Description:
This wildflower is an annual (less often a biennial) about
4-16" tall,
branching occasionally to abundantly. The erect to ascending stems are
medium green, hairy, and terete. Alternate trifoliate leaves occur
at intervals along these stems. These leaves have short hairy petioles.
Individual leaflets are ½-1" long and about one-third as much across;
they are elliptic, elliptic-oblong, or oblanceolate-oblong in shape.
Leaflet margins are usually smooth and ciliate, although sometimes
there are tiny teeth towards their tips. The upper leaflet surface is
medium green and sparsely covered with appressed long hairs, while the
lower surface is hairy. The leaflets are sessile or nearly so. At the
base of the petiole of each compound leaf, there is a pair of stipules
about ¼" long. The green body of each stipule usually adheres to
the petiole, while its awn-like tip is detached from the petiole and it
is either green or red.
Individual flowerheads about ½-1½" long and ½"
across terminate the stems or develop from the axils of the leaves.
These flowerheads are pinkish gray with a fuzzy-hairy appearance and
they are globoid to short-cylindrical in shape. Each flowerhead has a
short peduncle that is similar to the stems. Numerous small flowers are
densely arranged along all sides and the entire length of a flowerhead.
Each flower is about ¼" in length, consisting of a white corolla
with 5 petals, a greenish-red calyx with 5 long bristly teeth, several
inserted stamens, and a pistil with a single style. The body of the
calyx is short-tubular and hairy, while the teeth are usually reddish
with white feathery hairs; these teeth extend beyond the corolla.
The narrow corolla consists of a banner (upper petal), a pair of
wings (2 lateral petals), and a small keel (2 lower petals); the banner
extends beyond the other petals and functions like a hood. The blooming
period occurs during the summer and lasts about 2-3 months. The flowers
are capable of self-fertilization in the absence of cross-pollination.
Afterwards, the flowers are replaced by small seedpods about 1/8" (3
mm.) long; they are partially hidden by the persistent calyx. Each
seedpod
contains a single seed about 1.0-1.5 mm. in length. This wildflower
reproduces by reseeding itself, often forming colonies of plants at
favorable sites.
Cultivation:
The preference is full sun,
dry-mesic conditions, and sandy soil. This wildflower may spread
aggressively in sandy disturbed areas.
Range
& Habitat: The
non-native Rabbit-Foot Clover is occasional in sandy areas of Illinois,
otherwise it is rare or absent. This species was
introduced from Eurasia. Habitats consist of upland sand prairies,
areas along railroads, sandy fields, and waste areas. Relatively open
disturbed areas are preferred where competition from other kinds of
ground vegetation has been reduced.
Faunal
Associations:
According to Müller (1873/1883) in Germany, the insect pollinators of
the flowers consist of a variety of bees, including honeybees,
bumblebees, leaf-cutting bees (
Megachile
spp.), and Halictid bees.
Small butterflies and skippers may visit the flowers to a lesser
extent. These insects suck nectar from the flowers. The remaining
information about floral-faunal relationships in
this section applies primarily to
Trifolium
spp. (clovers) in general. Many
insects feed on the foliage, stem pith, roots, or other parts of
clovers. These species include
Hypera
nigrirostris (Lesser Cloverleaf
Weevil),
Hypera punctata
(Cloverleaf Weevil),
Sitona
hispidulus (Clover
Root Weevil),
Languria
mozardi (Clover Stem Borer),
Nearctaphis bakeri
(Clover Aphid) and other aphids,
Philaenus
spumaria (Meadow
Spittlebug),
Agalliota
sanguinolenta (Clover Leafhopper),
Agalliota
quadripunctatus (Four-Spotted Leafhopper),
Sericothrips cingulatus
(thrips sp.),
Melanoplus
sanguinipes (Migratory Grasshopper) and other
grasshoppers, caterpillars of
Caenurgina crassiuscula (Clover Looper Moth) and other moths. In addition, the caterpillars of some
butterflies and skippers feed on clovers, including
Colias eurytheme
(Orange Sulfur),
Colias
philodice (Clouded Sulfur),
Everes comyntas
(Eastern Tailed Blue), and
Thorybes
pylades (Northern Cloudywing). The
Insect Table has a more complete list of insect feeders. Some
vertebrate animals also use clovers as a source of food. For example,
such upland gamebirds as the Greater Prairie Chicken and Wild Turkey
feed on the foliage and seeds, while such songbirds as the Mourning
Dove, Horned Lark, and Chipping Sparrow feed on the seeds only. The
foliage
is also eaten by some mammals: these species include rabbits,
groundhogs, deer, horses, cattle, and sheep. Because the flowerheads of
Rabbit-Foot Clover are exceptionally hairy, their consumption can
damage the health
of horses and domestic livestock by causing abdominal obstruction. In
open sandy areas, the Plains Pocket Gopher feeds on the foliage and
roots of clovers. Similarly, the Thirteen-Lined Ground Squirrel
eats their seedpods.
Photographic Location: An upland sand prairie at the
Indiana Dunes
National Lakeshore in NW Indiana.
Comments:
Rabbit-Foot Clover is easy to distinguish from other plants because of
its exceptionally hairy flowerheads and trifoliate leaves. No other
clover species (
Trifolium
sp.) in Illinois has such hairy flowerheads.
It is rather unfortunate that Rabbit-Foot Clover is not native to North
America, even though it is somewhat weedy, because its
flowerheads are quite cute and appealing.