The following websites may be useful when looking up scientific plant names:
GRIN taxonomic data provide the structure and nomenclature for accessions of the National Plant Germplasm System, part of the U.S. Department of Agriculture’s National Genetic Resources Program. GRIN Taxonomy for Plants represents all families and genera of vascular plants and 51,691 species from throughout the world, especially economic plants and their relatives. It also provides information on scientific and common names, classification, distribution, references, and economic impacts.
USDA’s PLANTS Database provides standardized information about vascular plants, mosses, liverworts, hornworts, and lichens of the United States and its territories.
ITIS provides authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world. ITIS is a partnership of U.S., Canadian, and Mexican agencies (ITIS- North America); other organizations; and taxonomic specialists.
IPNI is the product of a collaboration between The Royal Botanic Gardens, Kew, The Harvard University Herbaria, and the Australian National Herbarium. It is a database of names and associated basic bibliographical details of seed plants, ferns and lycophytes.