donkey thorn or thristle

adaptation and asteraceae being can canina characterised clasping coniferous consider convex cup donkey dreamstime dreamy each eaten edge edible effect family flowerheads flowering flushed forests genus gills herbivores inedible involucre known later leaves lepida margins mostly mushroom nature north occasionally occur parts plant plants prickles protects rim shape sharp similar stem straw subtends tasting temperate that these thistle thorn thristle trees typically when white wild yellow