biennial beeblossom (Gaura biennis)
Gaura biennis L.
Gaura filiformis Small
CONFIRMATION STATUS: Pending confirmation.
TAXONOMY: The currently accepted scientific name of biennial bee-
blossom is Gaura biennis L. This species is listed as Oenothera gaura in the Flora of Virginia.
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS:
Habit: Biennial beeblossom is a highly variable species with wide ranges
in plant height, leaf size, flower size, and flowering time. A native biennial
plant, herbaceous and often shrub-like, that is 4-6' when mature, branching frequently in the middle to upper half producing long flowering stems. The angular stems are covered with white hairs that are soft and long. These
hairs are more or less straight, and spread away from the stem.
Leaves: The light green leaves are about 5" long and 1½" across when
full-sized. They usually alternate along the stems, but sometimes occur in
whorls where a new stem emerges from an older stem. The leaves have
very short or no petioles, are lanceolate or ovate in shape, and have mar-
gins that are smooth or slightly dentate. Leaves have long tapering bases
and pointed tips and are hairy above and below. The leaves often turn red
during late summer or fall.
Flowers: The numerous small flowers are usually light pink, but are some-
times white or reddish pink, depending on their maturity. Flowers are 3/8”
long on a 3/16” long floral tube above a hairy 1/8” ovary. They have a
slight fragrance. There are 4 petals loosely arranged toward the top of
each flower, while 8 yellow stamens hang loosely downward. These
flowers occur on long spikes or panicles that project upward and outward
in different directions. There are tiny leaves in the inflorescence; the
flowering is rom bottom to top with only a few flowers open at one time.
Fruit/Seeds: The fruit is a spindle-shaped capsule, with four prominent
dull angles, 5/16” long and hairy. Fruits being in early July.
Roots: The root system is fibrous, while reproduction is by seed. The en-
tire plant sways with each passing breeze, thereby distributing the seeds.
REGENERATION PROCESS: Biennial beeblossom propogates itself
HABITAT TYPES: Biennial beeblossom colonizes disturbed areas in
various habitats, including mesic to dry prairies, clearings in upland wood-
lands, limestone glades, open areas, abandoned fields, miscellaneous waste
areas, and exposed gravelly banks along rivers, roadsides, and railroads.
SITE CHARACTERISTICS: Biennial beeblossom prefers full sun and
moist to dry conditions. Either clay or gravelly soil are tolerated.
SEASONAL DEVELOPMENT: The blooming period is during late
summer for about 1½ months, usually for mid-June to mid-September.
GENERAL DISTRIBUTION: Biennial beeblossom is naturally found
throughout the southeastern and mid-Atlantic states, from Georgia north
to Massachusetts, and westward through the Ohio Valley region to the
Mississippi and Missouri Rivers, into Iowa and Minnesota. It is not natur-
ally found in the southwestern, Plains,Rocky Mountain, far western or
northwestern states. It also occurs in Quebec and Ontario provinces.
SKY MEADOWS DISTRIBUTION: To be determined.
IMPORTANCE AND USES: Long-tongued bees are the primary pol-
linators, especially bumblebees. They collect pollen or suck nectar.
Moths may visit the flowers for nectar during the day or night, such as
Heliothis zea (northern corn earworm moth). Some flower moths also
visit the flowers to lay their eggs – specifically, Schinia florida (primrose
moth) and Schinia gaurae (gaura moth). Their larvae feed on the flowers
and seed capsules. The former moth often hides underneath the gaura
flowers during the day, and is well-camoflauged because of its pink color.
Various mammalian herbivores browse on this plant, such as deer and live-
Crooked Run Valley