This plant is
a biennial or short-lived perennial. During the 1st
year, a rosette of basal leaves is produced. The basal leaves are up to
4" long and 3" across; they are deeply pinnatifid or bipinnatifid with
narrow linear lobes (up to 2" long and less than 3 mm. across). The
upper surface of basal leaves is grayish blue and canescent; the
petioles of these leaves are variable in length. During the 2nd and
later years (if any), this plant
bolts to become 1½-3½' tall, while the rosette of basal leaves withers
away. The central stem and ascending lateral stems are light green
to dark red and terete. Usually the young
tips of stems are tomentose (with short white cobwebby pubescence),
otherwise they are mostly glabrous. The cauline
along these stems; they are more common along the lower half of the
central stem and
lower lateral stems. The lower cauline leaves resemble the basal
leaves, except they are more green. Middle cauline leaves are
smaller in size and less divided into linear lobes, while
the upper cauline leaves are short (less than 1" long) and
in shape. The upper surface of these leaves is green to whitish
green, flat, and tomentose, becoming more glabrous with age. The lower
surface of these leaf leaves is green, rounded (convex),
and glabrous. The foliage is not strongly aromatic.
The central stem (and upper lateral stems, if any)
terminates in a panicle of flowerheads that is about 4-18" long and
about one-half as much across. Leafy linear bracts occur along the
rachis (central stalk) and lateral branches of this panicle. The
rachis and lateral branches are light green to dark red and glabrous to
canescent. The rachis of the panicle is more or less erect, while its
primary lateral branches are ascending. Individual
flowerheads are whitish green or yellowish green and 2-4 mm. long and
similarly across. Each flowerhead has 8-30 inner disk florets that
are perfect and 5-20 outer disk florets that are
pistillate. Each inner
floret consists of a narrow tubular corolla with 5 teeth along its
upper rim, some fertile stamens, and an abortive ovary that is sterile.
Each outer floret consists of a narrow tubular corolla with 2-3 teeth
along its upper rim and a fertile ovary with a divided style. The base
of each flowerhead is surrounded by appressed overlapping bracts
individual bracts are lanceolate to ovate, mostly green, and up to 2
mm. long. At maturity, the flowerheads droop from short pedicels. The
blooming period occurs from mid-summer to early autumn, lasting about
2-3 weeks. The florets are cross-pollinated primarily by the wind.
outer florets of the flowerheads are replaced by bullet-shaped achenes
that are up to 1.0 mm. in length. These achenes are without tufts of
hair or a
crown of scales; they are usually distributed only a short distance
mother plant by the wind. The root system consists of a woody
or caudex with fibrous roots. This
plant reproduces by reseeding itself.
preference is full sun, dry conditions, and sandy soil. During hot
dry periods, it is not uncommon for the lower leaves to wither away.
This plant has some tolerance to road salt.
The native Beach Wormwood is occasional in northern Illinois, and it is
also occasional in the
central section of the state along the Illinois River, otherwise it is
rare or absent (see Distribution
). Only ssp.
occurs within the state; the
typical subspecies is found in Europe. Habitats include semi-stabilized
sand dunes along Lake Michigan, dry areas of beaches, dry sand
prairies, openings in sandy savannas, rocky glades, ledges along
cliffs, sand bars and gravel bars along major rivers, abandoned sandy
fields, and sandy roadsides. Beach Wormwood prefers sandy areas where
there has been some disturbance from wind or wildfires.
To a limited extent, Beach Wormwood may be
cross-pollinated by small bees and flies seeking pollen from the
flowerheads. Other insects feed destructively on Beach Wormwood and
other wormwood species (Artemisia
). Two plant bugs, Europiella
, have been observed to feed on Beach Wormwood
specifically (Knight, 1941). Other insects that feed on wormwood
species in open areas include such grasshoppers as Hesperotettix viridis
(Snakeweed Grasshopper), Hypochlora
(Cudweed Grasshopper), and Melanoplus angustipennis
(Narrow-winged Sand Grasshopper); see Vickery & Kevan (1985).
The caterpillars of several butterflies and moths feed on the foliage
and/or flowerheads of these plants, including Vanessa cardui
(Painted Lady), Vanessa
(American Painted Lady), Scrobipalpula artemisiella
(Wormseed Webworm), Phaneta
(Tortricid moth sp.), and Protoschinia nuchalis
(Wormseed Flower Moth); see Marcovitch (1916), Marshall (2006), and
various internet websites. Several aphids (Macrosiphoniella spp.
suck plant juices from the stems, leaves, and/or flowerheads
of wormseed species (Hottes & Frison, 1931; Blackman &
Eastop, 2013). Because of the bitter taste of the foliage and its mild
toxicity, cattle and other mammalian herbivores in the
Midwestern region usually avoid consumption of Beach Wormwood and
similar species. However, vertebrate wildlife in the Western region of
the United States utilize these plants as sources of
food to a greater extent (Martin et al., 1951/1961).
Sand dunes along Lake Michigan at Indiana Dunes
State Park in NW Indiana.
Beach Wormwood is the primary host of a rare parasitic plant,
(Clustered Broomrape). The pale flowering stalk
of this parasitic plant can be observed near Beach Wormwood during late
spring or summer. A similar species, Orobanche ludoviciana
Broomrape), is also parasitic on Beach Wormwood, but this latter
species is parasitic on a variety of other species in the Asteraceae.
Among the several Artemisia
in Illinois, Beach Wormwood can be
identified by the toothless linear lobes (less than 3 mm. across) of
its deeply divided leaves. It is also unusual in
having perfect florets with sterile ovaries, which are
normally fertile in other
Another common name of Artemisia
Field Sagewort. A scientific synonym of this species is Artemisia