Gratiola quartermaniae (Quarterman’s Hedge Hyssop):
Gratiola quartermaniae was first described from Eastern North America by Estes and Small in 2007. The species typically grows in thin, seasonally saturated soil over exposed limestone or dolomite bedrock. This habitat is typically found associated with limestone glades, barrens, prairies, and alvars. A limestone glade is an area of exposed limestone bedrock with little to no soil overtop. The species is most common in the limestone cedar glades of central Tennessee and northern Alabama, though it also occurs in primarily limestone habitats in northeastern Illinois, central Texas, and southeastern Ontario. Similar distribution patterns are seen in several other species which grow with G. quartermaniae including Clinopodium arkansanum (Nutt.) House, Grindelia lanceolata Nutt, Heliotropium tenellum (Nutt.) Torr., Isoetes butleri Engelm., Juncus filipendulus Buckl., and Minuartia patula (Michx.) Mattf.
During a 2012 search for the species, 49 new locations were identified for G. quartermaniae. These collections represent 7 new county records, including Bosque, Denton, Hood, Johnson, Parker, Tarrant, and Wise counties. At least one voucher specimen from each county was collected and deposited in the BRIT herbarium. All populations were found on seasonally wet Walnut Limestone glades and are the first to be found in the Texas Fort Worth Prairie and Limestone Cut Plain. These collections indicate that the species and its calcareous glade habitat are much more abundant in Texas than previously thought.
CITATION: Taylor, K.N. & R.J. O’Kennon. 2014. Expanded distribution of Gratiola quartermaniae (Plantaginaceae) in Texas, U.S.A. J. Bot. Res. Inst. Texas 8(1):333–337.