ARBORETUM NEWS (NATURALISTSNOTES)

Grady Tract and Greene Prairie

SUNDAY, JUNE 26, 2011

The showiest thing on the West Knoll of the Grady Tract during Sunday’s tour was puccoon. Its brilliant orangey-yellow flower clusters can be seen from a great distance.

However, if you’re reading this a few days or a week later, that paragraph could probably be revised to read “goat’s rue”. The latter was just beginning to bloom on the 26th (by that I mean we found a total of TWO open flowers!), but at this point in the summer things happen fast.

Goat’s rue in bloom is a phenomenon not to miss. Each flower is two-toned – pink and creamy yellow. It’s in the pea family and the flowers have that typical keel-and-wings structure. There is a large patch of it very near the top of the knoll, extending on both sides of the narrow trail that runs between markers Y3 and Y4.

I hear tell that goat’s rue leaves “go to sleep” at night by twisting down to lie flat against them stem, but I confess I have not witnessed this action for myself. Since the Grady Tract closes at dusk, we will just have to take the botanists’ word for it.

But first things first … we began our Sunday stroll by admiring the elderberry bush near the entrance gate. Sambucus canadensis has just begun its blooming period; clusters of small white flowers adorn its branches.

I confess to being very fond of elderberry (though I have never made wine from its fruits). Having a soft, easily removable pith, its wood has a long history of being used to craft flutes and whistles. I carry a small wooden flute – not made from elder, but still a handmade folk instrument—with me when I hike, and at this time of year I like to pay homage to elderberry as I pass. Sunday’s tour was no exception. I played a short, simple melody standing in the shade of the bush.

Elder has many healing properties. Generally the modern medicines that are made from it are concocted from European black elder, Sambucus nigra, a close relative of our North American forms. They are sold very widely in Europe and Asia, and can be found here in pharmacies which stock herbal treatments. Depending on whose accounts you believe, elderberry either has not been found to have any significant medicinal effects – OR - relieved flu symptoms in 2 days compared to a 6-day recovery for the control group in a double-blind, placebo study! Go figure.

For this tour I took the group in the reverse order than usual, staying with the firelane trail that parallels Seminole Highway until we reached marker V1. I did this in order to point out the site of the Grady homestead at the beginning of the tour, rather than at the end. Frank Matthew Grady bought his original acreage in 1865; he and his wife, whose name I have never found in Arboretum history documents, raised eight children on the farm. None of them chose to continue in farming, and the Grady holdings (much larger by then) became University of Wisconsin property in early 1941.

We passed much tall pokeweed along the firelane. Phytolacca americana has been often discussed in our nature notes relating to the Grady Tract. It is not yet in bloom, but should be soon.

Circumnavigating the West Knoll to the west, we inspected a great many common milkweed plants, searching for Monarch butterfly eggs but finding none. A day or two previously, scouting for the tour, I had found one in that area—but I failed to mark the plant, and we couldn’t locate it on Sunday. Either we didn’t find the correct plant, or something ate the egg. Either outcome is possible.

I have seen few – nearly zero – adult Monarchs so far this summer, so I guess I shouldn’t be surprised that I have not found my usual number of eggs. Generally after the summer Solstice I am turning over the leaves of every milkweed plant I spy. You might call it my annual “egg hunt”!

A short length of wooded trail brought us to the entrance to Henry Greene’s prairie. Right now it mostly looks, well, green. Few flashy flowers are in evidence; but when you look more closely, you will be rewarded.

Some downy phlox are still colorful; pale spike lobelia’s delicate inflorescences add a note of light lavender-blue. I also noted fox sedge and, I believe, Buxbaum’s. Lead plant is in leaf but not yet in flower; ditto the blazing-stars. The humble common fleabane is much in evidence.

One of the prairie’s yellow phases (dominated by golden Alexander, prairie parsley, and yellow star-grass) is past, and the other (Silphiums and sunflowers) has not quite yet begun. But on a breezy day, the broad leaves of prairie dock will wave at you and promise the tall flower stalks soon to come.

We spotted a charming small butterfly which I am sure was a “copper” – not positive as to species. Going by the photos in Jeffrey Glassberg’s Butterflies Through Binoculars, it was likely either a Purplish or a Dorcas. Bog copper would be unlikely, as they mostly frequent cranberry bogs.

Returning up the sandy firelane to the West Knoll, we found many delights, including an interesting soil fungus. White and slightly reminiscent of coral, it was probably in the genus Tremella, but there my knowledge stops abruptly.

On a milkweed leaf near the crest of the knoll, we discovered – golden eggs! I am not making that up. They were metallic gold in color, oval, and 1-2 millimeters long; there were four of them, nearby one another, but not touching. I’m sure they’re insect eggs. Two summers ago we found similar eggs on a plant in the Native Plants Garden, watched them almost daily for weeks, and were rewarded when leaf-footed bug nymphs hatched out. I strongly suspect the ones on the West Knoll came from the same kind of critter.

Sulphur cinquefoil (Potentilla recta) is currently in bloom on the knoll and in the Greene Prairie. You can recognize it by its five pale-yellow petals and toothed, palmately compound leaves; you can distinguish it from the other species of cinquefoil by the deep notches in the petals. I did not realize it isn’t native here. Hmm, the cinquefoils are host plants for some of the Copper butterflies. How about that?? Other nearby attractions include butterfly milkweed, and a few petite sand cress flowers still winking from beneath the taller plants.

This summer there seems to be very little June grass on the West Knoll. Some years there has been quite a lot of it. Koeleria macrantha is a cool-season grass, not very tall. I find its silvery heads very attractive. I wonder if the fact that the knoll hasn’t been burned since the spring of 2008 is playing a role in its scarcity?

Needle grass, however, is prominent. Look for its long, sharp, porcupine-quill-like awns! After falling to the ground, they twist and untwist in response to changes in moisture, effectively “screwing” themselves into the soil and improving the seed’s chance to germinate.

Watch out for the poison ivy at the edges of the Grady woodland trails … but do come back soon to see what’s changed.

Located between Lake Wingra and the West Beltline Highway at 1207 Seminole Highway, the University of Wisconsin-Madison Arboretum features the restored prairies, forests and wetlands of pre-settlement Wisconsin. This 1,260-acre arboretum also houses flowering trees, shrubs and a world-famous lilac collection. Educational tours for groups and the general public, science and nature-based classes for all ages and abilities, and a wide variety of volunteer opportunities for groups, families and individuals are available.