Jepson Manual Vascular Plants of California - single most comprehensive resource on California's diverse flora; integrates the latest science with the results of intensive fieldwork, institutional collaboration, and efforts of hundreds of contributing authors into an essential reference on California's native and naturalized vascular plants. Includes treatments of many newly described or discovered taxa and recently introduced plants.
Flora of North America - FNA presents for the first time, in one published reference source, information on the names, taxonomic relationships, continent-wide distributions, and morphological characteristics of all plants native and naturalized found in North America north of Mexico.
E-Flora BC - Electronic atlas of the flora of British Columbia; a biogeographic atlas of the vascular plants, bryophytes, lichens, algae, fungi and slime molds of British Columbia.
Manual de plantas de Costa Rica - v. 1 (Introduction & History); v.2-3 (Gymnosperms & Monocots); in Spanish and English
Ecological Flora of the British Isles - data on 3842 species of higher plants that occur in the British Isles, information on taxonomy (family, genus, specific name, authority, and vernacular name, together with a synonomy), a suite of over 130 ecological and morphological characteristics, vice-county distribution in Britain, European distribution by country, mycorrhizal associations, associated phytophagous insects and fungi. links to distribution maps, accounts from the Ecological Flora series in the Journal of Ecology, FAO and CABI fact sheets, the Database of Insect Food Plants, and UK Herbarium sheets.
Flora Iberica - flora of the Iberian Peninsula and Balearic Islands.
Flora of France - nomenclature and synonymy of the French flora
Flora of New Zealand - includes flowering plants, gymnosperms, ferns, and bryophytes; naturalised as well as indigenous plants.
Flora Zambesiaca - taxonomic study of native and naturalised plants of the Zambezi River basin, covering the territories of Botswana, Malawi, Mozambique, Zambia, Zimbabwe and the Caprivi Strip.
NT Flora - Northern Territory (Australia) Flora online
New South Wales Flora Online - a prototype presented as a demonstration, and not necessarily as an authoritative resource.