11 November 2010

Only The Coolest Sedge In The World

You could say I'm a bit of a sedgeaholic. I've seen a lot of sedges in my time. I've gone out of my way to see certain sedges on more than one occasion, in fact. I've even pushed the limits of Lindsay's patience by staying out too late looking at sedges. It's a disease, I tell you... a downward spiral.

There is an amazing amount of morphological diversity in this graminoid family (Cyperaceae), and particularly in the multi-sectioned genus Carex, which has been divided into approximately 2000 species worldwide and almost 500 species in North America. Until this summer, Waterfall's Sedge (Carex latebracteata), a Ouachita endemic with inflated bracts that conceal the spikes, was my hands-down favorite. Others high on my list include: Golden Sedge (Carex aurea), a crowd-pleaser with tiny, orange, pumpkin-like perigynia; Ravenfoot Sedge (Carex crus-corvi), a spiky-inflorescenced gem with long-beaked perigynia that look like little golf tees; Northern Long Sedge (Carex folliculata), a charmer with inflated, gradually tapering perigynia in unique-looking spikelets; False Hop Sedge (Carex lupuliformis), an elusive yet distinct character with diamond-shaped achenes that have quite knobby angles; Painted Sedge (Carex picta), a gorgeous dioecious species with showy scales that make it a strong candidate for native landscaping; and Little Green Sedge (Carex viridula), one of the only sedges with a common name nearly as adorable as the inflorescence itself.

However, upon seeing the graceful beaut pictured above and below in Douglas County, Wisconsin this August, I could only fall to my knees and gaze appreciatively at the long awned chocolate-brown scales that much exceed the suborbicular perigynia, assembled into a pistillate spikelet somewhat reminiscent of a rattlesnake rattle. This is Boreal Bog Sedge (Carex magellanica ssp. irrigua, formerly known as Carex paupercula).

Boreal Bog Sedge, a member of Carex section Limosae, is often found with Sphagnum moss in bogs, fens, and marshes of Greenland, Canada, New England, the northern tier of Great Lakes States, a few western states, and Eurasia. The specific epithet magellanica is a reference to the Strait of Magellan, a narrow strip of water near the southern tip of South America. So how did this northern species come to be named for a southern hemisphere passageway? Carex magellanica is a bipolar disjunct species, meaning that it is found at both extremes of the globe - the northern polar regions and the southern polar regions - but not in between. Plants in the cool temperate areas of South America are known as Carex magellanica ssp. magellanica. This unique global distribution, in combination with the elegance of its inflorescence, clearly makes Carex magellanica the coolest sedge in the world.


Justin Thomas said...

Cool sedge! I don't know if it is the coolest in the world....

Thanks for the info about its distribution. Species with bipolar distributions are so fascinating. I find that I get really excited about them, but soon after become depressed by them.

But seriously, how does this type of distribution happened? Too bad there is so little work being done to answer phytogeographical questions.

Janet Creamer said...

Very cool! Love learning about this kind of stuff.

Scott Namestnik said...

Come on, Justin... what sedge is cooler than this?

There is apparently a lot of debate about bipolar disjuncts and how they occur. I can't access these articles, unfortunately, but if you can, you may want to look at Escudero, M., V. Valcárcel, P. Vargas, and M. Luceño. 2010. Bipolar disjunctions in Carex: Long-distance dispersal, vicariance or
parallel evolution? Flora. 205:2
and Moore, D.M. and O.A. Chater. 1971. Studies on bipolar species. I. Carex. Botaniska Notiser 124:317–334.

I start laughing every time I read your second paragraph, by the way.

Scott Namestnik said...

Thanks Janet. If I hadn't happened upon this sedge, I would never have learned about its crazy global distribution.

Rick said...

I have never seen C. magellanica in the wild (on my to do list). We have its close cousin Carex limisa in Ohio. Thanks for posting a sedge! Its the coolest genus in the plant kingdom!

Scott Namestnik said...

Thanks for the comment, Rick. Glad you enjoyed the post.

Actually, when I saw this plant, my initial thought was C. limosa. Good thing I collected it to run it through the keys.

beetlesinthebush said...

Thanks for the references to bipolar disjuncts - I've never heard of this phenomenon!

Sedges are way cool, as they are the primary hosts for a small group of tiny beetles that I am studying - jewel beetles in the genus Taphrocerus. A common eastern U.S. species (T. gracilis) is associated with Rhynchospora corniculata, but a way cool one to keep an eye out for is an undescribed species associated with Carex hyalinolepis. Look for the small, black, wedge shaped beetles on the foliage of plants in marginal areas (ie too sunny and dry) during June/July - if you find some and send them to me I'll be eternally grateful!

Scott Namestnik said...

No problem, Ted. I have these papers electronically... let me know if you would like me to send them to you.

I will watch for Carex hyalinolepis (which is very rare in my part of Indiana; it shows up more regularly further south of here), and if I see it I will watch for the jewel beetles you mention.

Sabatia said...

Scott, I know Justin from my time in MO, and read your blog, and Justins, often. To repay you for the delight you give me (your post on bi-polar Carex was awesome), I can send you .pdf copies of one of the articles (Escudero et al) if you like. I have access to lots of articles in my work with the US Forest Service. You might also be interested in this one "Genetic variation, taxonomy and mountain-hopping of four bipolar Carex species (Cyperaceae) analysed by AFLP fingerprinting If so, send me an email to davemoore@fs.fed.us

Thanks again and keep up the great blog. Davidl

Scott Namestnik said...

Hi Dave. I've heard your name from Justin on numerous occasions. Thanks for the great compliment on our blog, and I am glad you enjoyed the bi-polar Carex post!

I have the Escudero et al. paper, but I don't think I have the other paper you mention. I would love to have it if you can send it to me. Thanks for the offer!