Russula. Around 750 worldwide species of mushrooms compose the genus Russula and by no means are all of them edible. They are typically common, fairly large, and brightly coloured - making them one of the most recognizable genera among mycologists and mushroom collectors. Their distinguishing characteristics include a white to dark yellow spore print, brittle free white gills, and an absence of partial veil or volva tissue on the stem. Members of the related Lactarius genus have similar characteristics but emit a milky latex when their gills are broken.