as annuli hanging from the stipe; in S. granulatus the stipe is bare. S. viscidus and S. grevillei occur under larch (Larix) only, while S. sibiricus is restricted to a few species of 5-needled pine (Pinus). Habitat and distribution Species of Suillus are found all over the Northern Hemisphere where members of the tree family Pinaceae can be found. Although a few species are distributed in tropical regions (usually mountainous areas), most are limited to temperate areas. Some species have been introduced adventitiously with pine trees in pine plantations outside the natural area of Pinaceae. Some Suillus species have entered regional red lists as endangered or vulnerable. Seven European countries have listed S. sibiricus. Individual countries have also listed other species, including S. flavidus, S. tridentinus, S. collinitus, S. plorans and S. lakei. Uses Some Suillus species are edible and are highly esteemed, particularly in Slavic countries, where they are generally referred to as butter mushrooms. They are generally picked as buttons when the flesh is still firm. In some species, the slimy cap coat acts as a purgative when consumed and should be removed before cooking. Species of Suillus have been associated with the term "bolete", given to members of other genera bearing pores, most notably Boletus. Some species can be used to make mushroom dyes, like S. americanus, S. cothurnatus, S. granulatus, and S. luteus. Species , Index Fungorum lists 98 valid species of Suillus: S. abietinus S. acerbus S. acidus S. albidipes S. albivelatus (edible) S. alboflocculosus S. alkaliaurantians S. amabilis S. americanus – chicken-fat suillus S. anomalus S. appendiculatus S. bellinii S. borealis S. boudieri S. bovinoides S. bovinus – Jersey cow mushroom S. bresadolae S. brevipes – short-stalked suillus S. brunnescens S. caerulescens S. californicus S. cavipes S. cavipoides – China S. cembrae S. chiapasensis S. collarius S. collinitus S. cothurnatus S. decipiens S. flavidus (also known as S. umbonatus) S. flavogranulatus S. flavoluteus S. flavus S. furfuraceus S. fuscotomentosus S. glandulosipes S. gloeous – China S. granulatus –