Part 8

Leaves about 2 m. long, the pinnae lanceolate, equally spaced and lying nearly horizontal, 55 cm. long and 4 cm. broad; the surface light green on both sides, with very close parallel longitudinal veinlets, but no visible cross veins. The sheathing bases are considerably shorter and generally appear somewhat more robust than in Roystonea. In protected situations the leaf-bases persist and the margins shrivel up and expose a flimsy network of fibers. Inflorescences appearing several close together; by the falling of the leaves above them they are left several inches below the leaf-bases before maturity is attained. Spathes fusiform, long, more slender and pointed than in Roystonea. Spadix once-branched, 1 m. long, 6 cm. in diameter at base, tapering gradually to the apex. Branches 23 cm. long and less, the proximal branches longest; at first appressed to the rachis, the branches are opened out and held stiffly erect by a fleshy turgid cushion on the upper (distal) side of the base of each. The branches of the rachis may thus be said to be hinged, and with maturity the supporting cushion dries away and allows them to resume a direction nearly parallel to that of the rachis.

The dried fruits of Acrista are grayish brown in color and nearly smooth or somewhat coriaceous in external texture; they measure 11 or 12 mm. in length and are nearly as wide, being slightly oboval in shape. The outer wall is thin and brittle and covers a more or less distinct thin layer of amorphous brownish material probably representing the pulp of the fresh fruit; in the dry state this may adhere either to the outer wall or to the fibers next inside. Near the base these fibers are simple, pointed and vertical; about half way up they divide and anastomose and are, as it were, felted and cemented together to form an oval sac open below and closed above. The outer fibers are much coarser than the inner and there are sometimes suggestions of three layers separated by a dark-brown friable material. A few of the delicate inner fibers are adnate to the surface of the seed which is otherwise free from its fibrous covering.

Seed 8.5 mm. by 8 mm., slightly lighter in color than the outside of the fruit. Surface slightly uneven with obscure veinlike ridges and impressions of the fibers of the outer covering. The kernel is white, hard and bony, and deeply ruminate, though this is not apparent from the outside. The channels are very narrow and often radial and straight; they penetrate 3 mm. or less. Embryo directly basal; hilum lateral, somewhat below the level of the stigma; a short raphe extends about half way to the embryo.

Family COCACEAE

The cocoid palms are a distinctly American group, the African oil-palm, Elaeis Guineensis and the cocoanut being the only outliers of the family which have been supposed to be indigenous in the Old World. South America is the center of distribution and is the home of a large proportion of the two hundred or more species. Only five genera reach Puerto Rico, and one of these, Cocos, was probably not a native of the island.

Key to the Subfamilies of Cocaceae

Trunks, stems, and midribs beset with sharp spines; seeds foraminate at or above the middle.

Subfamily BACTRIDINAE.

Trunks and other parts unarmed; seeds foraminate at base.

Subfamily COCINAE.

Subfamily BACTRIDINAE

Some of the numerous South American representatives of this group are nearly smooth, but the three genera known from Puerto Rico have the trunks, leaf-bases, midribs and inflorescences beset with sharp black spines, and are thus readily recognizable.

Key to the Genera of Bactridinae

Trunk small, cespitose; leaves separated by long internodes; foramina of seeds apical.

BACTRIS.

Trunk medium or large, solitary; leaves crowded together at the summit; foramina peripheral.

Trunk slender; leaf-divisions broad, praemorse-truncate; pistillate and staminate flowers intermixed on the inflorescence; exocarp fleshy.

CURIMA.

Trunk robust; leaf-divisions narrow, sharp-pointed; pistillate flowers below and separate from the staminate; exocarp fibrous.

ACROCOMIA.

BACTRIS Jacquin, Stirp. Am. 279. pl. 271. 1763

The type of this genus, Bactris minor Jacquin, described from the vicinity of Carthagena, Colombia, is a small spiny palm with creeping rootstocks. The upright trunks are about an inch thick and twelve feet high, with long spiny internodes. The fruits are fleshy, purple, and about the size of a cherry. Several species of Bactris are known from the West Indies though the generic name has doubtless been applied rather loosely to all the small spiny cocoid palms.

The two following species of Bactris from Puerto Rico described by Martius several decades ago seem not to have been secured by recent collectors unless it be true, as suggested below, that one of them, the simple-leaved B. acanthophylla applies to a young Curima. Of B. Pavoniana the narrowly grass-like leaf-divisions would be sufficiently characteristic to separate it at once from all other palms known from Puerto Rico.

BACTRIS ACANTHOPHYLLA Martius, Palm. Orbign. 67

“Trunk low, spiny; frond simple, the petiole spiny; blade lanceolate in young plants, oblong in the adult, cuneate at the base and bifid at apex, the margin unequally erose, unarmed; rachis and primary veins spiny on both sides; spines bristle-like, narrowed at base, those of the petiole black, those of the blades fuscous.”

“In the western part of the island of Puerto Rico, near the village of Yrurena, in swampy places on the margins of aboriginal forests at an altitude of 400 feet; collected by Wylder, 1827.” (Martius Hist. Palm. =3=: 281.)

A specimen to which the above diagnosis would not be inapplicable was collected by Sintenis in the mountain forests near Maricao (no. 484). It was distributed from Berlin as a Martinezia, together with two other very young plants and a seed to which one of these was attached.

The seed evidently did not come from a cocoid palm but together with the young seedlings may belong to Acrista. The large spiny plant is probably a young specimen of Curima, and should these suggestions prove to be correct the specific name acanthophylla must be transferred to this genus though whether it will replace colophylla or not is not to be determined until it can be ascertained that the Maricao species is the same as that here described from Bayamon.