Tuesday, March 14, 2017

Sunflower family

The Sunflower (Asteraceae) family is a large one, with many sub-divisions and groupings. (That's why I don't have a tutorial on it. Rather, I suggest that you first learn the simpler families and come back to sunflowers later or by the process of elimination.) But one thing you can say with confidence is this: if the fruit looks like a dandelion fruit (a puffy ball that you can blow away), then you are looking at a Sunflower family plant. 

All photos by Marty Horowitz 3/6/2017

Why does the fruit look like a dandelion puff, you ask? This photo of Desert Chicory (Rafinesquia neomexicana) clearly shows that each petal is actually an individual flower. (Note the reproductive parts at the base of each petal.) (The Sunflower family is also known as the Composite family, because what looks like one flower is actually composed of many flowers.)

Click on this photo to see a larger view of petals and reproductive parts. Each one of these flowers can be pollinated and thus can develop its own seed.

Silverpuffs (Uropappus lindleyi) have the same kind of structure. Click on this photo to see that there are reproductive parts at the base of each petal (which - like those of Desert Chicory - is actually composed of 5 fused petals).

To see a great example of the Silverpuffs fruit, take a look at this post from 2014.

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