Vascular Plants of North Carolina
Account for Large Thymeleaf Sandwort - Arenaria serpyllifolia   L.
Members of Arenaria with account distribution info or public map:
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Section 6 » Order Caryophyllales » Family Caryophyllaceae
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AuthorL.
DistributionThe distribution in NC is not known with any certainty, but seems to occur across the mountains and Piedmont, and into the Coastal Plain to an undetermined extent. Many specimens labeled A. serpyllifolia may have used "lumpy" taxonomy. All specimens labeled A. serpyllifolia need to be keyed to that species or to A. leptoclados. Some of the 46 county records mapped by USDA may prove to be A. leptoclados. The website editors have chosen only to map specimens at NCU and DUKE on the map below (as these are the only two herbaria listed for the very similar A. leptoclados); this suggests that all other herbaria have not yet separated out their "A. serpyllifolia" records into these two species..

Native of Eurasia and northern Africa; in N.A. throughout the US and southern Canada.
AbundanceBased on the distribution of specimens at NCU and DUKE, it seems to be fairly common in the mountains, infrequent in the Piedmont, but scarce to absent eastward. This is at odds with Weakley's (2018) range map, which indicates this species is common throughout but the extremely similar A. leptoclados is rare and only in the Coastal Plain.
HabitatDry sandy roadsides, disturbed ground, sidewalk cracks, driveways, campus weed.
PhenologyFlowering and fruiting March-June.
IdentificationThis sprawling to erect plant often grows less than 6 inches tall, but may reach a foot. The stems are slender and pubescent, with pairs of tiny, ovate leaves. The flowers occur in terminal cymes, the sepals are green, the petals are white and shorter than the sepals. The leaves of the native A. lanuginosa are much longer and relatively narrower. The seeds of A. serpyllifolia are 0.5-0.6 mm long, versus less than 0.4 mm long for A. leptoclados. Also, that species has the capsule nearly straight-sided, as opposed to an ovoid capsule on A. serpyllifolia.
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Global RankGNR
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