Manual de Plantas de Costa Rica 117 
squamigera, Dysopsis glechomoides, Eriosorus warscewiczii, Gaultheria erecta, Gera- 
nium guatemalense, Huperzia crassa, Isoétes storkii, Lobelia irazuensis, Lupinus cos- 
taricensis, Luzula denticulata, Melpomene moniliformis, Muehlenbeckia tamnifolia, 
Myrrhidendron donnellsmithii, Myrsine dependens, Orobanche minor, Pernettya pros- 
trata, Rumex acetosella, Senecio oerstedianus, Trisetum tonduzii, Ugni myricoides, 
Vaccinium consanguineum, and Valeriana prionophylla. 
At about 750 m, the Caribbean slope of the Cordillera Central shares much with the 
adjacent wet lowland forests. The elevational band beginning at approximately 750 m 
and continuing up to 1250 m is a transitional zone, with a correspondingly attenuated 
mixture of both lowland and montane elements. Various studies (Hartshorn & Peralta, 
1988; Boyle, 1996; Lieberman et al., 1996; Wattenberg et al., 1996) have documented 
the presence of lowland species up to as high as 1000 m; some such species are Calo- 
phyllum brasiliense, Casearia arborea, Couepia polyandra, Dussia macroprophyllata, 
Guatteria diospyroides, G. recurvisepala, Hernandia didymantha, Ilex skutchii, Inga 
sapindoides, Pterocarpus hayesii, Vochysia allenii, and V. ferruginea. Also abundant at 
this elevation are the arborescent palms Euterpe precatoria, Geonoma edulis, Iriartea 
deltoidea, and Prestoea acuminata. According to altitudinal transect data (Boyle, 1996; 
Lieberman et al., 1996), tree ferns (including such species as Alsophila imrayana, 
A. polystichoides, Cyathea caracasana, C. delgadii, C. nigripes, C. onusta, C. wend- 
landii, and Dicksonia sellowiana) become more diverse and abundant beginning 
around 750—1000 m elevation. At 1000—2000 m, such important or rare species as Ilex 
chiriquensis, Magnolia poasana, Matudaea trinervia, Meriania phlomoides, Mette- 
niusa tessmanniana, Quercus bumelioides, and Ticodendron incognitum have been 
found. Toward the summits (2600-2750 m), other species are dominant, including Ar- 
disia pleurobotrya, Brunellia costaricensis, Cavendishia bracteata, Drimys granaden- 
sis, Ilex lamprophylla, I. vulcanicola, Oreopanax xalapensis, Schefflera rodriguesiana, 
Vaccinium poasanum, Viburnum venustum, Weinmannia fagaroides, and W. pinnata. 
The diversity recorded by Lieberman et al. (1996) in 1 ha plots (individuals = 10 cm 
DBH), along an elevational transect (100—2600 m) between the La Selva Biological 
Station and Volcan Barva, varied from 115 species and 45 families at the lowest ele- 
vations to 29 species and 19 families at the highest elevations. The greatest diversity 
was found from 300 to 500 m, with 149 species in 55 families and 131 species in 55 
families, respectively. Meanwhile, Boyle (1996), working in the same region and 
using plots of 0.1 ha (10 transects of 2 < 50 m, individuals = 2.5 cm DBH) in an alti- 
tudinal transect of 5|00—2750 m, found diversity to vary from 118 species in 51 fam- 
ilies at the lower end to 24 species in 17 families at the higher end. Boyle recorded the 
greatest diversity from 750 to 1000 m, with 128 species in 52 families and 133 spe- 
cies in 53 families, respectively. Even though the results of these two studies are not 
directly comparable (because of the differences in size of the sampled areas), it is 
worth noting that the numbers of families and species found between 500 m and 
2600—2750 m were not markedly different. These results are also concordant with 
