Manual de Plantas de Costa Rica 129 
Festuca herrerae, Halenia aquilegiella, Hesperomeles heterophylla, Hieracium sphag- 
nicola, Hypericum costaricense, H. irazuense, Myrrhidendron donnellsmithii, Nipho- 
geton chirripoi, and Pernettya prostrata. 
The Caribbean slope of the Cordillera de Talamanca has been poorly explored 
floristically, in part for its isolation but also due to legal considerations, because a large 
portion of its territory lies within Amerindian reservations. In the highest parts (2000— 
3300 m), in the vicinity of Chirrip6 National Park, two floristic studies concluded that 
some species are restricted to one or the other of the two slopes, although the majority 
are shared (see Kappelle, 1992; Kappelle & Gomez P., 1992). Various important mon- 
tane elements were also documented in the 1000—2000 m range on the Caribbean 
slope, including Alfaroa costaricensis, Alzatea verticillata, Blechnum fragile, Celas- 
trus vulcanicola, Cybianthus costaricanus, Gonocalyx almedae, Gordonia brandegeéi, 
Greigia sylvicola, Ilex chiriquensis, Licania jefensis, Magnolia poasana, M. sororum, 
Microtropis occidentalis, Notopleura pithecobia, Ocotea austinii, Phyllonoma tenui- 
dens, Podocarpus oleifolius, Prestoea acuminata, Rondeletia buddleioides, Ruagea 
glabra, Senecio multivenius, Styrax argenteus, and Zanthoxylum melanostictum. The 
mere presence of genera such as Alfaroa, Alzatea, Gordonia, Greigia, Magnolia, Nyssa 
(Hammel & Zamora, 1990), Phyllonoma, 
Podocarpus, and Styrax reflects a mixture 
of elements from widely disparate geo- 
graphic origins. The majority of these, as 
well as a major portion of the species re- 
cently reported as new to science or new to 
the country, are found at middle elevations 
(1000-2000 m). 
In summary, the cordilleras present a 
rich and diverse flora even at their highest 
elevations (as in the paramos), and their 
middle elevations harbor much of the most 
important flora of the country, taxonomi- 
cally and phytogeographically. The sug- 
gested limits of this most diverse elevational band vary. For the Pacific slope, Fournier 
O. (1969) proposed a (700—)1000—1500 m band; later, Gomez P. (1986) suggested an 
800-1500 m band, and for the Caribbean slope, a 500— 1500 m band. Results from re- 
cent studies, using quantitative methods (plots and transects) within a single region on 
the Caribbean slope (Braulio Carrillo National Park), show that the most diverse ele- 
vational band can vary according to the sampling method used. Lieberman et al. (1996), 
using | ha plots, found the highest diversity at 300 m elevation, while Boyle (1996), 
using 0.1 ha transects, delimited the 750—1000 m band as that of peak diversity. This 
suggests that more studies are needed, using quantitative methods, in order to better de- 
limit the most diverse elevation, which must also vary according to the slope and the 
Nyssa talamancana 
