A tetragon is a quadrilateral

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There goes the math teacher again: two fancy generic names for a four-sided figure are indeed quadrilateral and, less commonly, tetragon. I bring that up only to introduce Tetragonotheca texana, a native wildflower whose buds are noticeably four-sided. Most daisy-type flowers in the sunflower family seem scentless, at least to people, but this one has a sweet fragrance, and I almost always make myself stop and smell not the roses but the nerve-ray flowers, which is one colloquial name for them; another is square-bud daisy.

I found these two nerve-ray flower heads temporarily stuck together on April 9 on the right-of-way beneath the heavy-duty power lines that cross a part of my Great Hills neighborhood in northwest Austin. The last time you saw some stuck-together flowers in these pages was about five weeks ago, when the species in contact were a Texas thistle and some prairie parsley.

In the United States this species grows only in Texas, as the species name texana truthfully tells us, and as we can see on the USDA map.

© 2012 Steven Schwartzman