Friday Fabulous Flowers - SYCs

As any good field botanist knows SYCs are the birder's equivalent of LBJs (little brown jobs).  SYC stands for Stinking Yellow Composites, composites being the old irregular name for the Aster family, plants with daisy-like, dandelion-like inflorescences, which many people wrongly take as single flowers.  In the late summer and fall lots of them come into flower, especially on the prairie, and they are largely yellow.  Not the easiest group of plants to sort out accurately even for us professionals.  Here are three that TPP collected yesterday on a local prairie and with no more than 3 hours of effort using field guides, online resource, and the Flora of North America, three reasonable like 85% positive identifications were made.  All three SYCs are in the genus Helianthus, sunflowers as the name says. The trick is, which species?  At this point they would be H. grosseserratus, the sawtoothed sunflower, H. pauciflorus, the stiff sunflower, and H. tuberosus, the Jerusalem artichoke or sunchoke, which is native, no matter what the name suggest (top to bottom). The goldenrods collected at the same time were even harder.
In the bottom image you can see the ray flowers around the outside looking like petals. In the center, making the button or disk, are star-shaped flowers, all these small flowers arranged to present the image to pollinators of a big flower.