This is a
perennial wildflower about 1½-3½' tall that branches occasionally. The
stems are light green, red, brown, or nearly white; they are terete and
glabrous (except for an uncommon variety with pubescent stems). The
alternate leaves are 1¼-4" long and ¼-¾" across; they are
narrowly lanceolate or elliptic, smooth along their margins; sometimes
their margins are slightly ciliate or they are tinted red. The leaves
are light to medium green and glabrous (except for an uncommon variety
with pubescent leaves). The leaves are sessile or they have short
petioles (less than ½" in length). Leaf venation is pinnate.
upper half of each plant, solitary flowers develop from the axils of
the leaves on short pedicels (about 1/8" in length). Each flower is
½-¾" across, consisting of 4 yellow petals, 4 light green sepals, 4
short stamens, and a pistil with a short style. The tip of the style is
light green and globular. The petals are oval to obovate in shape,
while the sepals are ovate-cordate in shape; both petals and sepals are
about the same length. The sepals are glabrous and smooth along their
margins; sometimes their margins are slightly ciliate or tinted red.
The blooming period occurs during the summer for about 2 months. Each
flower remains intact for only a single day; the petals are
early-deciduous and become detached when they are exposed to even minor
disturbance. Later in the year, the flowers are replaced
capsules (about ¼" in length) with a cubic shape that turn brown at
maturity. The tiny seeds
are released from each capsule by a small pore at its apex. These
can float on water or be blown about by the wind, distributing the
seeds to new areas. Individual seeds are 0.5-1.0 mm. in length and
narrowly ellipsoid in shape. The root system is fleshy and fibrous.
The preference is full to partial sun, wet to moist conditions, and an
acidic sandy soil, although other soil types are tolerated.
The native Seedbox is occasional in
most areas of
Illinois, except in parts of central and northern Illinois, where it is
either uncommon, rare, or absent. Habitats
include openings in floodplain woodlands, sandy swamps, acidic gravelly
seeps, low areas along streams and ponds, wet prairies, wet
sand prairies, and roadside ditches. The pubescent variety of Seedbox,
, occurs in southern Illinois, where it
According to Robertson (1929), the flowers
of Seedbox are
visited primarily by bees, including Halictid bees (Augochlorella spp.
) and leaf-cutting bees
the bees suck nectar or collect pollen from the
flowers. Less common floral visitors include Sphecid wasps, small
butterflies, beetles, and other insects. Some insects also feed on the
foliage and other parts of Seedbox. These species include the leaf
beetle Colaspis suggona
the flea beetle Altica
caterpillars of the moth Eudryas
(Pearly Wood Nymph). White-Tailed
Deer occasionally browse on the foliage during the summer.
Edge of a sandy swamp at the Heron Boardwalk in
Seedbox has showier flowers than most Ludwigia spp.
its cubic seed
capsules have a distinct appearance. As a result, it is fairly easily
to identify when either the flowers or seed capsules are present.
Species in this genus are usually found in wetlands. Species in a
related genus of the Evening Primrose family, Epilobium spp.
(Willow-Herbs), have similar foliage and prefer similar habitats. They
can be distinguished from Ludwigia
by their narrowly cylindrical
seedpods and the presence of tufts of hair on their seeds.