Straggler daisy

When I was busy photographing frostweed doing its trick the other morning, I noticed that close to the base of one of those ice formations a straggler daisy had managed to flower, even if it looked a bit worse for wear from the cold. Known scientifically as Calyptocarpus vialis, this ground-hugging little plant produces a flower head no more than three-eighths of an inch across. Some people look down on the straggler daisy when they call it lawnflower, an alternate name based on its frequent appearance in lawns (in lieu of which, ironically, it forms an excellent native ground cover that requires little water and care).

For more information about Calyptocarpus vialis, including a map showing the states that this little species has managed to straggle its way through, you can consult the USDA website.

© 2011 Steven Schwartzman

Frostweed explains its name

Frostweed ice; click for greater detail.

In the last two posts I gave plausible reasons for the name frostweed and then I batted each one down. Today’s picture provides an answer to a question that may have occurred to you but that remained unasked: So tell us already, why is Verbesina virginica called frostweed? The name comes from one of the strangest phenomena in botany. By the time the first good frost settles overnight on the lands where this species grows, almost all of these plants have gone to seed. Although each stalk stands there unappealingly as it dries out, that first touch of hard frost can cause it to draw underground water up into its base. Now for the bizarre part: the lower part of the stalk splits as it extrudes freezing water laterally, and that process produces thin sheets of ice that curl and fold around the broken stalk and sometimes even unscroll away from it. That’s what you see in today’s picture, which I took just yesterday morning in Great Hills Park; if you’re willing to take your eyes off the pretty ice formations, you can make out a dark section of stalk in the upper left. I’ve read accounts that say some frostweed plants go through a second round of this icy phenomenon when there’s another freeze, but I’ve never tried to verify that. [Update: I’ve verified it for myself.] What I can say from experience is that the extruded sheets of ice are so light and delicate and prone to break when handled that they remind me of phyllo pastry.

And now let me answer another question that may have entered your mind. The last two posts dangled the question of frostweed’s name, but today’s picture, which explains the common name, was taken only yesterday morning. How did I know, when I began this series two days ago, that the temperature would drop enough to trigger frostweed’s ice trick and allow me to take pictures? I didn’t. I was planning to wait until the first or second week of December, which is when Austin usually gets its first hard freeze, and then take a frostweed ice picture that I’d use in an explanatory post at that time. Or if I didn’t manage to get any photographs of the phenomenon this year, I was going to show a photograph from another year. It was just serendipity that the temperature yesterday morning in Austin had dropped close enough to freezing to make some frostweed plants put on their display.

© 2011 Steven Schwartzman

Frostweed gets a visitor

Click for greater detail.

The last post provided a bud-opening view of Verbesina virginica, commonly called frostweed. Today’s picture of a slightly more advanced stage reveals a few of the fused stamen columns that are a hallmark of flowers in the sunflower family. In this species the dark-sided columns are tipped with pure white, though that’s not why the plant is known as frostweed.

But you may not be paying attention to the flowers or their name when you have such an appealing visitor. This tiny fly was only about a quarter of an inch long, and even with a 100mm macro lens I struggled to keep the main parts of it in focus. If you’d like to see more detail in the fly’s eye, which is curiously both convex and concave, the thumbnail below is an invitation. No RSVP is necessary, but the little fly and the larger I will welcome any comments that come our way.

© 2011 Steven Schwartzman

Frostweed

Frostweed; click to enlarge.

One fall-blooming species whose flowers I’m still occasionally coming across in late November is Verbesina virginica, although today’s picture goes back to October 6, when I wandered along the shaded banks of Bull Creek in my northwest part of Austin. In the stage shown here, most buds were still closed, while some had just begun to open. You may think, quite reasonably, that the common name frostweed is a reference to the white ray flowers—other species of Verbesina have yellow rays—but that isn’t why people call this plant frostweed.

To see the many places in the southeastern third of the United States where Verbesina virginica grows, you can consult the state-clickable map at the USDA website.

© 2011 Steven Schwartzman

Renaissance in yellow

In mid-September I showed a couple of early photographs of the Maximilian sunflower, Helianthus maximiliani, a species that begins blooming in late summer and continues well into the fall. In mid-October you saw a stately row of them. By last week I thought these sunflowers had pretty much played themselves out for the year, but apparently Austin’s little bit of recent rain was enough to cause a resurgence, because as Eve and I drove through far north Austin on the way to the home of some friends on Thanksgiving day, we were surprised—and happy—to see lots of new Maximilian sunflower plants springing up and flowering by the side of the road. Yesterday I went back with my camera and took pictures of those rising suns, a couple of which you now get to see as well.

