Martin's Woods

Martin's Woods is a state-protected natural area with very high-quality forest. It's a mix of mesic, wet-mesic and wet hardwood patches. According a highly reliable source that starts with S and ends with -teve, this is the single richest site for tree diversity in Wisconsin, with about 80 species in total.

basswood

yellow-bud hickory

black walnut

blue ash

emerald ash borer

emerald ash borer damage

Among the tree species we saw here were basswood (Tilia americana), yellow-bud hickory (Carya cordiformis), black walnut (Juglans nigra), and of course, the already familiar sugar maple (Acer saccharum).






We saw blue ash (Fraxinus quadrangulata) with its square twigs. When you dip its leaves into water, it turns the water light blue - hence the name. 
These ash trees are greatly threatened by the emerald ash borer (Agrilus planipennis), an innocent-looking but deadly beetle from Asia. The insect lays its eggs into the bark of the tree, and the larvae burrow through under the bark, destroying the tree. In a typical small town /city situation, the 4-year period, from year 8 through year 11 after infestation, will see 60 - 70% of their trees die in that region. They are calling this the curve of death because on a graph that charts time and tree death after beetle introduction, the plotted line angles almost straight up during those 4 years, ending in all the local ash trees being dead. As insects migrate, new epicenters of ash tree mortality pop up more and more frequently. These then begin to coalesce. This pattern will continue until eventually, all the ash are dead. There's no good chemical control method out there, partially because the invasion happened so quickly that there was simply no time to adequately test anything against these awful bugs. What's further devastating is that it threatens the entire Fraxinus genus, not only one species, as it would be usual. Researchers are now considering the import of some parasitoid wasps that are natural enemies to the emerald ash borer - but of course, we know the risks of bringing here yet another exotic species.

Kentucky coffeetree

We also mentioned Kentucky coffeetree (Gymnocladus dioica), a legume tree, which is often said to grow around late Native American villages, but this is not entirely true. It prefers riversides, because there it can sprout easily, and the Native Americans also frequented rivers - so they didn't move there because of the coffeetree... what a surprise. It's seeds can be used as a substitute for coffee, but in large quantitities they are toxic. This plant also offers an interesting evolutionary story: almost every part of the plant is poisonous, and other than humans, no other animal eats its fruit or seeds. The seeds are too large to be wind-dispersed, so how does is reproduce? Apparently, this plant used to rely on large mammals like mastodons for its dispersal. These swallow the seeds in whole, so the poisonous juice does not harm them, and by passing through the animal's digestive tract the seed degraded anough to germinate quickly upon exit. But mastodons and other American elephants disappeared, and the Kentucky coffeetree hasn't figured out a way to adapt yet. Fortunately, its backup system keeps is alive, the seeds can travel down in rivers, and disperse, so there's another good reason why these trees like to be near rivers. But, despite being geologically widespread, it still counts as a rare tree in Wisconsin.

jack-in-the-pulpit

wild ginger

Moving onto herbaceous plants, Martin's Woods is a wonderful place to visit in the spring to see spring ephemerals. We saw the emerging fruit of jack-in-the-pulpit (Arisaema triphyllum), the flowers of wild leek (Allium tricoccum), which has tasty underground bulbs, but the leaves are gone this time of year already. We also saw wild ginger (Asarum canadense), which has rhizomes (not roots!) that are edible, and make excellent ginger candies. And for last, a little forest-art.

tiny mushrooms growing in a black walnut shell

wild leek