Trunk 45–75 cm. thick at base, 5–15 m. tall, columnar or slightly tapering upward; surface narrowly rimose or nearly smooth, light gray or nearly white. Leaf-bases splitting into rather brittle fibers, partly remaining compacted into long ribbons 5–8 cm. wide. Leaves about 4 m. long, the petiole subequal to the blade, considerably exceeded in length by the inflorescence. Petiole 3.8 cm. wide, distinctly carinate above near the end; ligule 4.2 cm. in diameter. Fruit grayish, 9–10 mm. in diameter; seed chestnut-brown, finely rugose or nearly smooth, 7–8 mm. in diameter; embryo oblique, at an angle of somewhat less than 45 degrees from the horizontal. Type specimen from Joyua (no. 154). The palm-leaf hats manufactured in large quantities in Puerto 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. From the two species of _Sabal_ recognized by Grisebach _Inodes causiarum_ differs from _umbraculifera_ in having the inflorescence much longer than the leaves, while the trunk and leaves are much shorter and thicker than in _Sabal mauritiiformis_ a native of Trinidad and Venezuela which appears from Karsten’s figure, reproduced in the Natürlichen Pflanzenfamilien, to have neither the leaves nor the habit of an _Inodes_ though there is no other genus to which it can be referred with greater propriety. The diameter of the trunk of the Trinidad palm described as _S. mauritiiformis_ is given as from 12 to 15 inches, while _I. causiarum_ is often two feet or more thick. From the Florida palmetto, =Inodes Palmetto= (_Corypha Palmetto_ Walter, Fl. Carol. 119. 1788) the Puerto Rico species differs most conspicuously in not retaining the old leaf-bases which give the trunk of the Florida palm so rough an appearance. The cause of this difference is doubtless to be found in the fact that as with most other palms the trunk of _I. Palmetto_ grows to full size while the surrounding leaf-bases are still alive, but in the West Indian species the trunk tapers greatly, especially in young trees, and the leaf-bases are torn away by its gradual enlargement to full diameter. The existence in southern Florida of an _Inodes_ having this last characteristic is a fact of much interest recently brought to my attention by Mr. E. A. Schwarz, of the U. S. Department of Agriculture. The specific distinctness of this palm was impressed upon Mr. Schwarz, not only by its naked trunk, different habit, and smaller size (5 m., instead of 10 to 20 m.), but also by the possession of a distinctly tropical insect fauna, quite different from that of the more northern palmetto with which he had previously been familiar.[2]