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Jeepers Creepers That Sedge Has Peepers

06 Jun

Nutrushes

Scleria species

Cyperaceae (Sedges)

John and George today worked along the Haney Creek Trail near Jensen Beach, a species-rich oasis of wet pine woods, ponds, and scrub.  A dog-walkers mecca it is, and we encountered a jolly Border Collie who, being an eco-friendly pooch, retrieves pinecones.

 

Tarflower was in bloom today. Photo by John Bradford.

Tarflower was in bloom today. Photo by John Bradford.

 

There are big Sweetbay Magnolias, Dahoon Hollies with red berries, and Tarflowers abloom, all very nice, and now cast your big white eyeballs downward, and little white eyeballs in the grass return the stare.  The white of your eye is the sclera.  The white eyeball sedge is Scleria.

Peekaboo! (Scleria baldwinii by JB)

Peekaboo! (Scleria baldwinii by JB)

 

Scleria is a successful genus of some 250 species peeping from undergrowth worldwide.  Several species live natively in Florida,  and we have some uninvited exotics, too many species for individual attention.   Interested readers, if they exist, check our website floridagrasses.org.

Sedges normally make tiny seedlike fruits, called achenes, which we’ll loosely call seeds; these are brown in thousands of sedge species.  Yet one genus has adopted bright white.  What’s up with that?

Fruits and seeds are all about dispersal.  Duh. So the main point of the glossy eyeball seeds  is most likely to catch the eye.  A plant in the grassy layer is competing with many other seed-makers for creatures to ingest and disperse the seeds.  Scleria seeds are displayed prominently and stand out visually—easily spotted from afar.  Several seed-eating and ground-feeding birds eat Scleria seeds.  One example is the Bobwhite.  The tough cover (sclera is Greek for “hard”) probably helps the seed pass through the bird unscathed.

This species (S. reticularis) has a waffle pattern.

This species (S. reticularis) has a waffle pattern.

 

Part of the in-flight obstacle course is the gizzard, where some birds collect grit to grind their daily bread.  A Weaver Bird roadkilled in Africa had Scleria seeds apparently serving as gizzard stones according to Mike Bingham of the Zambian Ornithological Society.  Bingham noted also that some of the Scleria seeds seem to have been gathered not directly from the sedge plant, but from the ground where the white color may help with selection.  Bird feed suppliers sell small white Proso Millet seeds for ground-feeding birds.  The millet and Scleria are similar.

To add to the mysteries, the seeds of different Scleria species have varied surface textures: smooth, or pock-marked, waffle, or bumpy, or ribbed like a pumpkin.  Go figure.

Scleria triglomerata, dispersed by ants.  The "hypogynium" is the handy dandy ant handle at the seed base, at the left.

Scleria triglomerata, dispersed by ants. The “hypogynium” is the handy dandy ant handle at the seed base, at the left.

 

It is not just bird distribution, by the way.  One of our largest local Sclerias, S. triglomerata, has a handle called a hypogynium on the seed. (Many additional Scleria species do too.)   Ants use the hypogynium to drag the achenes to their nests, and probably eat the hypogynium away which could promote germination, as occurs in other ant-dispersed seeds.  An ant nest is a natural garden, with tilled soil, compost, and armed guards with an attitude.

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4 Comments

Posted by on June 6, 2014 in Scleria

 

Tags: ,

4 responses to “Jeepers Creepers That Sedge Has Peepers

  1. Uncle Tree

    June 7, 2014 at 7:57 am

    A “handy dandy ant handle” :) So visual, and easily imagined.
    Never thought of the ant’s nest as a garden before. How true!

    A white-eyed waffle cone is now sounding good for breakfast.
    Thanks, you two, for unusually entertaining me on this
    lazy rainy Saturday morning in the midst of many cornfields.
    :) Uncle Tree

     
  2. George Rogers

    June 7, 2014 at 12:05 pm

    Uncle Tree, What a pleasure to see you. I kinda miss cornfields, and apples, and pumpkins.

     
  3. cygnetian

    June 7, 2014 at 4:11 pm

    I just found your blog today, and you have a new subscriber! I am a fan of Florida native plants, so this is a site I will really enjoy. I found your blog after doing a search for tarflower. I found some in the woods this morning while picking wild blueberries, and I had forgotten the name of the plant. My internet search led me to this site and a wealth of info. Thanks for blogging – especially for featuring plants that are currently budding, blooming or seeding. I’ll look forward to your posts so I can compare notes with what plants are doing here in Marion County.

     
    • George Rogers

      June 7, 2014 at 4:32 pm

      So glad to see you! And glad you beat the birds to some berries. If the weather clears I’m going to go out and see some blueberries and tarflowers tonight. What a beautiful blossom! Thanks for brightening up the blog.

       

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