Manual de Plantas de Costa Rica 119 
Gentry’s (1995) data, from the same geographic area, between 1900 and 2775 m ele- 
vation, with 0.1 ha plots. 
The Cordillera Central is separated from the Cordillera de Talamanca on the 
Caribbean slope by the valley of the Rio Reventaz6n, where one finds a unique mixture 
of species not found anywhere else on that slope. Various species are known in Costa 
Rica only from this valley, e.g., Aechmea aquilega, Licaria multinervis, and Psychotria 
viridis, while others are typical of moist, seasonal climates along the Pacific coast; 
some species in this latter category are Adelia triloba, Amyris pinnata, Anacardium ex- 
celsum, Arrabidaea patellifera, A. verrucosa, Brosimum alicastrum, Cheiloclinium 
cognatum, Clarisia racemosa, Coutarea hexandra, Croton skutchii, Eugenia acapul- 
censis, E. siggersii, Guettarda turrialbana, Hasseltia floribunda, Ipomoea dumosa, 
Kohleria spicata, Lafoensia punicifolia, Lonchocarpus guatemalensis, Mansoa parvi- 
folia, Nectandra hihua, Odontocarya truncata, Olmedia aspera, Pogonopus exsertus, 
Poulsenia armata, Pseudobombax septenatum, Pseudolmedia spuria, Saurauia yasi- 
cae, Sideroxylon contrerasii, Smilax domingensis, Spondias radlkoferi, Stemmadenia 
donnell-smithii, Tapirira mexicana, Trichilia martiana, Vernonia triflosculosa, Zapo- 
teca costaricensis, and Zuelania guidonia. As indicated by Herrera (1985), the basin of 
the Rio Reventaz6n encompasses a broad range of climates, including rather dry con- 
ditions in the central and lower part of the valley, where a Pacific-type precipitation 
regime reigns. 
Cordillera de Talamanca 
This mountain range, the most massive and extensive in Costa Rica, comprises a broad 
chain of peaks trending in a northwest-to-southeast direction for 320 km, from near San 
José and Cartago to beyond the Panamanian border. The major peaks lie along the Con- 
tinental Divide and include the highest points in the country, ranging in elevation from 
ca. 1756 m (Cerro Turrubares) to 3819 m (Cerro Chirripd). For more details, see the 
section on Physical geography in the chapter on The physical environment. 
The Cordillera de Talamanca exhibits a great variety of topographic features over 
a vast area, consisting chiefly of Tertiary marine sediments mixed with plutonic and 
volcanic rocks of the Upper Miocene (Gémez P., 1986). Reflecting its great age as well 
as its wide range of altitude and climate and vegetation types, this cordillera has a com- 
plex and diverse flora, for which we can here give only a rough picture of the most 
salient features. The most intensively studied part of this range, floristically and eco- 
logically, has been the Pacific slope, particularly in the area above 2000 m near Cerro 
de La Muerte and Cerro Chirripé6 (see, e.g., Kappelle, 1996, 2001). 
On the Pacific side of the Cordillera de Talamanca, as in the other cordilleras, a cer- 
tain number of primarily lowland elements occur up to 1000-1200 m, e.g., Annona 
amazonica, Anthodiscus chocoensis, Brosimum guianense, B. lactescens, Calophyllum 
brasiliense, Casearia arborea, Dussia macroprophyllata, Guapira costaricana, Guat- 
