At the northeast corner of the small parking lot that is itself in the northeast corner of the intersection of the W&OD bike path with Old Reston Avenue is this tree with opposite pinnately compound leaves (with around 7 finely serrate leaflets) that now bears large clusters of greenish single-winged samaras. This is an ash (
Fraxinus spp.). According to the Digital Flora of Virginia, the ash species found in Fairfax County are the white ash (
F. americana, see the
Virginia Tech ID sheet), the green ash (
F. pennsylvanica, see the
Virginia Tech data sheet), and the pumpkin ash (
F. profunda, see the
Virginia Tech fact sheet). I am not yet able to decide which of these my specimen here is.
Just opposite this parking lot, as well as a bit further east on the south side of the W&OD bike path, one finds this plant that is now profusely orange-flowering, with the cup-shaped flower having a distinct spur that almost gives it the appearance of being an old-fashioned pipehead. The leaves are broadly serrate (the triangular leaves in this image belong to mile-a-minute vine, which is a noxious weed infesting the entire W&OD bike path roadside in Reston).
Another image of this plant, giving a better view of the leaf with its distinctive serration. This is orange jewelweed (
Impatiens capensis, see this
Illinois description and this
Missouri description). I guess I'll have to look out for the seeds to appear and then test whether they in fact eject explosively when touched!
All along the southern edge of the W&OD bike path east of Old Reston Avenue the ragweeds (
Ambrosia spp.) are in full bloom, ready to release the pollen that is such a bane for allergy sufferers.
This particular specimen has unlobed to trilobed leaves, as seen here, which, together with its substantial height (the racemes extend above my height), makes this giant ragweed (
Ambrosia trifida, compare this
Illinois description and this
Missouri description).
A bit further east along the W&OD bike path is this specimen, whose flowers are already tinged yellow and thus just about ready to release their pollen. The leaves on this specimen are pinnately lobed, but not quite bipinnately compound, which suggests that this is western ragweed (
Ambrosia psilostachya, see this
Texas description) rather than common ragweed (
A. artemisiifolia, see this
Virginia Tech weed description and this
Illinois description), which I also saw today but failed to photograph.
The silky or Chinese bush clover (
Lespedeza cuneata) is now in bloom, bearing small white flowers that look much like pea flowers (understandable given that, like peas, vetches, black locusts, wisteria, and other clovers, this is a legume). For how the bush clover looked a couple of months ago as it first emerged from the ground, see this
post from June; for how it will look in a month once it bears its fruit, see this
post from last October.
Another legume that is now profusely blooming (purplish-pink rather than white), as seen here on the south side of the W&OD bike path just west of Isaac Newton Square, is the tick clover (
Desmodium spp.).
A closer look at some of the tick clover flowers. In the lower right corner of the image, one can also see some fruit, which in this genus typically is in the form of four seeds that are individually encapsulated along a string rather than contained in a pod. For some descriptions of tick clover, see this
Missouri description and this
Illinois description. There are quite a few species of this genus found in Fairfax County, and they are difficult to tell apart, so I cannot provide specific identification for this plant.
One more legume, this one in tree form. This honeylocust (
Gleditsia triacanthos, see this
Virginia Tech fact sheet) is located on the southern edge of the Pizza Hut parking lot adjoining the W&OD gravel path just east of its intersection with Wiehle Avenue. One can easily see the pinnately compound leaves with dozens of small roundish leaflets that are typical of legumes (for example vetches or black locusts). Looking closer (especially near the right edge of the image) one can also see the twisted remnants of large seed pods. The resilient honeylocust is a popular ornamental tree for parking lots and other highly polluted areas (such as the parking lots for Plazamerica and for the Spectrum Center); most of the ornamental honeylocusts planted now are sterile, but this one is not and thus actually produced seed.
