This is a dainty plant that produces abundant small flowers if it receives some sunlight. Long-Leaved Bluets is smaller in size than Houstonia purpurea (Broad-Leaved Bluets), but larger in size than several other bluets, including Houstonia caerulea (Quaker Ladies) and Houstonia pusilla (Small Bluets). Long-Leaved Bluets is very similar in appearance to Houstonia canadensis (Canada Bluets); some authorities consider the latter species to be a variety of the former, or Houstonia longifolia ciliata. Canada Bluets is supposed to have more persistent basal leaves with ciliate margins, flowering stems that are fewer in number and less branched, and slightly longer corolla lobes. Because the ranges of these two species overlap and they may intergrade, it is not always possible to reliably assign field specimens to one species or another. A scientific synonym of Long-Leaved Bluets is Hedyotis longifolia.

This native perennial wildflower is 4-10' tall and more or less erect. A small rosette of basal leaves may be produced, but it withers away before the flowers bloom. The margins of these basal leaves, when present, are hairless. Multiple flowering stems are produced that often branch. These stems are light to medium green, 4-angled, and either hairless or slightly hairy along their angled margins. Pairs of opposite leaves occur at intervals along each stem. These leaves are about ½–1' long and less than ¼' across; they are medium green, lanceolate-oblong or linear-lanceolate, smooth or ciliate along their margins, and single-veined. Secondary leafy stems often develop from the axils of the opposite leaves along the primary stem. The upper stems terminate in small flat-headed clusters of flowers. Individual flowers are about ¼' across, consisting of a tubular corolla with 4 spreading lobes and a green calyx with 4 linear-lanceolate teeth. The color of the corolla can vary from pale purplish pink to white; there are conspicuous hairs along its throat. The flowers of Long-Leaved Bluets are dimorphic

Long-Leaved Bluets occurs occasionally in northern and southern Illinois, while in the central section of the state it is largely absent (see Distribution Map). Habitats include dry gravel prairies, hill prairies, rocky glades, and rocky upland woodlands. This wildflower is normally found in high quality natural areas.

Houstonia longifolia var. glabra Terrell:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Houstonia longifolia var. compacta Terrell:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Houstonia longifolia Gaertn.:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Canada

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Isotype for Houstonia longifolia var. glabra Terrell
Catalog Number: US 3585483
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): E. E. Terrell
Year Collected: 1956
Locality: Summit of Whitesides Mtn., about 5 mi. NE of Highlands, Jackson County., Jackson, North Carolina, United States, North America
Elevation (m): 1494

Long-Leaved Bluets occurs occasionally in northern and southern Illinois, while in the central section of the state it is largely absent (see Distribution Map). Habitats include dry gravel prairies, hill prairies, rocky glades, and rocky upland woodlands. This wildflower is normally found in high quality natural areas.

The flowers are pollinated primarily by small bees, including Halictid bees (Lasioglossum spp., Halictus spp., etc.), Masked bees (Hylaeus spp.), Little Carpenter bees (Ceratina spp.), and Mason bees (Hoplitis spp.). These insects suck nectar and collect pollen from the flowers. The caterpillars of a small moth, Thyris maculata (Spotted Thyris), feed on the leaves of Houstonia spp. (Bluets). The foliage is not known to be toxic, therefore it may be eaten occasionally by the Cottontail Rabbit.

Rounded Global Status Rank: G4 - Apparently Secure

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: NNR - Unranked

The preference is full or partial sun, mesic to dry conditions, and a rather sterile soil that is rocky or gravelly. This species will adapt to rock gardens and it is not difficult to cultivate.