Portraits of Wildflowers

Perspectives on Nature Photography

Why a four-nerve daisy is called a four-nerve daisy

with 16 comments

Click for greater clarity.

Click for greater clarity.

In a comment yesterday Joan Leacott asked why the little yellow daisy with the scientific name Tetraneuris scaposa is called a four-nerve daisy. Today’s photograph, taken like the previous one in northwest Austin on January 2 of 2012, will answer that question.

If you look at the center of the picture you’ll see that every ray is indented into three “teeth” at its tip. Each of those three teeth has two converging brown “nerves” on it. If you were to take a cross-section through those teeth you’d count six nerves. But the teeth aren’t representative of the ray as a whole, and you’ll find that each pair of nerves that flanks an indentation at the tip has grown out of a single nerve lower down on the ray. In other words, if you were to take a cross-section of a ray anywhere other than at the indentations, you’d count four nerves. Voilà, Q.E.D., case closed.

If yesterday’s photograph showed an opening bud of this species, today’s shows a more advanced stage in that opening, when the rays are better developed and already point as much outward as upward.

For more information, and to see a state-clickable map of the places in the south-central United States where Tetraneuris scaposa grows, you can visit the USDA website.

If you’re interested in photography as a craft, you’ll find that points 1, 10, 16, 19 and 23 in About My Techniques are relevant to this photograph.

© 2013 Steven Schwartzman

Written by Steve Schwartzman

January 4, 2013 at 6:17 AM

16 Responses

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  1. Ein wunderschönes Makro!!


    January 4, 2013 at 6:23 AM

  2. Beautiful shot of a this hardy little plant. I am sure you have provided this info before but are there wildflower books that you know to be the best or am I asking a ridiculous question?


    January 4, 2013 at 7:13 AM

    • Thanks. As for native plant guides, I’ve compiled a list that I’ve posted in “Books About Texas Plants,” which you can find by following the link near the top of the right-hand column on this page. By far the best for central Texas is the Enquist, which restricts itself to that region. The Ajilvsgi is a good guide for the state as a whole.

      Steve Schwartzman

      January 4, 2013 at 7:44 AM

  3. Thank you, Steve! I appreciate the effort you took to explain the curious name. There’s always a reason, isn’t there?

    Joan Leacott

    January 4, 2013 at 7:46 AM

    • You’re welcome, Joan. In this case I happened to know the answer, but in so many others I don’t. There are still plenty of things that baffle even the experts. One that comes to mind is how Phyla nodiflora came to be called frog fruit. A related question is which came first, that name or the similar fog fruit?

      Steve Schwartzman

      January 4, 2013 at 7:56 AM

  4. I was still a little curious about “nerve”. I discovered there’s a definition I didn’t know: “a prominent unbranched rib in a leaf, especially in the midrib of the leaf of a moss”. And, apparently, on rays.

    The lesson on the four nerves reminded me of the photo of the Turk’s cap, with its “string of pearls” and “sea anemones”. At the time I thought a good New Year’s resolution would be “Look more carefully”. This just reinforces the point!


    January 4, 2013 at 9:37 AM

    • Botanists have some nerve to give the word the definition you cited. I see in the 1911 Encyclopedia Britannica that the ancient Greek ancestor of the term meant “originally a sinew or tendon (and still so used in the phrase ‘to strain every nerve’), but now a term practically confined to the fibres of the nervous system in anatomy, though consequentially employed as a general psychical term in the sense of courage or firmness, and sometimes (but more usually ‘nervousness’) in the opposite sense.” And now the word has branched out into botany.

      As you know from all the macro photographs I post, I enjoy getting close to my subjects when I can. So many details would be lost to eyes—at least human eyes, and especially aging ones—that are looking from more than a few inches away. And thanks to the computer and a good monitor, I occasionally also discover something I didn’t notice at the time I took a picture, even with a macro lens.

      So much to see, so little time.

      Steve Schwartzman

      January 4, 2013 at 10:07 AM

  5. Love the photo, love the botany lesson!


    January 4, 2013 at 3:28 PM

  6. Very nice Steve. This is really spectacular.

    Brian Comeau

    January 7, 2013 at 8:50 PM

  7. Beautiful, and thanks for the explanation!


    January 14, 2013 at 2:51 PM

  8. Thanks for this explanation. I thought it might imply this plant had paralytic properties, so I’m glad you pointed me away from that crazy notion!


    May 13, 2014 at 7:17 AM

    • Based on the name alone, your notion isn’t crazy, as there’s more than one kind of nerve.

      You might say I’ve been paralyzed at times as I record the features of this wildflower, but that’s the extent of my paralysis.

      Steve Schwartzman

      May 13, 2014 at 7:44 AM

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