Vascular Plants of North Carolina
Account for Azure Bluet - Houstonia caerulea   L.
Members of Rubiaceae:
Members of Houstonia with account distribution info or public map:
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Section 6 » Order Rubiales » Family Rubiaceae
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DistributionNearly throughout the state, but absent along the immediate coast.

This is a widespread Eastern species, found from eastern Canada south to northern FL and LA.
AbundanceCommon to very common across the state; perhaps only frequent to common in the Mountains; scarce near the coast.
HabitatThis is a very familiar species of dry to mesic clay soil, typically where there is little competition -- stream banks, wooded borders, fields, openings in upland woods, powerline clearings, and many other places, including lawns.
PhenologyBlooms from March to May, and fruits from May to June.
IdentificationThis is a tiny and very slender species, a welcome harbinger of spring, despite its very small size. It grows only to about 4 inches tall, with a cluster of small, rounded basal leaves. There are only one to several tiny pairs of opposite stem leaves, each oblanceolate but barely 1/5-inch long. The top of the stem, or any of the few branches, contains the familiar bluet flower -- 4 spreading light blue petals with a yellow eye. The spread of the flower is about 2/5-inch across. Usually, many will be found blooming in a small area. H. pusilla is somewhat similar, but even smaller, and it has a dark red eye and a more medium blue to lavender blue flower. H. serpyllifolia, a mountain plant, can grow near this species, but it has a creeping stem that sends up flowering stalks, and it has a richer blue flower.
Taxonomic CommentsA few references have this and other Houstonia species in the genus Hedyotis; most do not.

Other Common Name(s)Quaker Ladies, Innocence, Common Bluet, Little Bluet, Bluets. The first two are quirky and idiosyncratic.
State RankS5
Global RankG5
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B.A. SorrieSlope at margin of Rocky River, April 2010. UnionPhoto_natural
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