Vascular Plants of North Carolina
Account for Slender Rockcress - Arabis adpressipilis   (M. Hopkins) Al-Shehbaz
Members of Brassicaceae:
Members of Arabis with account distribution info or public map:
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Section 6 » Family Brassicaceae
Author(M. Hopkins) Al-Shehbaz
DistributionKnown from just a few sites in the Mountains (Buncombe and Rutherford counties) and Piedmont foothills (Alexander County). The first discoveries in the state came several decades after RAB (1968) was published.

This is a species of middle regions, mainly west of the Appalachians. It ranges from OH to IL and south to TN and AR, with disjunctions to western NC and VA.
AbundanceVery rare and local, with most records from the Brushy Mountains in Alexander County. This is a State Endangered species.
HabitatThis species grows in thin soil around mafic rock outcrops. Though the domes in the Brushy Mountains are granitic (felsic), there are some minerals embedded in the rock that weather to give a high pH soil to some of these domes.
See also Habitat Account for Basic Barrens and Glades
PhenologyBlooms in April and May, and fruits in May and June.
IdentificationThis is a slender and somewhat wand-like species with a stem, occasionally branched at the base, that grows to about 1.5 feet tall. The lower part of the stem is usually quite hairy. There is a small basal rosette, of short elliptical leaves. The stem leaves are alternate, mostly pubescent (especially the lower ones), strongly ascending, and linear to lanceolate and about 1-1.5 inches long, more thinly scattered on the upper part of the stem. The raceme at the end of the stem has scattered fairly small flowers, each with 4 white petals and about 2/5-inch across. The fruit, siliques, are quite long and tubular, about 2-3 inches long, and strongly ascending to almost erect. The numerous nearly erect capsules are quite striking, if you are able to find the species in fruit. The other species in the genus, in Weakley's classification, is A. patens, but it has larger petals and the leaves are wider and more clasping the stem.
Taxonomic CommentsPlants in NC were first placed in Arabis hirsuta, which is a Western species; it was since moved into A. adpressipilis. Most references name the taxon as A. pycnocarpa var. adpressipilis, but Weakley (2018) uses the full species for this taxon.

Other Common Name(s)Creamflower Rockcress, Hairy Rockcress
State RankS1
Global RankG5T4Q [G4Q]
State StatusE
US Status
USACE-agcp
USACE-emp
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