Manual de Plantas de Costa Rica 199 
pare these regions with regard to the taxonomic and habital composition of their floras, 
through a relatively impersonal analysis of the data. 
A discussion of the floristic differences among these four regions can best 
be viewed in reference to the summary of the entire flora. Our present calculations 
of species totals (which, taken at the time of writing of this introduction, may vary 
slightly from the actual numbers), based on Manual treatments and the specimen 
database, show a considerable increase compared to those published by Standley 
(1938b: 1569) for the same groups, excluding ferns, which he did not treat or tabulate 
(see Table 3). 
It should be noted that of the phenomenal 537 species of Piperaceae reported by 
Standley (more accurately, by Trelease in Standley), today only about 200 are recog- 
nized. Trelease was a prodigious “splitter” (as Standley himself was well aware; see 
Morton, 1963: 18), and most of his names are accordingly now considered synonyms. 
But for that anomaly, Standley’s data would show the same five families as most di- 
verse, albeit in a slightly different order, with Rubiaceae (251 spp.) just below Poaceae 
(see Table 4). 
Ignoring the large number of once or rarely collected, weedy, exotic grasses that 
have accumulated over the years (often without really becoming established), the 
Poaceae, Asteraceae, and Rubiaceae that form part of the actual floristic landscape are 
nearly equal in number of species. The most diverse genera of vascular plants in Costa 
Rica are Epidendrum (158 spp.), Pleurothallis (152 spp.), Elaphoglossum (140 spp.), 
and Maxillaria and Miconia (both with 107 spp.), followed by Peperomia, Piper, and 
Psychotria, each with about 100 species. The ferns and fern allies, taken together, are 
approximately on par with the orchids in terms of diversity; their ca. 1100 species are 
divided nearly equally between epiphytes and terrestrial herbs, except for about 40 spe- 
cies of arborescent ferns and a few viny species. 
Our task of discussing the complex flora of Costa Rica is made somewhat easier 
(or at least more accountable) than it was for earlier botanists by virtue of databases. 
With the computerized label data of approximately 120,000 specimens in the INBio 
herbarium (accounting for at least 93% of the known vascular flora), we have at our dis- 
Table 3. Total species in major groups now vs. Standley. 
Manual Standley 
Ferns and fern allies 1B n.a. 
Gymnosperms 13 9 
Monocots 2986 1946 
Dicots 5250 4130 
Total seed plants 8249 6085 
Total vascular plants 9361 
