ARBORETUM NEWS (NATURALISTSNOTES)

Prairie in Blue and White

SUNDAY, JUNE 23, 2013

Hot and muggy are two words which could rightfully be applied to last Sunday’s weather … but that didn’t discourage our touring group of seven.

The prairie is in its blue and white color phase right now. Most of what is blooming is one of those two colors – with touches of yellow added. The latter hues are hints of what is to come; the midsummer prairie will be a gaudy one, featuring vibrant yellows and brilliant fuchsia shades.

But for right now, most of what we see is white: white wild indigo (Baptisia alba), tall beardtongue (Penstemon digitalis), yarrow (Achillea millefolia), and in some places an early bedstraw (Galium sp). Even the predominant flowering shrubs have white blossoms – gray dogwood (Cornus racemosa) and common elderberry (Sambucus canadensis(_Tradescantia ohiensis).

Spiderwort is such a fun plant! Not only does its thick, glue-y sap spin a glistening thread like spider silk; its flowers have many interesting features as well. Like lilies, each individual flower opens for one day only and then closes forever.

Spiderwort photo by Susan Carpenter

But it goes out in a blaze of glory, or at least, a smear of indigo. Crush the faded bloom between your fingers for a squirt of brilliant liquid color. (Of course, I am not recommending that hordes of people do this in the Arboretum … let your guide demonstrate, then go home and try the trick in your own garden.)

Probably my favorite of the white flowers currently in evidence is the tall beardtongue. Another of its names is ‘false foxglove’ … you may have noticed in the second paragraph above that in Latin it goes by Penstemon digitalis; true foxglove is Digitalis purpurea. Sensing a relationship here?

And digitalis, or Digoxin, is a medicine which affects the heart – a cardiac glycoside. Like all powerful cures, it is toxic in the wrong amount. It is present and potent in true foxglove … hmm … does that mean our beardtongue has it as well? Most sources say no, that the name simply reflects the plants’ similar appearance. Still, I wouldn’t test the theory.

There are many different explanations of the ‘foxglove’ name. They range from ‘fox glew’ (fox music), due to the bell-like shape of the flowers, to ‘folksgloves’, as in ‘fairy folk’. One authority even suggests that a botanist named Fuchs had something to do with it! But the ‘digit’ part is easy. All flowers in this group have long, slender flowers which would fit snugly around a finger. Gee, there’s that ‘glove’ image again.

Peering inside a beardtongue flower with a

penstemon flower

magnifying glass will reveal interesting details. (You don’t have to pluck the flower to do this, but do watch for bees!)

small bee in penstemon

For one thing, there’s a prominent fuzzy projection – it’s actually an infertile stamen – which resembles, well, a bearded tongue. The 4 other stamens curve around the back of the flower’s ‘throat’, looking for all the world like tiny rib bones. (Think of the tiniest whale skeleton imaginable.) Each of these is topped with a dark anther, whereon lies the pollen.

I said there were a few yellows, and there are. Cinquefoil, which I often call simply ‘potentilla’ for its genus name, is in considerable evidence.

Potentilla flower

Cinquefoil’s petals are a soft, lemony yellow, with 5 petals. There are 6 species present in the Arboretum, only 4 of which are native to North America: shrubby, tall, rough, and old-field. Unfortunately the species which is the showiest and most numerous—sulphur cinquefoil, with its cleft petals—is not native but rather came from Eurasia about 100 years ago. It is thoroughly naturalized at this point.

If you’re curious about that Potentilla label, it does in fact relate to the plant’s legendary medicinal and spiritual powers. In Old Europe it was considered a potent cure for many ailments, especially sores in the mouth; the root bark is said to have a styptic effect.

And speaking of 5-petaled yellow flowers currently in bloom that were said to have magical powers … St. John’s wort opened right on time again this year.

St. Johnswort

Every summer it blooms very close to June 24th, which in the Catholic tradition is the feast day of St. John the Baptist.

Like the cinquefoils, St. John’s wort comprises several species, some of which are native here and some of which are not. The genus name is Hypericum. In medieval times, the plant was thought to be a powerful medicine against witches and evil spirits; people hung it from their doors and windows to protect their households. Sensing an opportunity to turn a pagan tradition into something aligned with their own doctrine, the early Catholic Church simply ‘re-branded’ it. And you thought that practice was something new!

I have mused before about the coincidental blooming of these two plants, both with yellow flowers, both with 5 petals, both coming into flower right around the summer solstice, both with magical and/or healing properties ascribed to them. I see a potential association between the number of petals and the pentagram symbol, often linked to witchcraft; also, in the time before written calendars and clocks the solstices and the equinoxes were regarded as ‘hinges’ of the seasons, times when the boundaries between the physical and spiritual worlds were thin and permeable. A plant which comes into flower and becomes fertile at such a time might be thought of as especially significant.

As for yellow, it is the color of the Sun, clearly understood to be the source of light, heat, and life itself. Along with red, with its association with blood and vitality, I could see yellow as being a color of great intrinsic importance. Of course, then there’s green, the color of living leaves; brown, the color of the earth whose surface we walk and to which all will go in time; and blue, the color of water—so necessary to the survival of living things—and of the overarching sky.

The above are the idle musings of an amateur naturalist … take them for what they are worth. In the meantime, please enjoy our beautiful green prairie, spangled with blossoms of white, blue, and yellow.

Kathy Miner, UW Arboretum naturalist

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.