late goldenrod; Solidago gigantea

Canada goldenrod; Solidago canadensis

Both in the Asteraceae, of course.

Late goldenrod and Canada goldenrod grow in similar habitats.  They’re both tall (late to 7 feet, Canada to 5 feet).  They both have plume-like inflorescences and parallel-veined leaves.  Late goldenrod has slightly larger flowers than Canada goldenrod.  The main difference that I can see is in the stems: late has a slightly purplish stem (sometimes) that is (sometimes) covered with a white bloom:

while Canada goldenrod has a smooth, green stem:

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Here’s an overhead look at Canada goldenrod:

And here’s a closeup look at late goldenrod:

Tomorrow, the real culprit behind hayfever.