Overview shot of a large chestnut tree located just east of Reston Parkway on the south side of Bowman Green Drive, which is the circular approach to an early-to-mid 20th century mansion built for the owners of the large farming estate on which the Reston development originated in the 1960s. I believe this is a Chinese chestnut (
Castanea mollissima); more on identifying characteristics below. There is another chestnut (somewhat less grand) on the exact opposite side of Bowman Green Drive.
A colleague at work alerted me to the fact that this chestnut is now in full fruit. Compare with the
Virginia Tech fact sheet.
Once the burr-covered fruit ripen and fall from the tree, they will pop open to reveal nuts inside (the nuts here have apparently already been snacked away by the local fauna). The burrs are huge - see the keys for scale.
View of another fruit-laden branch. Note also that the undersides of the leaves are much paler than the top sides. According to
this site, this is one of the distinguishing characteristics of Chinese chestnuts as opposed to American chestnuts (
Castanea dentata).
A closer look at the underside of a leaf. Note the relative sparseness of the teeth. Note also that the very base of the leaf is rounded, so that it meets the vein at roughly right angles rather than at a much sharper angle. These, too, are characteristics of Chinese chestnuts. However, as pointed out by
this director of the New York Chapter of the American Chestnut Foundation, there has been extensive hybridization among Chinese, American, and European chestnuts over the past two centuries, so the boundaries between the species are no longer very sharp.
Two trees to the east of the chestnut tree on the south side of Bowman Green Drive is this gorgeous river birch (
Betula nigra), with its flaking red-orange bark. Compare the
Virginia Tech fact sheet. According to the key in Richard J. Preston, Jr., and Richard R. Braham,
North American Trees, 5th edition (2002), p. 170, river birch is one of only two birches that exfoliates reddish (as opposed to white) bark, and the other (yellow birch,
B. alleghaniensis) can be distinguished based on leaf shape. This type of river birch can be found on both sides of Reston Parkway (for example right outside the Macaroni Grill on the northwest corner of the intersection with New Dominion Parkway, and behind the On the Border Mexican Restaurant in the Spectrum shopping center). Although river birch is native in this area, these are clearly ornamental plantings, as Reston Parkway is on a ridge rather than in a bottomland, which is the normal setting for these birches.
Closer look at the leaves of this river birch, showing them to be untoothed and wedge-shaped at their base. Also noticeable in this photo are three green protrusions from the end of the twig. In birches, male flowers are "preformed", that is, they develop during the fall and remain on the tree throughout the winter until the female flowers emerge in the spring. I wonder whether these are the beginnings of three male catkins.
Acorns in what I believe to be a pin oak (
Quercus palustris) on the west side of Reston Parkway just north of its intersection with Bowman Towne Drive. Compare the
Virginia Tech fact sheet.
Some more acorns in this tree. The acorns are rather short and stubby, and thus are not Northern red oak (
Quercus rubra - see
Virginia Tech fact sheet). Also, the cup appears to my eyes to be saucer-shaped rather than bowl-shaped, which means it is not scarlet oak (
Quercus coccinea - see
Virginia Tech fact sheet). Pin oaks are ubiquitous in Reston.
Tall ornamental juniper shrub next to the Chevy Chase bank in the extreme southeastern corner of the Spectrum shopping center. According to Melanie Choukas-Bradley,
City of Trees, The Complete Field Guide to the Trees of Washington, D.C. (3rd ed., 2008), pp. 142-143, the juniper that is by far most commonly encountered around here is the Eastern redcedar (
Juniperus virginiana). Compare with the
Virginia Tech fact sheet.
A close-up of this juniper, with the colors somewhat bleached due to the camera flash. Note the small, closely appressed, scale-like leaves, as well as the round, blueish, berry-like cones - both of these characteristics appear consistent with this being an Eastern redcedar.
Right next to the juniper (which can be seen in the background here) is this ornamental cherry tree
(Prunus spp.). Without flowers I cannot identify the cherry more specifically. But this tree nicely shows the very distinct horizontal ringing of the bark that makes cherry trees (as a genus) easily identifiable at any time of the year. Compare this
Virginia Tech fact sheet.
A closer view of the shiny bark on a side trunk of this cherry tree. The distinct horizontal layering is caused by abundant horizontal lenticles, which are openings in the bark through which the tree can exchange water and gases.
One of a line of willow oaks (
Quercus phellos) planted along the east side of the Barnes & Noble parking lot adjoining Reston Parkway. Compare this
Virginia Tech fact sheet.
Even though the leaves are willowy-slender and not lobed like other oak leaves, this is still an oak, as can be seen by the presence of acorns (see the three hanging in the middle of this picture). Note that the acorns are very similar to those of the pin oak (
Q. palustris), but the leaf shape of course is very different.
Along the south side of Temporary Road east of Old Reston Avenue is a line of about 5 beautiful ornamental pines. They have fascicles of two long needles each, so they could be cultivars of Austrian pine (
Pinus nigra, compare
Virginia Tech fact sheet), Japanese black pine (
Pinus thunbergii, compare
Virginia Tech fact sheet), or Japanese red pine (
Pinus densiflora, compare
Virginia Tech fact sheet). I just love the triangular symmetry of cones and buds on these pines!
Close-up showing a mature cone (which has developed from the female flower) on top and the remnants of male flowers below it.
What I believe you have in this shot are green cones below, which were pollinated this past spring but have not yet been fertilized (it apparently takes a year or so for pollen inside a pine cone to actually fertilize), and new female flowers starting to bud at the top.
Further east on the south side of Temporary Road, at the very northwestern corner of the Temporary Road Recreation Area, is this common persimmon (
Diospyros virginiana) in full fruit.
Watch out when stepping underneath this tree! Once the ripe fruit has fallen (some can be seen in the grassy area), it becomes rather mushy, and when stepped on it leaves behind a big purple splotch, as seen on the sidewalk.
