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.

June 22, 2010

This tall, narrow, single-stemmed plant with trifoliate compound leaves is now sprouting up like crazy along roadsides and in grassy areas.  It is a form of bush clover (Lespedeza spp.) and, based upon the pointy spike at the end of each leaflet, appears to be the highly invasive silky or Chinese bush clover (L. cuneata, for which see this Illinois description and this Missouri description).  For how this plant looks in the fall after going to seed, see this post from last October, where I misidentified it as Scotch broom, a related trifoliate legume (this did not burst into yellow flower in spring as predicted;  as a matter of fact, the plants have really emerged only in the last month or so).

This tall spindly plant with tiny white flowers can be found north of the W&OD bike path between Isaac Newton Square and the driveway for the Oak Hill Christian School.  It is white sweet clover (Melilotus albus, see this Missouri description), yet another highly invasive trifoliate legume.

At the edge of the parking lot for 1801 Robert Fulton Drive, just south of the picnic area for the W&OD bike path, is this unassuming cluster of yellow eight-rayed flowers with very wiry leaves that are whorled around the stem.  This appears to be thread-leaved tickseed (Coreopsis verticillata), for which see this Floridata record.

In the median between the W&OD bike path and the W&OD gravel path just south of Sunset Hills Road is this small meadow of gently swaying perennial ryegrass (Lolium perenne, see this Missouri description and thisOregon State treatise), just developing its inflorescence.

On the north side of the W&OD bike path just west of its intersection with Wiehle Avenue one can find this milkweed (Asclepias spp.).  It has rather narrower leaves than the common milkweed (A. syriaca) found elsewhere, and its inflorescence is at the apex of the plant, rather than hanging from its shoulders.  This appears to be swamp milkweed (A. incarnata, for which see Missouri description and this Illinois description).

The sumac (Rhus spp.) are now in bloom, as here on the north side of the W&OD bike path between Isaac Newton Square and the driveway for the Oak Hill Christian School.  This particular specimen is not the winged or shining sumac (R. copallinum) found more commonly around here (the leaf lacks the characteristic wings; compare this post from last September), but instead is smooth sumac (R. glabra, for which see this Virginia Tech fact sheet).

Further west, on the south side of the W&OD bike path just east of Old Reston Avenue, this sumac is already breaking out into fruit.  I wasn't able to quite get close enough to see what kind of sumac this is.

And finally, a nice illustration of how morning glories come by their name.  This is the same specimen of wild potato vine (Ipomoea pandurata) featured in this post from last week.  But whereas that picture was taken at 10 a.m., while the funnel-shaped flowers were at their peak opening, this picture was taken around 5 p.m. and shows the flowers rolled up against the day's heat.

Morning of March 7, 2010 (continued)

Buds ready to burst forth on a deciduous magnolia on the north side of the W&OD bike path east of Old Reston Avenue.  This is probably either a Japanese magnolia (Magnolia liliiflora) or its hybrid, the saucer magnolia (Magnolia x soulangeana), for which see this Virginia Tech fact sheet.

On the north side of the W&OD bike path, midway between American Dream Way and Isaac Newton Square, one can find a number of these tall bushes that are now bearing a profusion of catkins.  I don't know what this might be, though it quite well could be a member of the birch family, perhaps eastern hophornbeam.

Dried fruit husks on a sumac (Rhus spp.) on the south side of the W&OD bike path west of Isaac Newton Square.  For a view of sumacs in fruit last fall, see this post.

Dogbane (Apocynum spp.), with its characteristic tuning-fork-like seed pods, in the clump on the south side of the W&OD bike path just east of Wiehle Avenue that was also featured in this post.  Most of the seed pods are still closed and dried up;  only a few have opened (note the much lighter-colored leaf-like structures in the upper center of the image;  these are seed pods that have split open).

Late afternoon on September 21, 2009

Winged or shining sumac (Rhus copallina) in the weedy strip separating the parking lot for 1801 Robert Fulton Dr from the W&OD bike path.  Note the shiny wings along the petiole that joins the 11 leaflets in the compound leaf at the lower left.  For more on this species, see Virginia Tech tree factsheet.

The clusters of drupes on this sumac can get quite large.

Another shining sumac in the same strip, this one without the obvious clusters of drupes, but showing splotches of deep red fall coloration appearing.

In this particular weedy strip the pokeweed (Phytolacca americana) can get quite tall!

This strip also contains a large number of grasses, which add considerably to both the biodiversity and the beauty of this habitat.  This particular grass appears to be green foxtail (Setaria viridis), based upon its height, size and shape of panicle, drooping habit, and absence of hairs on the leaves;  see Virginia Tech weed guide.

Another view of a panicle from this grass, which is found quite frequently along this stretch of the W&OD bike path.

Mile-a-minute weed (Persicaria perfoliata) patch near the junction of the W&OD gravel path and bike path just south of the underpass under the Dulles Toll Road.  Note the distinctively shaped leaves (equilateral triangles), the round collars (ocreae) around the stem underneath some of the green fruit (especially in the lower center of the picture), and the bright blue color of the ripening fruit.  This is a highly invasive species;  see the National Park Service fact sheet.

Another view of this patch of mile-a-minute weed, with the prominent triangular leaves and a good example of an ocrea just underneath the blue fruit in the middle of the picture.  This particular patch has already climbed over some of the adjoining shrubs;  elsewhere along this stretch of the W&OD, mile-a-minute weed appears to be mostly a ground-hugging vine.

Cattail or bulrush (Typha latifolia) growing in a drainage ditch along the W&OD gravel patch underneath the Dulles Toll Road overpass.  I found this Wikipedia article on Typha to be informative.

A closer look at the distinctive cigar-shaped inflorescence of the cattail.