| Revision of Pearcea (Gesneriaceae) | 1996/01/01 | English | |
| Studies in the genus Boerhavia L. (Nyctaginaceae) | 1978/01/01 | English | |
| A Revision of the Lichen Family Thelotremataceae in Panama | 1978/01/01 | English | |
| A Revision of the Genus Polylepis (Rosaceae: Sanguisorbeae) | 1979/01/01 | English | |
| Atlas of Hairs for Neotropical Melastomataceae | 1986/01/01 | English | |
| Seed Micromorphology of Neotropical Begonias | 1999/01/01 | English | |
| The morphology and taxonomy of Aneilema R. Brown (Commelinaceae) | 1991/01/01 | English | |
| Vascular Flora of the Northern Marianas Islands | 1975/01/01 | English | |
| Flora of Micronesia, 1: Gymnospermae | 1975/01/01 | English | |
| A generic review of the tribe Liabeae (Asteraceae) | 1983/01/01 | English | |
| History of Botanical Exploration in Territorio Federal Amazonas, Venezuela | 1984/01/01 | English | |
| Classification, Evolution, and Phylogeny of the Families of Dicotyledons | 1986/01/01 | English | |
| A revision of the Genus Aglaonema (Araceae) | 1969/01/01 | English | |
| Revision of the South American Genus Otachyrium (Poaceae: Panicoideae) | 1984/01/01 | English | |
| New Records of Marine Algae from the 1974 R/V Dolphin Cruise to the Gulf of California | 1976/01/01 | English | |
| Polynesian Plant Studies 1-5 | 1975/01/01 | English | |
| Palynological study of the Liabeae (Asteraceae) | 1986/01/01 | English | |
| Leaf Anatomy and Systematics of New World Velloziaceae | 1974/01/01 | English | |
| A study of the tribe Gesneriaceae, with a revision of Gesneria (Gesneriaceae-Gesnerioideae) | 1976/01/01 | English | |
| An introduction to the Botanical Type Specimen Register | 1973/01/01 | English | |
| Growth and Population Dynamics of Espeletia (Compositae) in the Venezuelan Andes | 1981/01/01 | English | |
| Morden-Smithsonian Expedition to Dominica: The Lichens (Graphidaceae) | 1978/01/01 | English | |
| Some Latin American Genera of Hypnaceae (Musci) | 2009/01/01 | English | |
| A monograph on the foliar anatomy of the genera Connellia, Cottendorfia and Navia (Bromeliaceae) | 1969/01/01 | English | |
| Revision of Kohleria (Gesneriaceae) | 1992/01/01 | English | |
| The Genus Thrinax (Palmae: Coryphoideae) | 1975/01/01 | English | |
| A review of Philippine Hookeriaceous taxa (Musci) | 1990/01/01 | English | |
| Marine Algae of Dominica | 1970/01/01 | English | |
| Marine algae of the northern Gulf of California : Chlorophyta and Phaeophyceae | 2010/01/01 | English | |
| A Revision of the Genus Polylepis (Rosaceae: Sanguisorbeae) | 1979/01/01 | English | |