Grassleaf Mudplantain


Heteranthera dubia
aka water stargrass


Granted, this is not the most compelling photo I’ve ever posted, nor is it the most interesting plant.  But I love it, perhaps because it’s unexpected, a bright yellow star in the muck. The common names describe it well.  This low-growing plant of wet places has long, narrow leaves that look like blades of grass.

Here’s a closer look:


It grows through most of the US except for some desert states. Technically it is an aquatic plant, but is known to survive for a time out of the water, so long as the soil is wet.  One source refers to a ‘terrestrial form’ but doesn’t go into any detail.

You’ll find this plant along the banks of the river in mid to late summer, as the water levels drop and the shoreline becomes more exposed.  What’s really neat is that in the Potomac Gorge, you can find it as much as 15 feet above above river level!  Like in the pothole that’s deliberately overexposed in the photo below, left of and slightly below the center.  I’ve been keeping an eye on it for several years now; as far as I can tell, it’s deep enough that it never dries out. Presumably it’s replenished by precipitation and the occasional flood.



The rock formation is one of the bedrock terraces the Gorge is known for.  And subject of a future post.

Flowers of the Day: Grassleaf Mudplantain and False Pimpernel

grassleaf mudplantain, aka water stargrass; Heteranthera dubia; Pontederiaceae (pickerel-weed family): 20140811-DSC_0188

false pimpernel; Lindernia dubia; Scrophulariaceae (snapdragon family): 20140811-DSC_0183

And now for something a little different – a break from the aster family of plants.  In early August, wih typical almost-droughty conditions, the river was running low, exposing mudflats, so of course I went scrambling off the trail and over the rocks to see what I could see.  And what I saw were tiny little things that are usually hidden from view.

Both of these plants are very low-growing (only a few inches tall) and like really wet soils.  Actually, grassleaf mudplantain is considered an aquatic plant.  A few days later I found it growing in a semi-permanent water hole on a bluff about 30 feet above river level:

20140814-DSC_0169(Click on the picture to see the plants on the left side of the water.)

The specific epithet “dubia”, which these plants share, means “doubtful”.  Doubtful of what, though?  Perhaps it means that the plants are atypical of their genera, as in “it looks like Lindernia, but I’m doubtful.”

False pimpernel is found across the US, except in Montana, Wyoming, and Utah.  It’s an annual that grows 4-8″ tall; the flowers measure about 1/3″ across.  On other parts of the planet it is a real pest, posing a threat to rice fields in Asia and Europe.


Grassleaf mudplantain is found everywhere in the US except Wyoming, Utah, and Nevada.  It’s of special concern in Kentucky, threatened in Maine, and endangered in New Hampshire.  The plants grow a few inches tall, with flowers a little less than an inch across. 20140814-DSC_0162





Bonus flower, to bring us back to the aster family: false daisy, Eclipta prostrata.  This was growing right alongside the other two on the muddy riverbank.