unicate

noun

1. A biological specimen that has no duplicates.

   “Dead inflorescences and infructescences are well worth collecting if no fresh material is available or if fresh material is only sufficient for a unicate or one duplicate.”

   “Each collection, which may be a unicate or several specimens as duplicates in several herbaria, constitutes a record in the Conifer Database.”

2. A species that occurs at only a single geographical site.

   “Our data perhaps are more robust for analyzing patterns of endemism because some nuclei for which we have few inventories show high numbers of unicates (e.g., Caribbean, Mexico), and others for which we have sampled far more thoroughly show low numbers (e.g., Brejo and Peri-Caatinga). Though the percentage of unicate species varies widely from 1.9 to 77.5 percent, in general it is high, with 12 of 23 nuclei showing greater than 20 percent unicates, suggesting high endemism.”