Vascular Plants of North Carolina
Account for Tiny Bluet - Houstonia pusilla   Schoepf
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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AuthorSchoepf
DistributionEssentially throughout the Piedmont and the Coastal Plain, except for the far eastern areas; no records yet east of Hertford, Bertie, Pitt, and Duplin counties. Scattered in the mountains.

This is a Southern species, ranging from MD and KS, south to western FL and central TX.
AbundanceCommon in the central and eastern Piedmont and western Coastal Plain. Fairly common in the central Coastal Plain, but absent in the far eastern counties. Uncommon in the mountains and western Piedmont. The NCNHP's State Rank of S4 is clearly incorrect, as it is certainly an S5 species in the state.
HabitatThis species, as with H. caerulea, but even more so, grows in dry clay soil without much competition. It is found in fields, lawns, margins of trails, edges of woods, and other places with low vegetation.
PhenologyBlooms in March and April, and fruits soon after flowering.
IdentificationThis is a familiar species except for people in the eastern and mountain parts of the state, quite easily found in spring in compacted, dry soil. It is extremely slender, reaching only about 3" tall on average, with some spatulate basal leaves only about 1/2" long. There are only one or two pairs of tiny, opposite stem leaves. The single flower atop the stem or any branches has 4 spreading petals, but the flower is only about 1/4" across, being darker lavender blue, with a dark red eye. H. caerulea is similar but slightly taller and has a slightly larger flower that is light blue with a yellow eye. As with that species, normally a few dozen plants can grow in a small patch of ground.
Taxonomic CommentsSome references use the genus name of Hedyotis, but most use Houstonia.

Other Common Name(s)Small Bluet(s)
State RankS4 [S5]
Global RankG5
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