A synopsis of the palms of Puerto Rico

by O. F. Cook

The second of the original species of Oreodoxa is now referred to the genus Catoblastus. It is a somewhat smaller tree from 12 to 15 metres high, with a generally similar habit, and is also stoloniferous, but the pinnae are broad, cuneiform and praemorse, or irregularly truncate as in the species generally referred to Martinezia. The drupaceous fruit is grayish and the pulp is only slightly succulent; seed the size of a pigeon’s egg, its exterior brown, marbled with numerous veins. In the characters of the spathe the arrangement of the fruit and the edible quality of the heart of the leaf-cluster, as well as in the formation of lateral off-shoot this species is said to be similar to the first.

Botanists are not yet agreed upon the methods of dealing with complications like the present in regard to the names of plants, but it appears certain that those who do not recognize Oreodoxa as a genus distinct from those admitted in the more recent works on palms must associate it either with Euterpe or Catoblastus. The latter name it would in that case replace, being much older. Moreover, unless we are prepared to disregard Willdenow’s statements concerning the stoloniferous trunk, the simple spathe and the hermaphrodite flowers, to say nothing of many minor points of circumstantial evidence, there is no scientific warrant for applying the name Oreodoxa to the noble Antillean species with which it has been universally associated.

The dried specimens which Willdenow studied were supplemented by notes of field observation by a court gardener, who was evidently also a botanist of some experience, to whom Willdenow refers as his “friend.” The living colors are described with considerable detail throughout the entire paper, which renders noteworthy the fact that the spathes are stated to be cinereous. This is in agreement with species of Euterpe which have membranous spathes, but indicates a wide difference from the West Indian trees where the spathes are thick and fleshy and remain vivid green until they open and fall away.

The name Roystonea has been given to this ornament of the Puerto Rico landscape as a respectful compliment to General Roy Stone, the American engineer officer who secured the admiration of the people of Puerto Rico by his fearlessness and conspicuous energy in the Adjuntas road-building campaign which flanked the line of Spanish defenses, and whose subsequent interest in the improvement of the island will undoubtedly affect its future history.

Roystonea Borinquena sp. nov. Plate 45. f. 2.

Trunk normally fusiform, 30–60 cm. thick, 12–18 m. high. Leaf segments 4–4.4 cm. in width. Inflorescence robust, compact, twice branched, the branches numerous and coarse, ferruginous, pubescent. Fruits long-oval, yellowish brown at maturity. Seeds 8 mm. by 6.3 mm., flattened about the hilum, rounded below; wall of endocarp smooth, adherent over a small area.

The royal palm of Puerto Rico differs from that of Cuba in having the trunk generally shorter, more robust and more distinctly fusiform. The inflorescence is twice branched, with the branches more densely clustered, coarser and darker colored than those of the Cuban royal palm, Roystonea regia. They are also covered with a slightly hispid brown pubescence while Cuban specimens are much smoother and more pallid. The difference of habit, to judge from photographs of the Cuban species, is most apparent when the trees have grown in the open, as when planted in avenues or along roadsides. In Puerto Rico, trees which are obliged to compete with other vegetation are often tall, slender and unsymmetrical. The typical form is shown in our photograph (no. 250) taken in the plaza of Juana Diaz.

Martius gives the width of the pinnae of the Cuban royal palm as from 8 to 12 lines. Cuban specimens show as much as one inch and a quarter, while others from Porto Rico are half an inch wider (44 mm.) of somewhat coarser texture and with more widely separated secondary veins. The fruits of the Puerto Rico palm are a deep yellowish brown when ripe, while those of the Cuban are said to become violet or bluish black. According to Martius, the fruits of the Cuban species are 6 lines by 4, but dried specimens show no such discrepancy of proportions and measure only about 8.5 mm. by 7.5 mm.

In Puerto Rico the fresh fruits are also much longer than broad, perhaps even more slender than the figures given for the Cuban; when dry they still appear somewhat longer and larger than the latter.

The seeds of Roystonea Borinquena differ in several particulars from those of the Cuban species. In shape they are longer and less spherical, measuring 8 by 6.3 by 5.5 mm. instead of 7.8 by 7 by 6 mm.; the side bearing the hilum is much flattened and even slightly concave; the fibers radiating from the hilum are longer, and the corner between the hilum and the micropyle is evenly rounded, not sharply squared and prominent as in R. regia. On the back of the seed the smooth inner wall of the endocarp is closely adherent over a small area, while in Cuban seeds this wall remains attached over nearly the whole side and is furthermore distinctly rugose-coriaceous on the surface, and has a distinct sulcus in the median line.