Vascular Plants of the Gila Wilderness

The Asteraceae are a diverse group of flowering plants which all follow the same basic structural plan of a flower head made up of a disc of many small individual flowers. They are what most people imagine as the basic "daisy" type of flower. Most but not all of the Asteraceae will have petals, each of which really is part of an individual small flower. The Asteraceae generally have their 5 petals fused together into a floral tube, which usually remains five-lobed near the apex. The five stamens fuse together around the pistil. The seeds, attached at one point to the receptacle, are called "achenes" and are each formed by one small flower. At the end of the achene opposite the receptacle is the "pappus," which can be absent but more commonly is made up of bristles, hairs or scales. The pappus is what carries away the dandelion seeds when you blow on the flowerhead. The floral bracts at the base of the receptacle are called "phyllaries," and they may form one or many layers.