Vascular Plants of North Carolina
Account for Pineland Squarehead - Tetragonotheca helianthoides   L.
Members of Asteraceae:
Only member of Tetragonotheca in NC.
Google Images
Section 6 » Order Asterales » Family Asteraceae
Show/Hide Synonym
DistributionSouthern and far eastern Piedmont, Sandhills, and southern low Mountains. This species occurs sporadically on the landscape, with much apparently suitable habitat between populations.

Southeastern VA and TN, south to central FL and MS.
AbundanceSeemingly declining, and now mostly rare everywhere, but very locally uncommon in the Sandhills; very rare in the eastern Piedmont. Clearly is now strongly declining in the Piedmont and Mountains. Can be quite numerous at a few Sandhills sites, but most populations are very small. Likely has disappeared from many or most Piedmont/Mountain counties. This is a Watch List species, with a State Rank of S2S3.
HabitatMesic to dry deciduous (oak-hickory) and pine-deciduous woodlands, mainly along the borders and in openings; Longleaf Pine-Wiregrass uplands (in loamy sands). Responds rather well to fire. Reasons for its extreme local populations are not clear, but declines outside the Sandhills probably relate to fire suppression in these areas, as few if any such sites are on managed/protected lands.
PhenologyFlowering and fruiting April - early July.
IdentificationPineland Squarehead is unlike any other member of the aster family. The plant is low-growing (1-2 feet), has a few to several pairs of broadly elliptical, mostly sessile, toothed leaves, and topped by a single head on a branch (there may be two or three such branches on a plant). The head has four broadly ovate green bracts ("tetragonotheca", or 4-angled container) supporting a large, greenish brown disk and about 10 broad yellow rays. Such a flower has a spread of often 3-4 inches, huge for a composite species. Sadly, this wonderful and unique species is hard to find in NC, even in the Sandhills, but once seen it is never forgotten, especially in bloom.
Taxonomic CommentsNone

Other Common Name(s)Pineland Nerveray, Squarehead, Pineland-ginseng
State RankS2S3
Global RankG5
State StatusW1
US Status
County Map - click on a county to view source of record.
Photo Gallery
B.A. SorrieRichmond County, 2010, Sandhills Game Land, loamy sand slope by Nursery Lane. RichmondPhoto_natural

View Mapping Selection Options
Select a source
Select an occurrence type