Sunflowers

A few years ago I planted some seeds I had harvested from along the roadsides and now have some perennial sunflowers that are easily ten feet tall. After much effort, I think I have finally identified the species. My best guess is that they are Sawtooth Sunflowers (Helianthus grosseserratus). Unlike the cultivated sunflower, which is an annual, they come back every year and spread pretty aggressively.

 They have much smaller flowers and seeds. The insects like them, and after the flowers die, little birds come and eat the seeds.

 You cannot distinguish sunflowers by their flowers--they look too much alike. Instead the leaves and the stems are the key to identification. These have alternate leaves near the top and very smooth stems. The leaves are not highly serrated, but the Illinois wild flower page linked above says that they often are not.

 There are a lot of flowers that look like yellow daisies. The flower on the left is from the plants shown above. The one on the right has very different leaves.

 And if you turn them over, they look completely different.

I think I have finally identified the flower on the left. It is a False Sunflower (Heliopsis helianthoides). It is not even the same genus as sunflowers.

If you drive along the interstate, you can see lots of yellow flowers like these--they are late summer bloomers. There are also a lot of goldenrod plants in bloom. I have not attempted to identify goldenrod plants--there are way too many different kinds. Summer is drawing to a close, but there are still a few flowers that have not yet bloomed--my New England asters are not yet blooming.