Vascular Plants of North Carolina
Account for Thymeleaf Bluet - Houstonia serpyllifolia   Michaux
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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DistributionThroughout the Mountains. A record for Rowan County, in the central Piedmont, is shown in RAB (1968), but SERNEC has no voucher specimen for that county. As this is well east of the expected range, the website editors have removed it from the map.

This is a Central and Southern Appalachian endemic species, ranging from southwestern PA to northern GA.
AbundanceFrequent to common across the Mountains, probably more numerous and widespread in NC than in any other state in its range.
HabitatThis species prefers somewhat damp ground, but in mostly shaded and often rocky places. It grows along forest stream margins, seepages, spray cliffs, rich cove forests, and even into grassy balds (at least where damp or with seepage).
PhenologyBlooms in May and June, and fruits shortly after flowering.
IdentificationThis is a familiar montane spring wildflower of moist forests, but it is quite tiny in size. It has a prostrate stem, creeping for a few inches along the ground, but sending up several flowering stalks to about 4 inches tall. The opposite leaves along the horizontal and vertical stems are tiny, ovate, and barely 1/10-inch long. The flowers, one per stalk, are like those of H. caerulea but are richer, more medium blue in color, with 4 spreading petals and a spread flower about 3/5-inch across; the eye is yellow or white. As this species is creeping, it typically grows in tight and dense masses.
Taxonomic CommentsNone

Other Common Name(s)Appalachian Bluet
State RankS3 [S4]
Global RankG4?
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US Status
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B.A. SorrieMount Mitchell near summit, late 1960s. YanceyPhoto_natural
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