Counting Slender and Seaside Arrow-grass at Kish Fen

The excitement is palpable, as people say.

Awe and grandeur emerge from the numbers, if you understand and care. Fun even. 
 
Last week Pete Jackson and Lyn Campbell counted the arrow-grass plants of Kishwaukee Fen Nature Preserve. Two species. Both listed as Threatened with extinction in Illinois. These populations have never been monitored before. Kish Fen had been “an orphan” - infested with brush and weeds, but now a great bunch of Friends of Illinois Nature Preserves stewards are doing great work there. In a few years, we can monitor again and have insight into how these rare plants are doing.

 

I looked up arrow-grasses in many books, to decide what common names to use. Every book used different names. They’re just not common. They’re also not grasses. Primitive flowering plants related to bur-reeds and water plantains. 

 

Troglochin maritima - seaside arrow-grass, common bog arrow grass (common? really?), goose grass, saltmarsh arrowgrass

 

Troglochin palustris – slender arrow-grass, bog arrow grass, marsh arrowgrass

 

Arrow-grasses grow around the world but seem to be Rare or Endangered in most places. They thrive in harsh environments: salty, limy, or acid – and yet not in most such places. In the tallgrass region they live mostly in fens – but not most fen areas.  

 

Seaside arrow-grass in glorious full bloom

 

The monitoring results that Pete and Lyn filed with Plants of Concern (Chicago Botanic Garden) have given us much to think about. Some books report that the two arrow-grass species usually grow together. At Kishwaukee fen, both species occur, but they appear to shun each other. They were found in three of the four separate fens:

 

Hanging Fen 

- 0 Triglochin maritima 

- 37 Triglochin palustris

 

Marl Pools Fen

- 463 Triglochin maritima

- 1 Triglochin palustris

 

Large Raised Fen 

- 69 Triglochin maritima

- 0 Triglochin palustris

 
Pete, who has studied these species at other rare fen sites, has no explanation as to why seaside arrow-grass was the only abundant arrow grass at two of the fens while slender arrow-grass was the only one found in the hanging fen.  In addition, at the first two sites investigated, the arrow-grasses grew mostly on the edges of "marl pools" - areas where the seepage water is so limey that crystalline "tufa" rock often forms on the surface. But at the Large Raised Fen, they did not. 

Pete and Lyn also found Cladium mariscoides - the rare twig rush. (It’s not a rush, but more closely related the “saw-grass” of the Florida Everglades, which, by the way, is not a grass.) He counted 293 blooming stems - more than he'd ever seen. Rare. Obscure. Precious. 

 

Friends of Kishwaukee Fen will watch and study these plants as we seek to restore full health to the fen ecosystem. 

 

Five bonus photos

Slender bog arrow-grass blooming in Kish Fen (with some sedge seeds ripening, lower right)

 

Stewards last fall - cutting and burning brush that had shaded and killed a section of the hanging fen.

(We do this work in fall and winter. Much more is needed.)

 

Rebeccah Hartz makes a point during a stewardship planning session.

(The Fen needs experts, brain, brawn, new people. We need all.)

 

Youth steward, Allagash Rosulek, tending the fire. Friends work all year long. 

 

Kalm’s lobelia. Another rare fen species. There are so many. All lovable. 

  

Acknowledgements

 

Technical expert Pete Jackson led the monitoring of the arrow-grasses. Above and beyond being a professional, Pete has long contributed as a volunteer steward and citizen scientist. 

 

Pete’s arrow-grass monitoring colleague is Carolyn “Lyn” Campbell, who has been on the McHenry County Conservation District board and currently serves as a member of the McHenry County Board. 

 

Credit for supervising care of Kishwaukee Fen Nature Preserve goes to the Village of Lakewood and the Illinois Nature Preserves Commission. 

 

Heroes of on-the-ground stewardship are the wholehearted local volunteers of Friends of Kishwaukee Fen alongside the generous statewide volunteers of Friends of Illinois Nature Preserves.

 

The close-up arrow-grass photo is courtesy of Picfair. 

Thanks to Pete Jackson and Rebeccah Hartz for helpful edits.