Growing in the understory of montane pine forest at 1700 m. Identified using the key in Caluff 2006 (https://www.jstor.org/stable/pdf/3997723.pdf): pinnae and pinnules deltoid to deltoid-ovate, rigid, patent; stipe with numerous needle-shaped thorns, 2-4 mm long. In the only other Hispaniolan congener, O. scandens (syn. uncinella), the thorns are much shorter and conical, or entirely lacking (op. cit.).