Absinthe
Artemisia absinthium
Aster family (Asteraceae)
Description:
This herbaceous perennial plant forms
both basal leaves and erect to
ascending stems with alternate leaves; the latter are 2-4' tall,
branching occasionally. The stems are grayish green to nearly white,
densely canescent, and terete, becoming more glabrous and slightly
woody with age. Both the basal and lower alternate leaves are 2–4½"
long and ¾–1¾" across (excluding their petioles); they are bipinnatifid
to tripinnatifid. These leaves are deeply divided into primary lobes,
while their ultimate lobes are more shallow and cleft. The ultimate
lobes are 2-4 mm. across and narrowly oblong to narrowly oblanceolate
in shape, tapering abruptly into bluntly acute tips. The middle
alternate leaves are less divided and slightly smaller in size, while
the upper alternate leaves are simple or sparingly lobed and even
smaller in size. Both the upper and lower sides of the leaves are
grayish green and sparsely to moderately canescent. The basal and lower
alternate leaves have long petioles, while the middle alternate leaves
have shorter petioles, and the upper alternate leaves are sessile or
nearly so. Like the leaves, the petioles are grayish green and
canescent. The foliage of this plant has a sage-like aroma with
slightly bitter overtones. The upper stems terminate in panicles of
flowers. Along the primary rachises of these panicles, there are
primary leafy bracts at the bases of the secondary rachises; these
primary bracts are up to 1" long, linear-oblong in shape, grayish
green to nearly white, and canescent.
Secondary leafy bracts also occur
at the bases of the peduncles on the secondary rachises; these
secondary bracts are similar to the primary leafy bracts, except they
are smaller in size. Both the primary and secondary rachises of the
panicles are grayish green to nearly white and moderately to densely
canescent; they are flat or slightly concave along their upper sides
and rounded along their lower sides. The nodding flowerheads are 3-5
mm. across and 2-3 mm. tall; they are subgloboid in shape. Each
flowerhead has 20-40 perfect disk florets that are surrounded by 10-20
pistillate disk florets; both types of florets are fertile. The florets
are seperated by abundant silky hairs that originate from the
receptacle. The tiny corollas of these florets are tubular in shape and
5-lobed along their upper rims. Overall, the appearance of these
florets is yellowish brown. Along the sides of each flowerhead, there
are small appressed phyllaries (floral bracts) in several overlapping
series; these floral bracts are whitish green, densely canescent, and
oblong to ovate in shape. The flowerheads have short curved peduncles
that are whitish green and densely canescent. The blooming period
occurs from mid-summer to early autumn, lasting 2-3 weeks for a colony
of plants. The florets are cross-pollinated by the wind. Afterwards,
the florets are replaced by small achenes. Mature achenes are 0.5–1 mm.
long, narrowly oblongoid-oblanceoloid in shape, and light brown; they
lack tufts of hair. The root system consists of a taproot up to ½"
across. This plant reproduces by reseeding itself.
Cultivation:
The preference is full or partial sun,
moist to dry-mesic conditions,
and soil containing loam, clay-loam, or some gravel. The soil should be
well-drained. The size of individual plants can be highly variable
depending on their age, moisture conditions, and soil fertility. For a
herbaceous wormwood species (Artemisia), Absinthe tends to be
long-lived.
Range
& Habitat: Naturalized populations of
Absinthe can be found in NE Illinois and scattered counties elsewhere,
where it is relatively rare (see Distribution
Map). All of these
naturalized plants have escaped from cultivation. Absinthe was
introduced into North America from Europe as an ornamental and
medicinal plant. It is still cultivated occasionally in herb gardens
today. In North America, this plant is more common in the northern
plains of the United States and south-central Canada, where it is
regarded as a weed of pastures. Habitats include pastures, sunny fence
rows, gravelly areas along railroads, old homestead sites, and waste
areas. Habitats with a history of disturbance are strongly preferred.
In Illinois, Absinthe has difficulty to competing with taller native
plants in natural areas.
Faunal Associations:
Several species of
aphids are known to feed on Absinthe (Artemisia absinthium);
many
of these species originated from Europe. Examples include such species
as Coloradoa absinthii,
Coloradoa angelicae,
Coloradoa artemisiae,
Macrosiphoniella
absinthii (Absinthe Aphid), and other Macrosiphoniella
spp. (Blackman & Eastop, 2013; Robinson &
Bradley, 1965). Other insects that feed on wormwood species (Artemisia spp.)
include Aphis
middletonii(Erigeron
Root Aphid), larvae of the leaf-miner fly Calycomyza artemisiae
(Wormseed
Webworm), larvae of the Gelechiid moth, Scrobipalpula artemisiella
(Wormseed Webworm), and
larvae of the Tortricid moths Eucosma
agricolana
and Phaneta dorsiatomana
(Hottes & Frison, 1931; Spencer & Steyskal, 1986;
Marcovitch, 1916; Miller, 1987).
Some grasshoppers feed on these plants as well, including Hesperotettix viridis
(Meadow Purple-striped Grasshopper), Hypochloa alba
(Cudweed Grasshopper), and Melanoplus
angustipennis (Narrow-winged Sand Grasshopper); see
Vickery & Kevan (1985). Because
the foliage of Absinthe is aromatic and bitter, it is not preferred as
a source of food by herbivorous mammals. However, cattle and other
domesticated livestock will feed on the foliage of Absinthe if little
else is available. The consumption of a large quantity of foliage is
potentially harmful as it contains the neurotoxin, thujone.
Photographic Location:
An herb garden at Meadowbrook Park
in Urbana,
Illinois.
Comments:
Absinthe (Artemisia
absinthium) has been used to flavor an
alcoholic liquor by the same name. Excessive consumption of this liquor
has the potential to cause toxic effects and its use in some countries
has been banned. Absinthe is similar in appearance to several other
wormseed species (Artemisia
spp.); both native and non-native species
are present in Illinois. A native species that occurs in sandy areas,
Beach Wormwood (Artemisia
campestris), can be distinguished by the
longer length and narrowness of the lobes of its leaves, the sterile
florets in the center of its flowerheads, and the lack of villous hairs
on the receptacle of its flowerheads. The presence of the last
characteristic (villous hairs on the receptacles of the flowerheads)
distinguishes Absinthe from all other wormseed species in Illinois,
except for Prairie Sagebrush (Artemisia
frigida). Prairie Sagebrush has
smaller leaves with more narrow lobes (1 mm. across or less) than
Absinthe, while its flowerheads are slightly larger in size (5-6 mm.
across and 3-5 mm. tall). It is primarily a western species that is
rarely found in Illinois.