Complex sentence: When dry, the leaves of "Psychotria viridis" usually are gray or reddish brown and are similar to those of a few other New World species of "Psychotria".
Split into simpler sentences: When dry, the leaves of Psychotria viridis usually are gray or reddish brown. The leaves of Psychotria viridis are similar to a few other New World species of "Psychotria".