Hurricane-Grass is Dyn-o-mite!

Hurricane-Grass is Dyn-o-Mite!

05

Nov

Fimbristylis cymosa

(Fimbristylis means fringed style. A cyme is a type of flower cluster.)

Cyperaceae, the Sedge Family

It’s not much to look at, but Hurricane-Grass is a marvel in other ways.   Few plants are tougher, cyclones cause no worries. It may worry a bit, however, about being misnamed, being a sedge not a grass. 

Hurricane-Grass flowering head

The species lives all around the hot-climate world, including remote islands from exotic South Sea adventures, usually but not always by the ocean, that is, RIGHT by the ocean, such as on wave-washed rocks, beaches, or on sand immediately interior to mangroves.   Oddly,  the populations in the New World generally have flowers with two styles, in contrast with those in the Old World having three styles.

Being a world traveler, nobody can say exactly where it is “native.” Opinions on that for Florida are mixed, with some observers regarding the plant as an invasive exotic threatening to outcompete rare native beach species in the Keys. Other highly regarded botanists perceive it to be a Florida native sharing the habitat with other indigenous species.

What’s odd is its ability to grow with no soil,  such as directly on lava in Hawaii, or on neglected old pavement such as WWII airstrips in the South Pacific, or old neglected roads in Florida.

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On asphalt in Florida. Who needs soil?

 How can that be? No soil! No nutrients!!  No water!!!  Oh the unfathomable mystery of it all!  Trying to fathom it, biologists J.  White and Q. Chen at Rutgers University examined the roots microscopically, and made a discovery:  the roots are covered with a bacterial “biofilm,” and from that film bacteria enter the root tissues.    The bacteria must have something to do with sustaining the Hurricane-Grass.  Are they nitrogen fixing?  Do they capture and process scarce nutrients?   Do they process debris captured by the plant base? Do they eat lava and asphalt?  Sadly, White & Chen did not have the sophisticated equipment required to delve into the nitty gritty.  So now they, you, I all know as much as each other.   Wouldn’t it be fun to learn the rest of the stor

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Bacteria in the root, photo by White & Chen

Part of the answer may relate to the fact that, growing on nothing, the plant builds up its own little “island” hummock of materials captured around the base.  The hummock can rise an inch above the surrounding substrate.

Related to all this, the tussock turns into a wreath with time, the center dying, maybe because the Hurricane-Grass uses up the resources at the middle. Or maybe that dead center is a natural compost bin feeding the wreath. It obviously contains goodies, because other species can tresspass in the natural “flower pot” at the wreath center, and even overwhelm and kill the Hurricane-Gra