Visitors to Tetraneuris scaposa

The other day you saw Tetraneuris linearifolia, one of two very similar species that share the vernacular name four-nerve daisy. Today’s picture shows the other species, Tetraneuris scaposa, and it shows that I was hardly the only one visiting it on the afternoon of February 15 in northwest Austin. If you’ve been checking this blog for a while, you’ve often heard me talk about how I sit and lie on the ground: those low vantage points reveal a lot that would go unnoticed if I were standing up and looking down at my subjects. In particular, a lot of insects hang out underneath flowers, and so do the spiders that stalk them. I’m assuming that the green insects are aphids; in addition to the two larger ones, there are several smaller ones that are harder to see. As for the spider, notice the net-like patterning on its abdomen and how long its legs are. After looking at several sources, I’m thinking that this is a spider in the genus Tetragnatha, but if anyone can be more precise, please let us know. (Update on Feb. 28: Spider Joe Lapp says that this is likely to be Tetragnatha laboriosa; from a different picture I sent him of the spider he was able to tell that it’s a male.)

As for the four-nerve daisy, if you look at the rays in the 1 o’clock and 5 o’clock positions, you can count the four “nerves” that give these flowers their common name. I don’t know what caused the reddish area on the ray at the upper right. I do know that the downiness covering the stalk and the receptacle of the flower head is a prominent characteristic of both of these Tetraneuris species (and we recently saw a similar fuzz on silverpuff, their not-so-close sunflower family relative). For more information, and to see a state-clickable map of the places where Tetraneuris scaposa grows, you can visit the USDA website.

On the technical side, it may look like I used flash for this picture, but I didn’t. Yellow is a difficult color to photograph in bright sunlight, which was the case here, and in exposing for the intense brightness of the yellow rays I ended up with a background that is close to black. For that and other photographic considerations, you can see points 1, 3, 4, 10, and 18 in About My Techniques.

© 2012 Steven Schwartzman