Viper's
Bugloss
Echium vulgare
Borage family (Boraginaceae)
Description:
This plant is a biennial or a short-lived perennial. It initially
consists of a low rosette of basal leaves spanning up to 1½' across,
but during the final year one or more erect to ascending stems are
produced that become 1–3¼' tall. The basal leaves are 3-9" long and
½–1¾" across; they are oblanceolate-oblong, oblanceolate-elliptic, or
oblong-elliptic in shape, while their margins are entire, ciliate with
stiff bristly hairs, and sometimes undulate (wavy up-and-down). Each
central stem is pale grayish green, terete, and densely covered with
stiff bristly hairs that have swollen purplish bases. Abundant
alternate leaves occur along each stem, becoming gradually smaller as
they ascend. These leaves are 1½–8" long, ¼–1½" across, and sessile;
they
are lanceolate-elliptic, lanceolate-oblong, or oblong-elliptic in
shape, while their margins are entire, ciliate with stiff bristly
hairs, and sometimes undulate (wavy up-and-down). The upper and lower
surfaces of both basal and alternate leaves are yellowish green or
grayish green, and they are covered with stiff bristly hairs that
sometimes have swollen white bases. Both basal and alternate leaves
have prominent central veins.
The stems terminate in inflorescences
that are ½–2' long; they consist of spike-like racemes of short
scorpioid cymes. The cymes are incurled like a
scorpion's tail, and they contain up to 20 flowers each; the sessile
flowers are arranged along only one side of the cyme. Each flower is
about ¾" across and 1" long, consisting of a deep blue or blue-violet
corolla with 5 shallow lobes, 5 grayish green sepals, 5 stamens with
reddish purple filaments, a slender white style with a divided tip, and
a 4-lobed ovary. The large corolla is campanulate (bell-shaped), but
longer above than below. The sepals are grayish green, linear-oblong in
shape, and covered with stiff bristly hairs. Both the stamens and style
are strongly exserted from the corolla. At the base of each cyme,
there is a linear-lanceolate leafy bract up to 1" long that is grayish
green and covered with stiff bristly hairs. The central stalk of the
inflorescence has the same characteristics as the central stem. The
blooming period occurs during the summer and early autumn, lasting 1-3
months. Afterwards, each flower is replaced by up to 4 nutlets (usually
only 1-2 nutlets are produced). The
nutlets are about 2.5 mm. long, grayish brown, angular-ovoid
in shape, and tuberculate (minutely bumpy). The root
system consists of a black taproot that extends up to 2½' into the
ground. This plant reproduces by reseeding itself.
Cultivation:
The preference is full sun, dry-mesic to dry conditions, and barren
soil containing limestone gravel or calcareous sand. Hot dry weather is
readily tolerated.
Range &
Habitat: Viper's Bugloss is occasional in NE
Illinois, uncommon in
east-central Illinois, and rare or absent in other parts of the state
(see Distribution
Map).
It was introduced into North America either
accidentally as a weed, or it may have been introduced deliberately as
a horticultural plant because of the showy flowers. Viper's Bugloss is
native to the Mediterranean area of Europe, and possibly
neighboring areas of Asia. Habitats include gravelly or sandy areas
along railroads, gravelly or sandy roadsides, old abandoned fields,
pastures, and waste areas. Open barren areas with a history of
disturbance are preferred.
Faunal Associations: The nectar and pollen of
the flowers attract honeybees, bumblebees, mason bees, and Halictid
bees. A mason bee, Hoplitis anthocopoides, is a
specialist pollinator of Viper's Bugloss (Echium vulgare).
In addition to these floral visitors, the Ruby-throated Hummingbird and
butterflies occasionally visit the flowers for nectar (Klemow et al.,
2002). Other insects feed destructively on the flowers and other parts
of this plant. These species include a flea beetle (Longitarsis
melanurus), a plant bug (Plagiognathus politus),
a lace bug (Dictyla echii), the Thistle Aphid (Brachycaudus
cardui), and larvae of the Viper's Bugloss Moth (Ethmiia
bipunctella);
see Clark et al. (2004), Wheeler et al. (1983), Marshall (2006), and
Blackman & Eastop (2013). Because the foliage is heavily armed
with
piercing bristly hairs and it contains toxic pyrrolizidine alkaloids,
this plant is avoided by mammalian herbivores, making it an 'increaser'
in overgrazed pastures. It is possible that the seeds are distributed
by mammalian herbivores to some extent because the bristly calyces
containing the seeds can become detached from the plant and cling to
their fur. However, most seeds fall to the ground not far from their
mother plants (Klemow et al., 2002).
Photographic Location: A sandy area near a
railroad outside of Illinois Beach State Park in NE Illinois.
Comments:
Because of its large showy flowers and exceptionally bristly foliage,
this is a very distinctive and striking plant that can't be confused
with anything else. The common name of this plant derives from its use
as a treatment for snakebites. Another common name for it is Blueweed.
While Viper's Bugloss (Echium vulgare) is considered
a
good honey plant by beekeepers, its honey may be mildly toxic from
pyrrolizidine alkaloids. These alkaloids over time can damage the liver
(Klemow et al., 2002).