When I got close to the sunflowers, I noticed that quite a few of them (though not yet those shown here) had little holes eaten out of their yellow rays, and eventually I found the likely culprits, of which you again get to see one. It’s a spotted cucumber beetle, Diabrotica undecimpunctata, whose species name tells us that this insect has one (un) plus ten (decim), which is to say eleven, spots on it.

As for Helianthus maximiliani, whose legions are numberless, it has been found growing in at least some parts of most American states and Canadian provinces. For more information, you can consult the USDA website.

© 2011 Steven Schwartzman

Stickleaf

What’s in a name? In this case, ambiguity. Mentzelia oligosperma is called stickleaf not because its leaves look like sticks, but because they stick to your clothing, flattening themselves and clinging to fabric so readily that it’s hard to get them off. The clinging nature of the leaves aside, the plant’s yellow-orange flowers are pretty, don’t you think? I photographed this one on the Brushy Creek Regional Trail in Williamson County—which was coincidentally the setting for the last two posts—on November 1.

For more information about Mentzelia oligosperma, including a state-clickable map showing the many places where the species grows, you can visit the USDA website.

© 2011 Steven Schwartzman

Lichening strikes again

Click for greater detail.

I like lichen. I was going to say that I liken lichen to nothing else, but in looking at this picture taken on the Brushy Creek Regional Trail on November 19, I have to admit that these lichen formations, especially the tan-tinted ones, look to me like fallen autumn leaves. And the tree on which this lichen was growing had fallen as well, so there’s a double connection to the season.

The punning title of today’s post is a reminder that a picture of quite a different sort of lichen appeared in these pages on October 11.

© 2011 Steven Schwartzman

Oxalis drummondii

November 19: walked east along Brushy Creek Regional Trail from Twin Lakes Park. Temperature warm, near 80°. Encountered this little wood-sorrel flower, Oxalis drummondii, in the shade. Low light, unwanted wind: what to do? Focused on the center of the flower and got the opening bud beneath it in focus as a bonus.

More species info here.

© 2011 Steven Schwartzman

Happy new

Helenium autumnale; click to enlarge.

I’ve roamed central Texas looking at native plants for a dozen years now, but the fact remains that there are more species on the plant list for Travis County that I haven’t photographed than that I have. For that reason I’m always happy to encounter something new, especially if I’m able to identify it. Walking in Bull Creek on November 17, I came across an erect plant several feet tall with flowers that looked familiar, even if the plant didn’t. The flowers were similar to those of a much lower species, Helenium amarum, called yellow bitterweed, but this plant was too tall to be that, and its leaves were different. Looking in my trusty Wildflowers of the Texas Hill Country, by Marshall Enquist, I realized that this must be the fall sneezeweed that I’d repeatedly noticed in that book but had never seen for real.

The scientific name Helenium autumnale confirms that this is indeed a species that flowers in the fall. And yes, I did spend a lot of time sneezing and blowing my nose, not because of this one plant, but more likely because of all the sumpweed and ragweed still thriving out there, and because of a high level of mold in the air; all are occupational hazards of this beleaguered nature photographer. But back to the picture: note the still-green buds in several stages of opening at the left, the freshly and fully opened flower head at the right, and the one beginning to go to seed at the left.

When I looked at the map on the USDA website, I was surprised to see fall sneezeweed shown for all the contiguous American states except New Hampshire, and for most Canadian provinces. Helenium autumnale is a relative of another sneezeweed that very early readers of this blog—which is to say almost no one—saw in its fourth post, on June 7.

© 2011 Steven Schwartzman

Flaming fruit and leaves

Flameleaf sumac; click for greater detail.

You first saw prairie flameleaf sumac, Rhus lanceolata, in this column when I interrupted an aster sequence to show you a welcome display of fall color that I ran into on November 11. On the alert for more color from this species now that I’d noticed its leaves beginning to change, three days later I went to a place along Spicewood Springs Rd. near Loop 360 where I’d photographed some of these small trees last year, and I found the scene you see here.

Flameleaf sumac is known for the varying reds that its leaflets turn in the fall, but they may first turn yellow, the color that predominates in this photograph. Like other species of Rhus, this one produces clusters of small but numerous fruits; they start out green, turn red, then dull down to gray or grayish-black. From these fruits, with ample quantities of sweetener added to mitigate the tartness, people have made sumac-ade.

For more information about Rhus lanceolata, you can visit the websites of the Lady Bird Johnson Wildflower Center and the USDA.

© 2011 Steven Schwartzman