Morning of August 6, 2010 (continued)

In the thicket on the south side of the W&OD bike path where it crosses the pipeline easement one can now find this bushy plant with sessile opposite leaves at its branching points and what appear to be five-petalled flowers in bloom.  This is flowering spurge (Euphorbia corollata, see this Missouri description and this Illinois article).  This plant is related to the poinsettia, and as with that species, the brightly colored structures are not petals, but rather modified leaves.

The shining or winged sumac (Rhus copallinum) is just about finished blooming, and the small seeds are beginning to set.  For how this plant will look in about six weeks, when the seeds have ripened, see this post from last September.

Another plant commonly found along the W&OD bike path that is now in the final stages of flowering:  the devil's walking stick (Aralia spinosa).  These plants have grown massively from the gnarled solitary sticks that first opened their buds in April, as seen in this post and this post.

As can be seen in this closer-up shot, the flower petals have now generally fallen away, and only the fertilized ovaries now remain that are beginning to set as fruit.

Devil's walking sticks lining both sides of the W&OD bike path, looking west from a point just west of the intersection of the bike path with Wiehle Avenue.  For how this scene will look in a couple of months, when the berries have turned black and the stalks bearing them are purple, see this post from last October;  the first picture there was taken from a point maybe 20 feet east of the photo here.

And a final shot showing sumac and devil's walking stick together in a thicket between the W&OD bike path and the W&OD gravel path just west of Wiehle Avenue.

Yet another striking plant that is now spectacularly in bloom is hollow Joe Pye weed (Eutrochium fistulosum, formerly Eupatorium fistulosum;  see this Missouri description, this Connecticut gallery, and this Wikipedia article).  This cluster is on the south side of the W&OD bike path, just east of its intersection with Isaac Newton Square and a couple hundred feet west of the devil's walking sticks shown just above.

This closer-up image shows the sagging flower heads composed of numerous tiny pink flowers that are very similar to the white-flowering thoroughworts seen in this post from last September.

The Joe Pye weeds are extremely popular with butterflies, such as the yellow swallowtail seen in this picture.  Two months ago these same butterflies were noshing on the flowers of common milkweed, as seen in this post;  remarkably, the milkweed flowers are the exact same shade of pink as the Joe Pye weed flowers.

The outcome of that earlier butterfly-noshing:  mature seedpods of common milkweed (Asclepias syriaca), taken from the same spot in the median between the W&OD bike path and the W&OD gravel path south of their intersection with Sunset Hills Road as the June flower shot referred to just above.

Hidden in the undergrowth along the south side of the W&OD bike path between Isaac Newton Square and Wiehle Avenue one can find this dainty flower with two bright blue lobes and prominent yellow false anthers.  This is Asiatic dayflower (Commelina communis, see this Missouri description);  the specific identification is enabled by the fact that it has only two rather than three blue lobes on the flower.

Finally, on the west side of the W&OD bike path just south of the Dulles Toll Road one can find this purple-flowering plant with protruding yellow anthers.  This is bittersweet nightshade (Solanum dulcamara, see this Missouri description and this Wikipedia article), which is an invasive relative of the Carolina horsenettle (featured here) and the tomato.  Note the small green fruit (quite poisonous) in the upper left corner of the image.

Morning of August 6, 2010

The western-most pond in the Fannie Mae gardens is fringed by these extremely showy plants with large leafs that float on the water and flap lazily in the wind.  Given that the leaves are entirely round, rather than bearing one deep notch, these are lotus (Nelumbo spp.) rather than water lilies.  Interspersed with the lotuses at this particular location are cattails (Typha latifolia).

Another view, which clearly shows the very characteristic seedpods left behind when the petals drop away.

Given that many of the flowers have a pinkish rather than a yellow core, these appear to be not the American lotus (Nelumbo lutea, see this Wikipedia article), but rather a hybrid with the pink Indian lotus (Nelumbo nucifera, see this Wikipedia entry).

Along the eastern edge of the pond, between the lotus pad and the shore, one can find this dense mat of aquatic plants with alternate leaves and showy five-petaled yellow flowers.  This is a form of water primrose (Ludwigia spp), and appears to be creeping water primrose (Ludwigia peploides, see this Wikipedia article and this Alabama description), which is a noxious weed.  Like other primroses, the flowers are open in the morning but have disappeared by late afternoon.

This pond, like many others in Reston, is also ringed by graceful weeping willows (Salix babylonica, see this Virginia Tech fact sheet and this Wikipedia article), an ornamental introduced from China.  In this shot, a cardinal can be spotted resting on a branch in the middle of the image.

Along the W&OD bike path, as here opposite from the Fannie Mae Gardens, one frequently encounters large patches of Japanese stiltgrass (Microstegium vimineum, see this National Park Service description and this photo gallery), which is highly invasive.  The grass superficially resembles deer-tongue grass (Dichanthelium clandestinum, compare this blog entry from a couple of months ago), but is smaller, and the leaves are less clasping of the stem.

In the broad weed-covered opening where the W&OD bike path crosses the pipeline easement, once can find this morning glory vine, whose flower is marked by five light pink splotches separated by white spokes.  This appears to be a variety of hedge bindweed (Calystegia sepium);  see the picture of a pink variety at this Missouri description.  Note also the very characteristic arrowhead-shaped leaves.  Other instances of this flower that I have seen along the W&OD path have been white rather than pink;  see, for example, this post from last October.