Language: English with bilingual summaries in English and Spanish
Volume 73 covers six families.
Part 73: Crassulaceae
The Crassulaceae of Ecuador are revised. Two genera are native in Ecuador: Crassula (2 spp.) and Echeveria (1 sp.). The genus Kalanchoe has 3 naturalized species.
Part 74: Saxifragaceae
The Saxifragaceae of Ecuador are revised. Only one genus, Saxifraga with two species, is native in Ecuador.
Part 75A: Hydrangeaceae
The Hydrangeaceae of Ecuador are revised. Five species of Hydrangea are native in Ecuador, all belonging to the section Cornidia. One new combination is made, Hydrangea peruviana var. Oerstedii (Briq.) Freire Fierro.
Part 75B: Grossulariaceae
The Grossulariaceae of Ecuador are revised. Nine species of Ribes are native in Ecuador, all belonging to the subgenus Parilla.
Part 76A: Escalloniaceae
The Escalloniaceae of Ecuador are revised. One genus, Escallonia, is native in, Ecuador, where it has five native species.
Part 76B: Phyllonomaceae
No species of Phyllonoma has been documented from Ecuador, but Ph. ruscifolia is considered likely to occur, based on its general distribution range.