Saturday, December 29, 2012

Maracas For Mice

   I can imagine what mice do in the winter under the snow.  Perhaps they play percussion music with the square seed pods of Seedbox.  The small, hard seed capsules are filled with many small seeds and would make good mouse-sized maracas... at least if the small holes on the lid were plugged.
nearly square seedbox seed pods
    Some folks call this plant Rattle-box. Others call it Square-pod Water-primrose.  I call it Seedbox.  These are all good names for the riparian plant, Ludwigia alternifolia... as is easy to see in the photo (below) showing seeds pouring from a Seedbox's unique, squarish seed capsule.
    Later in this post, I'll show some pictures of Seedbox's four-petaled yellow flowers and also show an experiment we did with the seed capsules.
seedbox seeds also called rattle-box
  Each seed capsule has a small hole in the lid from which the seeds disperse as if from a salt shaker. squarish seed capsule of seedbox or rattle-box
 I suppose the seed dispersal happens when the plant is shaken by the wind or when jostled by passing creatures (I know I've spread some seedbox seeds just in passing). 
square seed pods of seedbox -  Ludwigia alternifolia
The small, nearly square seed capsules remain on the dead plant stalk during the winter.  There is plenty of time for windy days to do their duty of seed dispersal.
Seedbox - a winter weed
   We did a little experiment with Seedbox seed capsules.  Our hypothesis was that the seeds would be more easily shaken out of the seed pods on the branch tips and therefore emptier than seed pods farther down on the plant.  We poured out the seeds from three seed pods from each location to compare the results.
small seeds from seedbox -  Ludwigia alternifolia
   Here is a photo of the results of our experiment.  The three seed capsules on the left were from the tip of three different branches.  The three Seedbox capsules on the right were from lower down on the plant.  Compare the seed contents of the groups.
We think the reason for the lower seed content in the outermost seed pods is because they can swing more wildly in the wind and therefore more seeds were shaken out of the pod.
Oh, by the way, the seeds float.
   Seedbox likes to grow in wet areas like river banks and lake shores.  Here is a photo of a Seedbox's four-petaled yellow flower I found while on a riverside ramble.
four-petaled flower of Seedbox -  Ludwigia alternifolia
Here is a link to another site with a lovely photo of a seedbox flower.
four sepals on square fruit of seedbox
After the four petals fall off, the four sepals remain on the fruit for awhile and take on a reddish/fuchsia tinge.  
The long, thin alternating leaves also take on a bright, reddish, fall color.
Maracas in the making?
...Well, at least alot of little rattle-boxes.


  1. I am going to have to keep an eye out for this interesting plant Dana. Not sure if it is found in Nova Scotia.

    1. Sybil,
      I'm not sure that this species of seedbox grows in your area, but from the USDA website it looks like the Marsh Seedbox (Ludwigia palustris) does. The marsh seedbox is more "viney"... it grows on the ground as a mat. It has seedpods similar to this seedbox, but its leaves are not as lanceolate and are opposite rather than alternate.