ARBORETUM NEWS (NATURALISTSNOTES)

Transitions

SUNDAY, APRIL 8, 2012

“To what purpose, April, do you return again?” asked Edna St. Vincent Millay in her poem Spring. On Sunday, if April’s purpose was to give us an enchanting hour and a half, she succeeded splendidly.

My purpose was to get the group to Big Spring in Wingra Woods to see the blooming marsh marigolds. But of course, as we angled across Longenecker Gardens toward the Wingra Woods parking lot and trailhead, we had to pause to admire the beautiful blooming collections of lilacs and flowering crabapples in the garden. Ruffles and flourishes of pink, lavender, and white are the order of the day.

We stopped to watch a male Eastern bluebird near one of the wooden birdhouses the Arboretum provides for them. He flitted up and down between a low branch and the grass. I cannot think of anything bluer than this bird’s plumage in sunlight. But of course, the color is produced by structure, not by pigment – if you ground up a bluebird’s feather, the result would be a brownish powder. It’s all about how the light strikes the surface.

From that same area we could hear, among other birdsongs, the monotonous but cheerful high-pitched trill of the chipping sparrow. These tiny birds have recently returned from their winter habitat in Texas and Mexico. They like the protective cover of conifers, and in fact that is where the song was coming from on Sunday. Look for a small brown streaky bird with a reddish cap and a dark line through its eye.

We flowed through the tall conifers toward the upper Longenecker gate, where I waited until stragglers caught up and the group reunited. Eyeing an unusually-shaped tree there, a visitor asked about it. It turned out to be a “weeping” Jack pine. Pinus banksiana is native on Wisconsin’s sandy soils, but it’s not usually seen in this particular form, with the branches trailing downward. The cultivar is called ‘Uncle Fogy’ – don’t ask me why.

Weeping or not, all Jack pines have sealed cones, which only open to release their seeds in the presence of extreme heat. No, a hot summer day is not “extreme” enough – it actually takes a fire. (You can witness this phenomenon if you place a few cones in your oven and turn up the temperature – but don’t collect the cones at the Arboretum, unless you have a research permit.) So the very fire that kills off the mature Jack pine trees ensures the species’ regeneration.

Carefully crossing the road, we entered Wingra Woods. On the right, almost immediately, there is a patch of lily-of-the-valley – a favorite in old-fashioned gardens, but considered invasive here. Yes, I know, it does have a lovely perfume.

Arboretum “regulars” know that Wingra Woods is home to an impressive group of ancient effigy mounds. Currently, the mounds are carpeted with wild-geranium foliage, making their bright-green shapes stand out vividly against the old brown leaf litter on the forest floor.

And speaking of wild geranium (Geranium maculatum) – this is the wildflower that normally bridges the spring and summer flowering seasons in the woods. It begins blooming before the true spring species have finished, but has a relatively long flowering period which extends into early summer. We found one wild geranium already in bloom on April 8th … make of that what you will.

Toothworts and crinkleroot (Cardamine concatenata and diphylla respectively) are blooming in many places in the Arboretum’s woodlands. But in Wingra Woods, and in particular along the trail leading down toward Big Spring, they grow in very close proximity to each other, making it easy for naturalists to point out the differences and similarities between the two species. The white, 4-petaled flowers are very, very similar; but toothwort has finely divided, jagged-edged leaves, while crinkleroot’s broad leaflets are grouped in threes similar to wild strawberry, and feature gently scalloped edges.

We admired patches of false rue anemone (Enemion biternatum) and troutlily (Erythronium sp) along the same trail. Although “troutlily” is the most frequently-used common name for the latter plant, I actually prefer fawnlily. Erythronium’s mottled leaves hide against the leaf litter the same way a spotted fawn is concealed in the forest. The irony? Fawnlily is probably trying to escape the attention of grazing adult deer!

At the Big Spring overlook, we feasted our eyes on the bright yellow flowers and wide rounded leaves of marsh marigolds (Caltha palustris). Someone asked if this plant is related to buttercups, and yes, it is. It is one of the several plants which has the common nickname “cow parsnip”.

Visible to the right from the railing there is a small patch of sky-blue flowers. I could not get close enough to identify them, and binoculars weren’t any help. I’m sure they aren’t wild blue phlox or Virginia bluebells. Please watch this space for an update.

Doubling back uphill, we noticed a blooming shrub which from a distance appeared to be elderberry (Sambucus canadensis). It is extraordinarily early for this plant to be in bloom, but then, as we have remarked many times, there is nothing remotely normal about the spring of 2012.

Violets, with their charming purple and white faces, are sprinkled in the grassy areas and along trail edges throughout the Arboretum. Common as this flower is, I am always delighted to see it. The name “violet” means “the tears of Io”, and comes from Greek mythology.

It seems that Io was a lovely young thing in whom Zeus, the king of the Greek gods, took an improper amount of interest. This angered his queen, Hera, who promptly turned Io into a heifer (young cow) so Zeus would not find her attractive. But the queen didn’t take away Io’s memory, so she still remembered her former life, and as she wandered about grazing in the grass she wept bitterly for what she had lost. Where the tears fell, they say, small purple flowers with heart-shaped leaves grew. And thus the name.

A few Dutchman’s breeches (Dicentra cucullaria) are hanging on in the old rock quarry near the top of the hill in Wingra Woods. This area saw a lot of treefall in the 2004 tornado, and for a time we feared the loss of wildflowers as well, but they seem to be holding their own or even increasing where the tree canopy has opened up.

Just before arriving back at the hilltop parking lot, we spied a spring first – tent caterpillars in residence on a small cherry tree. These highly social larvae, and the silky white shelters they construct, are a familiar sight for most of us; they strongly prefer cherry and apple trees. The caterpillars will live in the same “tent” for their whole lives, emerging several times a day to feed, until they metamorphose into pinkish-brown moths. The tent and their body heat en masse protect them from spring’s variable temperatures; the larvae will add more silk to the tent as they grow larger and need more space. Happy spring holidays to all!
Kathy Miner, 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.