Rhynchospora stiletto Naczi & Ciafré. Phen: Jul-Aug. Hab: Fens, calcareous wet prairies, limestone river scour outcrops. Dist: Sc. TN to ne. AL; se. MO and adjacent ne. AR.
ID notes:Rhynchospora stiletto appears to be closely allied to R. chalarocephala, and is distinguished primarily by its longer tubercle 2.3-2.7 mm long or 0.53-0.58x as long as achene body (vs. 1.2-1.5 mm long or 0.39-0.48x as long as achene body in R. chalarocephala). It is only known from a small number of rare limestone-laden sites in central TN, ne. AL, se. MO, and ne. AR; further surveys are needed within its range.
Origin/Endemic status: Endemic
Taxonomy Comments: See Ciafré & Naczi (2022) for detailed discussion.
Synonymy: = Ciafré & Naczi (2022); < Rhynchospora chalarocephala Fernald & Gale – C, FNA23