Description: This native annual plant is about ½–2' tall and unbranched, except near the apex where the inflorescence occurs. The central stem is round, slender, and usually glabrous, although sometimes pubescent. There are usually sticky patches along the stem below the leaf nodes. The opposite leaves are up to 1½" long and 1/3" across. They are narrowly lanceolate, narrowly oblanceolate, or linear, with smooth margins, and are largely devoid of hairs, except near the base of each leaf along the stem.
At the apex of the plant, is a loose
cluster of flowers. A typical flower has 5 spreading petals that are notched at
their tips, and a green calyx with 10 ridges that is ovoid in shape, hairless,
and somewhat sticky. There are small triangular lobes at the top of the calyx.
A flower is up to 1/6" across, while the calyx is about 1/3" long when fully
mature. However, some varieties of Sleepy Catchfly have flowers without petals.
When petals are present, they are white, pink, or purple, and sometimes
bicolored (e.g., white on the upper side and purple on the lower side). The
blooming period occurs from late spring to mid-summer, and lasts about a month.
The flowers are diurnal, and open up in response to bright sunlight. There is
no noticeable floral scent. The small seeds are distributed to some extent by
the wind, as the slender stems sway back and forth readily. These seeds are
kidney-shaped and have a bumpy surface. The root system consists of a branching
taproot. Reproduction is entirely by seeds.
Cultivation: The preference is full sun and rather
dry conditions. Poor gravelly or cindery soil is preferred, as this reduces
competition from other plants. This plant can reseed itself readily, and is
rather weedy.
Range &
Habitat: Sleepy Catchfly occurs in most counties of Illinois and is
widely distributed (see
Distribution
Map). It is occasional to common, depending on the area. Habitats include
dry gravelly prairies, hill prairies, barrens, glades, rocky bluffs, pastures
and abandoned fields, and areas along railroads and roadsides. It is more
common in degraded, disturbed areas (particularly along railroads), but also
occurs in higher quality habitats.
Faunal
Associations: Primarily flies and small bees visit the flowers for
nectar. Flies can become stuck to the sticky surface of the calyx (at least in
some varieties of Sleepy Catchfly), while ants can become trapped in the sticky
patches of the central stem. The plant is not able to utilize nutrients from
these trapped insects, however.
Photographic
Location: The photographs were taken near an abandoned railroad in
Urbana, Illinois, on black cindery ground.
Comments: Sleepy Catchfly is a highly variable plant that is easily overlooked, except where it occurs in substantial colonies and happens to be in bloom. The plant in the photographs is the bicolored form of Sleepy Catchfly, Silene antirrhina bicolor, which is supposed to be uncommon. Plants that produce flowers without petals are referred to as Silene antirrhina apetala, while plants without sticky patches are referred to as Silene antirrhina deaneana. The plant in the upper photographs has the larger-sized flowers for Sleepy Catchfly, about 1/6" across. However, other forms with petals have flowers that span only 1/12" across. Sleepy Catchfly resembles some Stellaria spp. (Chickweeds) with grass-like leaves. However, Sleepy Catchfly has a much larger bladder-shaped calyx, as described above, and most varieties have sticky patches on the stem or calyx, which provides this species with its common name.