Manual de Plantas de Costa Rica |Plan of the Manual] 243 
ith this in mind, species have not been included, as a general rule, on a hy- 
pothetical basis, e.g., because they have been collected near the border, or 
in countries both to the north and south. Exceptions have been made only 
rarely, for species collected on or extremely near the border (within ca. 5 km) in habi- 
tats extending into Costa Rica (e.g., on the Nicaraguan shore of the Rio San Juan, or 
the Panamanian slopes of Cerro Pando). The reader should be aware that the mountains 
of western Panama (especially from the vicinity of Cerro Punta east to the La Fortuna 
region and Cerro Colorado) harbor many hundreds of plant species that are not treated 
in this Manual, but which could eventually be found in remote corners of eastern Costa 
Rica. Nonetheless, it is expected that omissions from the Manual, inevitable under any 
circumstances, will not seriously compromise the practical utility of this work (and will 
be the delight of future botanists). 
Taxonomic coverage 
The Manual intends to treat all species of seed plants vouchered from Costa Rica by 
authoritatively identified herbarium specimens. Both indigenous species and natural- 
ized exotics are accounted for, as well as commercial exotic species grown on a large 
scale (whether for local consumption or export). Non-native pot plants and patio orna- 
mentals have, in general, not been treated formally (though they may be mentioned); 
but many gray areas exist, and decisions were made on a case-by-case basis. See Ham- 
mel (2001) for an account of native species grown for ornament in Costa Rica. 
Infraspecific taxa (subspecies, varieties, and forms) are not keyed or formally de- 
scribed in the present work, but are enumerated and briefly characterized in the species 
discussions. Hybrids may or may not be mentioned, depending on their distinctiveness 
and abundance. Generally, hybrids are not treated in full, with the exception of some 
well-known crops, e.g., Musa Xparadisiaca (plantain), and a few other entities that 
behave as species and are established as populations (not just isolated individuals) in 
the wild, e.g., Crocosmia Xcrocosmiiflora (Iridaceae) and Ipomoea Xleucantha (Con- 
volvulaceae). 
The existence of at least one herbarium specimen from Costa Rica (or extremely 
nearby; see above) was made a nearly inflexible (see section on Voucher citation, 
below) prerequisite for full treatment of taxa in the Manual. Sight records and un- 
vouchered literature reports have been disregarded in this context. 
Names 
Within the three major groups treated in the Manual (gymnosperms, monocotyledons, 
and dicotyledons, presented in that order), family, genera, and species treatments are 
