Sedge Heads

To know the sedges, you have to be serious. A fanatic? Perhaps not. But certainly you have to enjoy detail.

The sedges make up, by far, the region's most diverse genus. Swink and Wilhelm list 149 species of these grass-like plants (genus Carex) in the Chicago region. This contrasts with 16 species of buttercups (genus Ranunculus) and 6 blazing stars (genus Liatris).

Many of us have great affection for Somme forest preserve. Yet, our team doesn’t know the ecosystem until we can identify the plants. Facing this challenge squarely, six of us last Sunday braved heat and bugs to find and learn sedges. In the end, we found and identified 24 species. Pretty good for one morning.

The photo above wouldn't be complete without our teacher, fine citizen-scientist, John Balaban. 

Having a great teacher is an honor. John Balaban is a true "citizen scientist" - a volunteer expert. With his wife Jane, he has taught classes on subjects from trees to dragonflies to sedges - and they have the noble distinction of discovering the endangered "awnless graceful sedge" in Illinois. 

At least that's what its called in The Plants of the Chicago Region by Swink and Wilhelm. Most sources, if they give it any "common" name at all, call it "handsome sedge". Is there really a "common name" for such an obscure plant. Let's face it, no there is not. Its only real name is the scientific name, Carex formosa. "Formosa" does mean "handsome" or "beautiful." But someone who wants to learn sedges might as well learn the scientific name. At least then you can talk with botanists. 

To figure out the name of a sedge, you need a scientific "key" (a written series of choices), and the key requires you to study fine detail. Is the stem hairy? Are the seeds three sided?

One of the first sedges we found was Carex rosea. (In this case, the "common name" 

is actually helpful. It's called "curly-styled wood sedge." To tell most sedges apart you have to

look at their sexual organs. The "style" is the feathery sticking-out part of the female flower, 

the part that receives the pollen. In the case of Carex rosea, if you look close 

(through a ten-power lens), you can see that those styles make graceful curls. 

There's only one other sedge that you're likely to mistake for "curly-styled wood sedge." That's "straight-styled wood sedge" (Carex radiata). But in the field you can pretty much tell them apart by the fact that rosea stems stand up straight while radiata stems lay out flat to the sides. Perhaps they should have been called "stand-y up sedge" and "fall-y down sedge." But perhaps it's easier in the case of sedges to stick with the scientific names, that don't change from book to book. 

Some sedges are easy to recognize at a glance, like the one shown above, 

bur sedge (Carex grayi). There's nothing else that looks like it, 

at least once you get to know it a bit. 

Another one that's pretty easy is shown below. Somewhat similar, 

but the seedhead is cylindric rather than spherical.

It's called hop sedge (Carex lupulina). 

Hop sedge is named for its similarity to the hops (Humulus lupulus),
often shown on beer cans, because they're the main flavoring for beer. 

Many sedges have little clusters of little seed heads, like the one shown below, Carex tenera.

They often take a lot of study, but this one is distinctive 

because its stem takes a right-angled turn just below the seed head. 

Once we'd "learned" about twenty of these, some people's heads started to clog.

Others, those with orderly minds, seemed to thrive on the challenge.

Luckily, John Balaban, in common with God as shown on the ceiling of the Sistine Chapel, was capable of transmitting inspiration and knowledge through a single finger. 

The find of the day was the big endangered sedge shown below.

Carex tuckermanii. 

"Bent-seeded hop sedge" if you want the "common name" of this rare beauty.

The seed packets on this one are so fat that only a few can only fit around the stem.

What difference does it make if we know which sedge is which?

One answer (among many) is that, if we know where the rarities are, we can restore health 

to those habitats first. Many species are being lost in many preserves because of neglect. 

In the absence of fire, invasive species choke them out.

You could say that biodiversity is important because a long list of reasons. 

For example there are some species of butterflies that utterly depend on a few species of sedges. 

Of course, then some people will ask, who cares about butterflies?

This sort of question was raised at a contentious public hearing about whether some construction project would have to be moved - because wrecking the natural ecosystem on the site chosen would have wiped out a rare plant.

One angry citizen asked, "What good is this plant?!?"

Botany professor Hugh Iltis responded, "What good are you?"

His answer probably didn't convert many of the pro-developers. 

But he did imply a thoughtful question: What makes us think we're so important 

that we have the right to eliminate other species?

Fortunately in the North Branch Forest Preserves, there's no conflict with "progress."

The site was bought by the public decades ago 

"to protect and preserve, restore and restock the natural flora and fauna." 

The question now is, are we good stewards? 

Fortunately, learning to know, and appreciate, and take good care of the ecosystem 

is a great pleasure to many of us. It makes us happy to be generous to sedges.

A Note At The End

Below are the names of the species that we identified. 

(We still have more that we haven't keyed down yet.) 

SCIENTIFIC NAME                CC  W   COMMON NAME

Carex annectens xanthocarpa      7    0    small yellow fox sedge

Carex cephalophora                     3    3    short-headed bracted sedge

Carex crinita                               10  -5    fringed sedge

Carex crus-corvi                         10  -5    crowfoot fox sedge

Carex festucacea                         8    0    fescue oval sedge

Carex grayi                                  7   -4    common bur sedge

Carex grisea                                 2    1    wood gray sedge

Carex hirsutella                           4    5    hairy green sedge

Carex hirtifolia                            5     5    hairy wood sedge

Carex lupuliformis                    10   -5    knobbed hop sedge

Carex lupulina                             7   -5    common hop sedge

Carex muskingumensis              8   -5    swamp oval sedge

Carex pellita                                4   -5    broad-leaved woolly sedge

Carex pensylvanica                     5    5     common oak sedge

Carex radiata                               6    1     straight-styled wood sedge

Carex rosea                                  4    5     curly-styled wood sedge

Carex shortiana                          10    0     Short’s sedge

Carex sparganioides                    3    0     loose-headed bracted sedge

Carex sprengelii                          9    3     long-beaked sedge

Carex squarrosa                        10   -5     narrow-leaved cattail sedge

Carex stipata                               3   -5     common fox sedge

Carex tenera                                8    1     narrow-leaved oval sedge

Carex tuckermanii                    10   -5     bent-seeded hop sedge

Carex vulpinoidea                     2   -5    brown fox sedge 

In the list above, the "CC" is the Coefficient of Conservatism, a measure of how much a species indicates quality habitats. A "0" sedge might be found in any weed patch. But a "10" sedge would nearly always be found in a highly diverse, healthy ecosystem. 

The number under "W" indicates wetness, that is, how dependent the species is on dry habitats. A "5" species is most likely found in well-drained uplands. A "-5" species often grows in standing water. 

Acknowledgements

Thanks to John Balaban for great teaching and being a fine mentor to new stewards.

Thanks to Eriko Kojima for proofing and editing this post.

Thanks to the Cook County Forest Preserves for making a huge difference in the lives of plants, wild animals, and people.