How to distinguish A. elata from the native Devil’s Walkingstick (A. spinosa) in winter? David Sibley’s guide says that A. elata is “less spiny,” but that doesn’t help very much.
Fortunately, Maraea Harris of Meadowlark Botanical Gardens pointed out for me (we were on an invasives removal work day) a cultivated example of A. elata, specifically the variety “Silver Umbrella” with variegated leaves (in the growing season, of course).
You can see that the younger stems (at left) are lightly armored, but the older trunks show only vestiges of their spines. This observation squares with a horticultural blog post from Milan Havlis.
Also of note: cultivars are grafted, and can revert to the wild type. I wonder how many of our escapes are from cultivars.
Trees and the three-lettered insects that munch on them:
To protect Eastern Hemlock (Tsuga candensis) from the Hemlock Woolly Adelgid (Adelges tsugae) (HWA), researchers are exploring natural genetic resistance, biological controls, and forestry techniques: Gabriel Popkin.
Emerald Ash Borer (Agrilus planipennis) (EAB) is clobbering native ashes (Fraxinus spp.) in the eastern U.S. Could doomed trees be turned into commercially useful building materials? Yes, say Sasa Zivkovic and Leslie Lok.
I took a break from the birds to look at some specialties of Floridian flora with Jim Stahl. We walked the grounds of the Merritt Island NWR visitor center (some of the greatest hits had interpretive signs), as well as the oak hammock trail not far from there.
We learned some quick keys for distinguishing between two very common native palms: the shrubby Saw Palmetto (Serenoa repens) and the tree-sized, covered with “boots,” Cabbage Palm (Sabal palmetto). Saw Palmetto has flat fronds and those prickles, while a Cabbage Palm leaf has a central vein that causes the leaf to form a V, and an older leaf will split along this vein. Cabbage Palm also shows brown stringy bits. On a Saw Palmetto, the fronts radiate from the distal end of the petiole, while a Cabbage Palm is costapalmate: the petiole extends farther into a midrib, forming sort of a teardrop shape.
Jim pointed out two myrsine species, Marlberry at left and “Rapanea” at right.
We saw far too many examples of the non-native invasive Brazilian Pepper (Schinus terebinthifolia), one of six species on the refuge’s hit list. The tree was in bright red fruit in January.
The heavy, ruddy streaks of sori on Swamp Fern (Blechnum serrulatum) are quite distinctive.
Florida has a very large fern with pinnae that suggest our local Christmas Fern; it’s Acrostichum danaeifolium. Perhaps now I can remember the back half of the scientific name of our fern, Polystichum acrostichoides.
Some wildflower species don’t need organics in the soil to thrive, and don’t need what we would call hospitable temperatures. Rachel Cohen of Boise State Public Radio takes a botany walk through Craters of the Moon National Monument and Preserve, which has 750 species on its checklist.
Charles Smith led the botany basics workshop at Ellanor C. Lawrence Park for Fairfax Master Naturalists. (I studied the eastern section of this park for a class in 2014.) We met a lot of old friends from the plant world. Charles pointed out a non-native invasive that I had not seen before, Small Carpetgrass (apt name, that) (Arthraxon hispidus).
In the meadow, Charles pointed out Beaked Panicgrass (Panicum anceps). I need to look at this plant a few more times before I can grok it. A tip for learning sumacs: fruits hang down from Winged Sumac.
On the west side of Walney Road, we did a very short ascent of the Ridge Trail to a patch of woods that has been left alone by White-tailed Deer. Charles describes this view a “what a good forest looks like.”
In the afternoon, Chris Ruck and his team electrofished a short reach of Big Rocky Run. Again, this was not a complete, protocol-compliant survey, but rather some cherry-picking so that we could see what species could be found in the stream. Forgive me for geeking out on the equipment, but it’s pretty cool.
A circuit is established between the anode, the pole in Danielle’s right hand, and the cathode, the cable in her right hand. Fish in the water are stunned, and can be scooped up in a net for study, as Chris is doing in the image at right. Voltage and other electrical characteristics can be adjusted for water conditions. You want rubberized waders for this job; if you’re wearing breathable waders, you will probably feel an unpleasant tingle, or worse.
Some of the catch, ready for identification.
We turned up 13 of a possible 20 species or so, according to Chris’s accounts. We spent a lot of time with the keys and the minnow representatives (family Cyprinidae). A little easier to ID were these Fantail Darters (Etheostoma flabellare) at left, and these four sunfish species (at right).
Now, the linden, it turns out, is a radical tree, as different from an oak as a woman is from a man. It’s the bee tree, the tree of peace, whose tonics and teas can cure every kind of tension and anxiety—a tree that cannot be mistaken for any other, for alone in all the catalog of a hundred thousand earthly species, its flowers and tiny hard fruit hang down from surfboard bracts whose sole perverse purpose seems to be to state its own singularity.
Elizabeth G. Knight, writing in the Bulletin of the Torrey Botanical Club, 11:11/12 (November-December 1884), p. 134:
Salisburia adiantifolia Smith. [a synonym for Ginkgo biloba] — Although it has been known for several years that the ginkgo fruits abundantly each year in Central Park, yet, as a recent copy of Henderson’s “Handbook of Plants” states, that “there has been no fruit borne in this country,” and as Josiah Hoopes in “The Book of Evergreens” does not note the fruiting of any of the trees he knows, I venture to say to all who are interested in seeing the fruit and desire to obtain specimens that they will be supplied upon application to me at the Normal College, N. Y. City.
There are 47 million birdwatchers in the U.S., but only 2.6 million waterfowl hunters. Conservation of wetlands falls disproportionately on the shoulders of hunters. And that’s a problem because hunter participation is decreasing. With fewer hunters, who’s going to pay for wildlife conservation?
Ed Yong reports on research by Jianqiang Wu of the Chinese Academy of Sciences into one of my favorite creepy plants: dodder (Cuscuta sp.). Wu’s work indicates that distinct plants parasitized by a connecting dodder vine can use it to exchange chemical signals, say, in response to herbivory.
It’s not that dodder has evolved to do this. The parasite is a generalist with unfussy taste in hosts, so it doesn’t really benefit by improving the lives of the plants it attacks. And Wu still suspects that the transmission mechanism does more harm than good, by sapping its hosts of water and nutrients. But it’s perhaps surprising that it does any good at all.