12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 98 



customary descriptive terms and expressions are applicable only with 

 special meanings, and may prove misleading unless the actual features 

 can be illustrated, preferably by photographs. 



The Cocos Island palm is related rather closely to Plcctis owcniana 

 Cook, discovered in mountain forests of eastern Guatemala in 1902 

 and briefly described in the Bulletin of the Torrey Botanical Club, 

 June 1904. The specimens of Plectis preserved in the United States 

 National Herbarium include entire inflorescences and spathes, with 

 several photographs taken in the type locality, so it is possible to 

 illustrate several features for comparison with the new genus. Two 

 species described under Euterpe, by Oersted from Costa Rica in 1858, 

 E. macro spadix and E. longipetiolata, are well represented in the 

 Herbarium. They are small, slender palms, with ruminate seeds and 

 simple-leaved seedlings, related to Acrista but not to Plectis or to 

 Rooscveltia. 



A COMPARISON OF ROOSEVELTIA AND PLECTIS 



HABIT AND TRUNK CHARACTERS 



Though sharing many of the characters of Plcctis, the Cocos 

 Island palm is of more robust habit, with a thicker trunk and shorter, 

 broader internodes, much wider than long, whereas the trunk of 

 Plectis is more slender, with internodes often much longer than wide, 

 sometimes twice as long. The base of the trunk is rather abruptly 

 thickened, instead of tapering gradually as in Plectis, the leaf-sheath 

 bundle is thicker, the stalk or petiole of the leaf is much shorter, and 

 the rachis or midrib notably longer. The trunk is supported on a mass 

 of coarse roots, 2 cm. or more in diameter, usually not appearing 

 above the surface, but the lower side of the root mass is sometimes 

 exposed on steep slopes of tenacious clay soil, as shown in plate 4. 



A rather young palm, 25 or 30 feet high, was measured by 

 Dr. Schmitt, 45^ inches around the thickened base of the trunk, and 

 20^ at 2 feet above the base ; but notably larger palms were seen, so 

 that a diameter of 40 cm. or more is indicated, rapidly narrowing 

 to about 20 cm. and then narrowing very gradually to 12 or 13 cm., as 

 shown by sections from the top of the trunk, with inflorescences still 

 in place. The trunk of Plectis tapers much more gradually from the 

 base, and becomes much more slender at the top. 



The gradual thickening of the trunk is a feature that most of the 

 palms do not share, the function of secondary growth being recog- 

 nized only in the exogenous, bark-bearing plants, that have a special 

 layer of cambium tissue for forming new wood. Although the trunk 



