Vascular Plants of North Carolina
Account for Harperella - Harperella nodosa   RoseOnly member of Harperella in NC.
Google Images
Section 6 » Family Apiaceae
Show/Hide Synonym
AuthorRose
DistributionLimited to only two known sites along rivers in the lower Piedmont -- the Tar (Granville County) and the Deep (Chatham and Lee counties).

This species has a very disjunct range, from MD and WV south to GA and AL, and also in AR and OK. Note that Weakley (2018) considers now one species (H. nodosa) that many other references have split into two or three species. See Taxonomic Comments.
AbundanceExtremely rare in NC, with the Tar River site(s) still in somewhat fair condition, but the Deep River population is in very poor condition. However, these populations wax and wane yearly, owing mainly to water levels and amount of scouring. This is a Federal and State Endangered species -- no matter what name it goes by!
HabitatIn NC, it is found only on gravel bars and margins of tiny "islands" within somewhat swiftly moving rivers, where some amount of scour is necessary to knock back some competing species at the expense of this one.
See also Habitat Account for Piedmont and General Rocky Rivers
PhenologyBlooms from July to August, and fruits soon after flowering.
IdentificationThis is a very slender and somewhat small species (for an umbel), with an erect to leaning stem about 1' tall on average and few branches. The leaves are essentially filiform "tubes", about 1-2" long, and only a few of them are present, such that the stem appears almost free of leaves. At the stem top and ends of the few branches grow the small umbels of white flowers, usually consisting of 15-20 or more umbellets loosely in a flat-topped arrangement. Without the flowers, however, spotting this plant on the gravel bars where it occurs can be very difficult, especially if other plants are growing in the same area. At least, a number of Harperella plants can and do occur in close proximity. But, it can be an exasperating species for people monitoring the populations, as the plants can "fail to appear" at the right time of year, owing to the wrong water levels and other factors.
Taxonomic CommentsProbably more than any single species on the NC state list, this one has been shifted around from genus to genus and species to species as any! RAB (1968) listed it as Ptilimnium fluviatile. NatureServe and many other more recent references have moved it to P. nodosum. It has also been moved to Harperella nodosa, and to H. vivipara. Weakley (2018) has settled, at least for now, on H. nodosa.

Other Common Name(s)Piedmont Mock-Bishopweed -- the proper or best name if the species were still in the genus Ptilimnium, commonly known as the Mock-Bishopweeds.
State RankS1
Global RankG2
State StatusE
US StatusLE
County Map - click on a county to view source of record.
Select a source
AllHerbaria
Literature
Select an occurrence type
AllCollection_naturalLiterature_natural