OK a couple of readers don't quite get the disk/ray flower thing that TPP mentioned in last week's FFF on goldenrod. So here is a better example, the ordinary sunflower, Helianthus annuus. This is not a flower, it is an inflorescence that mimics a flower's image. When you have little flowers, best to group them together because the bigger the display, the more visitors you get, the more pollination, and so on and so forth (my major professor always used to say that when he thought the explanation was obvious). At any rate what appear to be petals are a ring of ray flowers with one long corolla lobe making the ray flowers highly bilaterally symmetrical. They surround a spiral array of radially symmetrical disk flowers. The inner most ones are still unopened buds, so start taking a close look at those composite "flowers". Dandelions have all ray flowers, and others have nothing by disk flowers. Enjoy.
