Valerian family (Valerianaceae)
Description: This wildflower is a winter or spring annual about 1-3' tall. Initially, a low rosette of basal leaves is formed, but later there develops an erect central stem that is unbranched below and dichotomously branched above. The central and upper stems are light green, terete or angular, and either glabrous or lined with short fine hairs. The basal leaves are up to 2½" long and ¾" across; they are medium green, glabrous, oblanceolate, and smooth along their margins. The cauline leaves (up to 3" long & 1" across) occur in opposite pairs along the central and upper stems, where they are either sessile or clasp the stems slightly. The lower cauline leaves are oblong and smooth along the margins (see Lower Leaves), while the upper cauline leaves are lanceolate with lower teeth that are dentate. Like the basal leaves, the cauline leaves are medium green and glabrous; sometimes they are slightly ciliate along their margins. The upper stems terminate in flat-headed clusters (or dense cymes) of white flowers; each cluster spans about ½–1½" across. There is a pair of small leafy bracts where the stalks of the inflorescence dichotomously branch; these bracts are lanceolate in shape. Each flower has a small funnelform corolla with 5 spreading lobes; this corolla is white and spans about 1/6" (4 mm.) across. At the base of the flower, there is a small green calyx with 5 teeth; this calyx is much shorter than the corolla. Exerted from the corolla, there are 3 stamens and a single style. The blooming period occurs during late spring to early summer and lasts about 3 weeks. The flowers are very fragrant. Each flower is replaced by a 3-celled fruit spanning about 3 mm. long and 2 mm. across (size is variable); one cell contains a single seed, while the remaining cells are empty. An empty cell is about the same size as the fertile cell; the shape of a 3-celled fruit is globoid-angular, rather than sharply triangular. This wildflower occasionally forms loose colonies of plants.
Cultivation: The preference is partial sun or dappled sunlight, consistently moist conditions, and soil containing organic matter along with some sand or rocky material. Most growth and development occurs during the spring. The seed can remain viable in the ground for about 5 years.
Range & Habitat: Northern Corn Salad is rare in Illinois, occurring in three NE counties and two counties in the southern half of the state (see Distribution Map). It is native and state-listed as 'endangered.' This species is slightly more common in Indiana. Habitats include bottomland meadows in sandstone canyons, springs at the base of cliffs, rocky banks along woodland streams, and sandy slopes in wooded areas. In Illinois, this species is found in high quality natural areas, although it has been found in fields, roadsides, and other disturbed habitats in other states.
Faunal Associations: Little is known about floral-faunal relationships for this species. The nectar of the flowers probably attracts bees and occasional butterflies. The foliage of Valerianella spp. is readily eaten by cattle and probably other mammalian herbivores. The European species, Valerianella locusta (Māche, Lamb's Lettuce), is cultivated as a source of salad greens for humans; it has blue flowers.
Photographic Location: A bottomland meadow in a sandstone canyon at the Portland Arch in west-central Indiana.
Comments: This is one of the more attractive Valerianella spp. because its flowers are larger than average in size and they are very fragrant. This is also one of the taller species in this genus. Another species with similar-sized flowers, Valerianella chenopodifolia (Great Lakes Corn Salad), differs by having fruits that are sharply triangular in cross-section; like Northern Corn Salad, it is quite rare in Illinois. Authorities differ on how the variations of Northern Corn Salad should be classified. Mohlenbrock (2002) divides Northern Corn Salad into three different species: Valerianella intermedia, Valerianella patellaria, and Valerianella umbilicata. This tripartite division is based on minute variations in the size and shape of the fruits. Other authors (Yatskievych, 2000; Kartez, 1994) consider such variations insignificant and recognize only Valerianella umbilicata as a valid species. Another common name of Valerianella umbilicata is Navel-Fruited Corn Salad.