Description:
This
perennial wildflower has fertile shoots about 1-1½' tall and
infertile shoots that are less than 1' tall. Their stems are light
green to reddish brown, terete, and pubescent to glandular-hairy. Pairs
of opposite leaves occur along these stems that are up to 2½" long and
¾" across. These leaves are medium green, narrowly lanceolate
to ovate in shape, and sparsely short-pubescent
to short-hairy. The leaf bases are sessile or they slightly
clasp their stems. The leaf tips tend to be blunt, especially those of
the infertile shoots.
The central stem of each fertile shoot terminates
in a rounded cluster of flowers about 2-3½" across. Each flower is
about 1" across, consisting of a corolla with 5 spreading lobes, a
calyx with 5 teeth, 5 inserted stamens, and a pistil. The corolla can
be light blue-violet, lavender, pink, or white and its throat consists
of a
narrow opening. The corolla base is narrowly tubular. For this
subspecies of Woodland Phlox (
Phlox
divaricata divaricata), the corolla
lobes are oblanceolate, but shallowly notched at their tips to a depth
of 1-3 mm. The sepals are light green to purple and
glandular-hairy. The teeth of sepals are linear in shape; they
extend to nearly the entire length of the sepals. The branches and
pedicels of the inflorescence are light green to purple, terete, and
glandular-hairy. The blooming period occurs from mid-spring to early
summer, lasting about 1 month. The flowers have a pleasant fragrance.
Afterwards, the flowers are replaced by ovoid seed capsules about 4 mm.
in length. Each capsule contains several small seeds. The root system
is stoloniferous, forming small clonal colonies of plants.
Cultivation: The preference is dappled sunlight to light
shade, mesic
conditions, and a rich loam with abundant organic matter. Fertile
shoots die down shortly after flowering, while infertile shoots can
retain their leaves into the winter.
Range
& Habitat: This subspecies of Woodland Phlox (
Phlox
divaricata divaricata) has not been observed in Illinois,
even though
it occurs across the border in Indiana (see
Distribution
Map).
For this
wildflower, the typical subspecies has a more eastern range, while
ssp.
laphamii has a more western range (which includes
Illinois). The ranges of these two subspecies
overlap in Indiana. It is possible, however, that isolated populations
of the typical subspecies occur in Illinois, but they have not been
reported. Habitats include rich woodlands, open woodlands, and areas
adjacent to woodland paths. In these wooded areas,
Acer saccharum
(Sugar Maple) and other deciduous trees are typically dominant.
Woodland Phlox is one of the spring wildflowers that is vulnerable to
habitat destruction and invasion of wooded areas by Garlic Mustard (
Alliaria petiolata).
Faunal Associations: The flowers of Woodland Phlox are
cross-pollinated
by bumblebees, bee flies (Bombyliidae), butterflies (especially
swallowtails), skippers, and moths (including Hummingbird Clearwing
& Sphinx moths). These insect obtain nectar from the flowers.
Other insects feed destructively on Woodland Phlox and other Phlox
species. These species include the leaf beetles
Galeruca externa
and
Scelolyperus cyanellus,
the stem-boring larvae of the long-horned
beetle
Oberea flavipes,
Lopidea davisi
(Phlox Plant Bug), and
caterpillars of such moths as
Heliothis
turbatus (Spotted Straw) and
Papaipema nebris
(Stalk Borer Moth); see Clark et al. (2004), Yanega
(1996), Knight (1941), Covell (1984/2005), and Eastman (1992) for more
information. In
addition, White-tailed Deer browse on the foliage of Woodland Phlox
sparingly.
Photographic Location: A deciduous woodland at the Pine
Hills State
Nature Preserve in west-central Indiana.
Comments:
This is another attractive wildflower that blooms during the
spring in deciduous woodlands. The typical subspecies of Woodland Phlox
(
Phlox divaricata
divaricata) is very similar in appearance to
Phlox
divaricata laphamii, except the corolla lobes of the
typical subspecies
have notched tips, while the corolla lobes of
ssp. laphamii have
rounded or bluntly angular tips. In addition, the typical
subspecies is more likely to produce pinkish flowers than
spp.
laphamii. Where their ranges overlap, it is possible to
find some
evidence of hybridization between these two subspecies.