COOK AND COLLINS—ECONOMIC PLANTS OF PORTO RICO. 269 
Jamaican natives until machines can be invented to replace the hand labor 
required in peeling andcuring. Abrasion in arotary drum is described by Semlar 
as in use in the West Indies, but there is no indication of any general adoption of 
this method of curing. 
Planting takes place in Jamaica in March and April, the ends of the “‘ fingers ”’ 
bearing the terminal buds being buried in holes or trenches 2 or 3 inches (50 to 
75 millimeters) deep, and 12 to 18 inches (30 to 45 centimeters) apart. Shade is not 
necessary. and all weeds should be removed, though it is considered bad policy to 
disturb the ground after the plants have reached any considerable size. Blossoms 
appear in September, and harvest extends from December to March. The root- 
stocks should not be dug until the plant has withered, and they can without det- 
riment be left in the ground for a considerable period after ripening. 
Zingiber zerumbet. BITTER GINGER. GENGIBRE AMARGO. 
The different species and varieties of ginger have given systematic botanists no 
little difficulty, and there is still much uncertainity and confusion. There seems, 
however, to be no reason why the plant called ‘‘ gengibre amargo’”’ or “‘ bitter 
ginger’ by the Porto Ricans should not be referred to Z. zerumbet, although no 
flowers were seen. - The rootstock is much larger, thicker, and more cylindrical 
than the genuine ginger; the taste is rank and bitter, with but little of the true 
ginger flavor. The Porto Ricans look upon it as a medicine rather than as a spice 
and use it mostly in the form of a tincture with rum, both as an external and as 
an internal remedy. 
Zizyphus reticulata. AZUFAIFO. 
Family Rhamnaceae; a smooth shrub, 2 2 to 3 meters high, found in limestone 
rocks. (Stahl, 4: 32.) 
Zornia diphylla. ZARZABACOA DE DOS HOJAS. 
Family Viciaceae; an herbaceous annual, reclining or diffuse, in sandy pas- 
tures. Common to all tropical America. (Stahl, 3: 84.) 
O 
