Knotweed: Smartweed's Low-Growing Cousin

 Sitting in the sun, gravel digging into the parts of my resting on the ground, I met a new friend. I was there to see the pretty bright pink Scarlet Smartweed and its tiny insect visitors, when my eye wandered down to a nondescript, slender stem that didn't quite match its surrounding greenery. 

It sported one or two minuscule white and pink flowers at the base of the leaves (my brain insists on calling flowers located on axils like this "armpit flowers" despite the anatomical mismatch), and the shape of the flowers combined with the membrane-wrapped joints along the length of the stem were similar to the traits of my target. Was this a less-flashy relative, living comfortably in its cousin's shadow?

Fastidious gardeners and those who maintain lawns are no doubt familiar with my stringy new friend: Prostrate Knotweed (Polygonum aviculare), a common weedy plant that can often be seen spreading along sidewalk edges, forming an open flattish mat on the pavement.  It is a nonnative from Europe and, like many other widespread nonnatives, thrives in poor, compacted soil where lesser plants fear to tread. 

The leaves are not clustered in a showy inflorescence but spaced along the stem, just one or two flowers tucked in at the base each leaf.  The open flowers mostly appear white with touches of green within, while the closed flowers are a bright pink, matching the clustered flowers of the Scarlet Smartweed. 

That membranous sheath, or ochrea, a trait of the larger Polygonaceae family that includes smartweeds, docks, and even rhubarb, encloses the joints and wraps the flowers and leaf in a tidy, papery bundle at their base.  

The seeds...I shouldn't be surprised any more when researching these common weedy plants how often I find the seeds are eaten by many species of birds, including my favorite sparrows and doves.

It is one of those plants that is literally everywhere, but has gone unnoticed in my rambles simply because I had never taken the time to look! Back at my house--yep, there were those sprawling stems with rounded leaves. A hairy caterpillar happened along just as I sat down with the camera, and appeared to be nibbling near one of the flowers until a careless movement sent it disappearing into the grass. 

Though they may not be welcome in lawns among the more well-mannered flora, I can't help but admire the tenacity and the humble beauty of these hardy plants, flourishing in an unkempt mop along the sweltering pavement, unfazed by either trampling footsteps or the baking sun.