Manual de Plantas de Costa Rica 237 
Abutilon giganteum, Bonamia trichantha, Colubrina heteroneura, Ocotea aurantio- 
dora, Pera oppositifolia, and Porcelia magnifructa. 
Recent explorations in the southern Fila Costefia, in the Coquito, Anguciana, Cru- 
ces, and Zapote ridges, have resulted in at least 11 additions to the Costa Rican flora, 
of which the following seven are new records: Aiphanes hirsuta, Asplenium soleirolioides, 
Dennstaedtia sprucei, Diospyros panamensis, Gonocalyx megabracteolatus, Joosia 
umbellifera, and Manettia microphylla; all of these have southern origins, except for 
Asplenium soleirolioides, from Mexico. The four new species are Dalechampia burge- 
riana*, Ocotea patula*, Peperomia hammelii*, and P. trichomanoides*. This coastal 
side of the southern Fila Costefia has been poorly collected and needs further work. 
The Golfo Dulce region, especially the Osa Peninsula, was visited several times be- 
tween 1890 and 1901 by such botanists as Henri Pittier, Adolphe Tonduz, and Carroll W. 
Dodge, in 1948 by Alexander Skutch, and later by Paul H. Allen, among others; see the 
chapters on History and Vegetation for more details. Beginning in the years 1984-1989 
(within the time-frame of the present discussion), more intensive and constant explo- 
rations were undertaken, much improving our database for this important floristic re- 
gion. This activity has contributed a total of at least 116 species new to Costa Rica, in- 
cluding 57 new to science (52 of which are still considered endemic). 
This outstanding harvest of novelties demonstrates that the Golfo Dulce region is of 
great diversity and scientific interest. Close analysis of the discovered species also rein- 
forces the concept, already put forth for the Osa Peninsula by Hartshorn (1983) and for 
the entire country by Standley (1937b), of a close relationship to the flora of South 
America. Of the 59 new country records, 70% are presumably from South America, 
many more than the 20% hypothesized by Gémez P. (1986: 231); an additional 19% are 
from between Mexico and Nicaragua, 10% from Panama, and 1% from the Antilles. Cu- 
riously, the phytogeographic relationships indicated by this subset of species from Osa 
are more with South America than with nearby Panama (see also below). 
Among the phytogeographically most interesting novelties from the Osa Peninsula 
are Ruptiliocarpon caracolito (see beginning of this chapter), and a new species of 
Pleodendron, the first record of the family Canellaceae for Central America, augment- 
ing the Antillean relationship. Other widely disjunct taxa first found in Costa Rica on 
the Osa Peninsula (with their previously known distribution) include Dicella (South 
America), Oecopetalum greenmanii (Mexico, Guatemala), Parabignonia (South Amer- 
ica), Paullinia tenuifolia (South America), Recchia simplicifolia (Mexico), Williamo- 
dendron (Brazil, Colombia), and Ziziphus chloroxylon (Jamaica). 
Conclusion 
Evaluating the previously known distributions of at least these 361 new (accumulated 
over the last ca. 15 years) reports reaffirms the South American affinity of the Costa Rican 
