* * * * * A Synopsis of the Palms of Puerto Rico. BY O. F. COOK. [Reprinted from the BULLETIN OF THE TORREY BOTANICAL CLUB, 28. Oct., 1901.] * * * * * A Synopsis of the Palms of Puerto Rico BY O. F. COOK (WITH PLATES 43–48) The following systematic notes have been accumulated in connection with economic studies of Puerto Rico[1] palms, and although the list is doubtless still incomplete, the printing of it may be justified as a means of securing at least provisional names needed for reference purposes in connection with other publications of a non-systematic character. The palms may well be considered a very refractory group when handled by the conventional methods of systematic botany. Difficult at once to collect or to study from dried material, they are commonly neglected both in the field and in the herbarium, with the result that literature is scanty and unsatisfactory. A very large proportion of the descriptions are entirely inadequate for the identification of species, and there has been much lawlessness and diversity in the application of generic names, as will appear from some of the instances discussed below. Difficulties of description and classification have also been multiplied by the fact that the palms are such peculiar plants that analogies and criteria borrowed from other families are often inapplicable and misleading. Moreover, the terminology of parts and characters has not been developed to the point where the expression of observed differences is easy, and available language often fails completely to suggest the significance of the characters used. Thus the fibers into which parts of the leaf-bases of many palms are resolved afford many diagnostic characters, for which we have no parallels in other groups of plants. A compensating advantage may be drawn, however, from the definite and often very limited geographical distribution of the species of palms. Thus, although Puerto Rico is a relatively small island, several of the indigenous palms have apparently ranged in nature over but a small part of it, and a locality definitely indicated would often go further toward establishing the identity of a species than much of the descriptive matter prepared for this purpose. For the present, at least, the geographical idea should be kept uppermost in systematic studies of the palms, since it is generally much easier and far more logical to extend the limits of supposed distribution and unite supposed species, than to cope with the confusion caused by the miscellaneous reporting of species far outside their natural ranges.