Description: This native annual plant is 4-10" tall and ascending to erect, becoming abundantly branched in the upper half. Young stems are pale green to pale red and pubescent, while older stems are dark red and either glabrous or sparsely pubescent. Both young and old stems are terete (circular in cross-section). Most leaves occur in opposite pairs along the stems, although some leaves are alternate. The internodes (length between adjacent pairs of leaves) are shorter than the leaf blades. The leaf blades are ¼–¾" (6-20 mm.) long and about 1/3 as much across; they are medium green, sparsely pubescent, and oblong, elliptic-oblong, or oblanceolate-oblong in shape. The leaves are sessile, or they have short petioles. The upper surfaces of the leaves have a slightly pitted appearance. Older leaves usually wither away, causing the lower stems to become naked.
The upper stems terminate in dense short
cymes of flowers, while individual flowers may be produced on short lateral
stems below. The flowers are sessile or they have very short petioles.
Individual flowers are about 1-2 mm. long (less than 1/8"), consisting of 5
pale green lanceolate sepals, no petals, 2 stamens (rarely 3 or 5), and an
obovoid ovary with a pair of short divergent styles. The blooming period occurs
from early summer into the fall and can last 2-4 months for a colony of plants.
The flowers are probably self-fertile. Each flower is replaced by a one-seeded
utricle that is obovoid to globoid in shape, pale green to pale red, and
sparsely canescent. The utricle is about the same length as the persistent
sepals. The tiny seeds are less than 1 mm. long and they are small enough to be
blown about by the wind. The root system consists of a slender taproot. This
plant reproduces by reseeding itself.
Cultivation: The preference is partial sun,
dry-mesic to dry conditions, and soil that is rocky or sandy. This plant
tolerates little competition from other ground vegetation.
Range & Habitat: Hairy Forked Chickweed is
occasional in NE, central, and southern Illinois, becoming uncommon to absent
in other areas of the state (see
Distribution
Map). Habitats include upland rocky woodlands and rocky cliffs, upland
sandy woodlands, upland sandy savannas, sandstone glades, sandy meadows in
wooded areas, sandy paths and adjacent areas, semi-shaded edges of picnic areas
in parks, and sandy grassy areas that are infrequently mowed. Hairy Forked
Chickweed is a pioneer species that is found in areas with sparse ground
vegetation. It probably benefits from occasional wildfires, as this reduces
competition from woody plants and the accumulation of ground
debris.
Faunal Associations:
Information about floral-faunal relationships is unavailable for this species
and more field observations are desirable in this area.
Photographic Location: Along a sandy path at the
Hooper Branch Savanna Nature Preserve in Iroquois County, Illinois.
Comments: This low branching plant is easily overlooked, resembling a weed to most people who encounter it. While this species is sometimes found in disturbed areas, it also occurs in high quality natural areas. Hairy Forked Chickweed is one of two species in this genus that can be found in Illinois. The other species is Paronychia canadensis (Smooth Forked Chickweed), which has hairless stems, hairless leaves, and shorter sepals. This latter species also tends to be slightly larger in size than Hairy Forked Chickweed and its internodes are longer than its leaves. Both species are found in similar habitats, although Smooth Chickweed is less common in rocky habitats of southern Illinois. Sometimes species in this genus are referred to as 'Nailworts' because they were believed to be effective in treating an infection underneath the nails that is called 'paronychia.'