|Taeniatherum caput-medusae (medusahead grass)|
|Entrance to the Vernal Pool section of the park|
|Medusahead with the distinctive twisting awns|
|Dense thatch of Taeniatherum caput-medusae (medusahead grass) in Phoenix Park|
|Dark depression that marks the site of the vernal pool|
|Vernal pool from several meters up.|
|Possible medusahead grass in center of vernal pool|
Imagine my surprise when I looked at the image later on my laptop and discovered that the white patch looked to be a thatch of medusahead grass!
A quick survey of the literature mentioned that this species could be found in the vicinity of vernal pools, and sometimes all the way to the high water mark of such pools. But like many other grasses, it did not seem to be able to proliferate in the pools themselves, so I am at a loss as to how this colony could thrive in this case. Perhaps there was a slight mound in that part of the pool that allowed the medusahead seedlings to take hold.
Whatever the reason, the best course of action would be to positively identify the grass, and take measures to remove these particular snakes from the park, and especially from the pools themselves. Without direct and decisive intervention, this hegemonic species might slowly take over the park, turning it into a monotypic stand of medusahead.