Fentastic Fen June 28th

wild parsnip

Teri pointed out some nasty exotic invasives on the roadside that are definitely worth remembering. Here is wild parsnip (Pastinaca sativa). This little innocent-looking plant has invaded pretty much all of Wisconsin, and it likes all sorts of open habitats like roadsides, prairies or abandoned fields. Almost all the parts of the plant contain chemicals called furocoumarins, which with the help of ultraviolet light cause bad burns on human skin (phyto-photo dermatitis). If you get the juice on yourself, wash it off right away, and/or stay in the shade (clouds don't help, UV still comes through).
Our next candidate is honeysuckle (Lonicera spp.). Pretty much all the bushy honeysuckle species non-native, our native honeysuckles are vines, so they are easy to distinguish. Honeysuckle is one of the species that invade an area if there is no fire. Once it took over, fire is not even possible anymore, since there is no fuel. So to get rid of it, first we have to cut it down and then burn it.

honeysuckle

Moving on to buckthorns (Rhamnus cathartica - common buckthorn and Rhamnus frangula - glossy buckthorn), these shrubby plants were introduced as ornamentals, and (despite their status as a serious invasive) are still legally sold in the state for hedge rows. They form an impenetrable understory layer, which is especially bad for native, woody habitats such as oak savannas. Fire gets rid of the seedlings, but does not eradicate them, so you have to keep burning an area annually until native vegetation takes over to get rid of buckthorn. It spreads very fast, because the berries contain a laxative, and as birds eat them, well, they poop it everywhere. On the picture the branch with greener, larger leaves in the foreground is common buckthorn, and the darker green leaves in the background belong to glossy buckthorn.

buckthorns

Now that we are depressed enough of invasives, let's take a look at this wonderful fen here. Fens are one of the rarest plant communities in Wisconsin. There is a ridge passing through the landscape which provides the water pressure that feeds the fen. Walking towards the center of the fen the vegetation changes like this: tussocks - sedge meadow - (marsh) carr - fen (mound). The

shrubby cinquefoil

internal flow of groundwater is rich in calcium and magnesium bicarbonates, and sometimes calcium and magnesium sulfates as well. The calcium and magnesium bicarbonates and sulfates precipitate out at the surface (peat), creating a harsh, alkaline soil condition. Only a select group of calcium-tolerant plants, referred to as calciphiles, can tolerate these conditions. 

Chara

watercress

One of these plants, which we also referred to as an excellent community indicator, was shrubby cinquefoil (

Pentaphylloides floribunda). In the water we observed watercress (Nasturtium officinale), a  non-native edible herb, monkey flower (Mimulus ringens), Chara and cut-leaved water parsnip (Berula erecta), which is a poisonous member of the carrot family, and often grows together with watercress, so don't mix them up.

cut-leaved water parsnip

monkey flower (yellow) and watercress (white)

hard-stem bulrush

beaked spikerush

Last, as we were mounting the mound, we observed some pretty cool hard-stem bulrushes (Schoenoplectus acutus), and believed Teri that beaked spikerushes (Eleocharis rostellata)are also somewhere there, but since we didn't see them, here's a pic. Besides these, we found some native broad-leaved cattails (Typha latifolia), which is different from the exotic one, although it's not always easy to tell them apart, as they often hybridize.

broad-leaved cattail