KEY TO IDENTIFICATION OF ISOPTERYGIOPSIS SPECIES

1. Leaves ovate, strongly concave to keeled at base, cucullate, abruptly acuminate; stem central strand absent ....................................... 2. I. catagonioides

— Leaves ovate-lanceolate, moderately concave, not keeled at base, not cucullate, gradually acuminate; stem central strand usually present ......................... .................................................... 1. I. muelleriana