168 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
resistance to the wind by being split down the middle. The leaves of Inodes, 
which are held horizontal from an erect axis, have attained the unique adaptation 
of a decurved midrib which braces the sloping sides of the leaf and effectively 
prevents the breaking above the ligule common in some of the species of Thrinax. 
It is true that the palm-leaf hats manufactured in large quantities in Porto Rico 
are made from the present species. The center of the hat industry is at Joyua, a 
small village on the western coast of the island some miles southwest of Mayaguez 
and west of Cabo Rojo. Here many hundreds of the palms are growing along 
the shore in a narrow belt of coral sand. 
Ipecac. 
See note under Asclepias curassavica. 
Ipomoea acetosifolia. See Ipomoea carnosa. 
Tpomoea batatas. SWEET POTATO. BATATA. 
In Porto Rico the sweet potato is found in all sorts of places, particularly at low 
elevations, often appearing quite wild, though in a country where such general 
and yet desultory agriculture has been carried on it would be very difficult to 
demonstrate the indigenous character of the plant. It seems, however, that the 
potato was cultivated in the West Indies before the advent of Europeans, but 
that does not necessarily involve an indigenous origin, since it was probably 
already spread throughout tropical America. Moreover, like the cocoanut. it 
seems to have crossed the Pacific and reached China in the second or third cen- 
tury. Some writers have believed in the Asiatic or Malayan origin of the plant, 
and have claimed that batata is a Malay name, though this is not the prevailing 
idea, the present tendency being to consider not only batata but also ‘‘ camote.”’ 
the Philippine name as of American origin, and probably introduced from Mexico 
by the Spaniards. 
Little attention is paid in Porto Rico to the planting of pure or high-grade 
stock, and propagation is carried on exclusively from the vines, pieces a foot long 
being buried for half their length in the ground. When regular culture is 
attempted the cuttings are placed a foot apart in rows 2 feet apart. The weeds 
are sometimes kept down and the rows hilled up, but often neither of these mat- 
ters is attended to. The crop is not dug at any regular time, but individual roots 
are discovered by probing and taken out without otherwise disturbing the vine, 
which is permitted to grow indefinitely. 
Numerous varieties are grown in every patch, to judge from the very different 
leaf forms. The red sorts have lobed leaves, while those of the white kinds 
(batata blanca) are simply cordate or nearly circular. For good crops rich land 
is necessary, and the red clay soils seem to be very suitable. Four tons per acre 
is quoted as a good crop, but a second crop may be secured a month or six weeks 
later. In the eastern end of the island and in Vieques there is said, for some 
unexplained reason, to be a scarcity of sweet potatoes, so that with the regular 
demand a local market is open to those who might undertake this culture on a 
commercial scale. At the time of our visit retail prices were 3 or 4 centavos per 
pound in the city markets. 
Ipomoea biloba. BrJUCO DE PUERCO DE PLAYA. 
(Stahl, 6: 160.) 
Ipomoea bona-nox. BEJUCO DE VACA. 
An annual ornamental vine growing to great length and bearing many large 
flowers. Bello gives the name ‘* bejuco de puerco’’ for Calonyction megalocarpon. 
(Stahl, 6: 148.) 
Ipomoea carnea. BATATILLA CARNOSA. 
A large vine found along the coast. (Stahl, 6: 277.) 

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