206 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Olea europaea. OLIVE. ACEITUNA. 4 
Olive culture is one of the new industries which has been suggested for Porto 
Rico. The olive is native to the dry climate of the desert regions about the Medi- 
terranean. It has also been successfully introduced into similiar situations in 
southern California and Arizona. In Florida, however, owing doubtless to the 
more moist atmosphere, the production of fruit has been found impossible, although 
the trees vegetate with apparent vigor. Under the more tropical conditions of 
Porto Rico, with a warmer and more moist atmosphere, there is still less probabil- 
ity of the production of fruit, to say nothing of securing it in commercial quan- 
tities and of superior quality, as would be necessary in order for it to become an 
export crop able to compete with established industries. An experiment in the 
driest localities on. the south side of the island might be worth while from the 
scientific standpoint, but the general planting of olives in the hope of establishing 
an industry which might be substituted for those now in distress could result 
only in more complete disaster. 
Oleander. See Nerium oleander. 
Olive. See Olea ewroped. 
Olive mangrove. See Avicennia nitida 
Onion. See Allium cepa. PuaTe XLVIUII. 
Opuntia. 
A large genus of Cactaceae, with numerous representatives in Porto Rico. About 
Guayanilla the members of this genus are very abundant, forming almost a forest 
in some places. 
Opuntia coccinellifera. See Nopalea coccinellifera. 
Opuntia decumbens. OTAGA. 
A cactus abundant on the southern and eastern coasts. (Stahl, 4: 190.) 
Opuntia guanica. 
A small indigenous species recently described by Professor Schumann, of Berlin. 
Opuntia repens. 
Known from near Guanica. 
Opuntia tuna. TUNA BRAVA. 
The identity of this cactus seems to be very uncertain.. Some botanists have 
confused it with the species usually called Opuntia ficus-indica. 
Orange, Wild. See Naranjo. 
Mr. Hill says the wild or Seville orange in the country is an indigenous tree. 
Numerous seedling varieties of oranges and other citrus fruits have escaped from 
cultivation and are to be found in unexpected places in all parts of the island. 
No species of citrus is, however, supposed by botanists to be indigenous in Porto 
Rico or in any part of the American continents or islands. 
Orchata. 
A drink said to be made from the ‘* sweetened and diluted milk of almonds.” 
In view of the prevalent belief that the nuts of Terminalia catappa are ‘* almen- 
dras,’’ this statement should probably be understood as referring to that species 
rather than to imported nuts. 
Oreganillo. See Eupatoriwm villosum. 
Oregano. 
Leaves sold in the market of Ponce; used for seasoning food. > 
Oregano brujo. See Coleus aromaticus. 
Oregano de Espana. See Coleus aromaticus. 
Oregano del pais. See Lippia micromera. 
Oreodoxa. See Roystonea. 
