This noble palm has the stem fifty or sixty feet high, straight, cylindrical and nearly smooth. The leaves are very large, terminal and regularly pinnate. The leaflets are elongate, rigid, closely set together, and spreading out flat on each side of the midrib. The sheathing bases of the petioles are persistent for a greater or less distance down the stem, and in young trees down to the ground, as in the _Œnocarpus batawá_. The spadices grow from among the leaves and are large and simply branched. The fruit is of large size compared with most American palms, being about three inches long, and from this circumstance it derives its native name “Uauassú,” signifying “large fruit.” The foliage of this tree is very extensively used for thatching. The young plants produce very large leaves before the stem is formed, and it is in this state that they are generally used. The unopened leaves from the centre are preferred, as, though they require some preparation, they produce a more uniform thatch. The leaf is shaken till it falls partially open, and then each leaflet is torn at the base so as to remain hanging by its midrib only, which is however quite sufficient to secure it firmly. They thus hang all at right angles to the midrib of the leaf, which admits of their being laid in a very regular manner on the rafters. They are generally known as “palha branca” or “white thatch,” from the pale yellow colour of the unopened leaves, and are considered the best covering for houses in places where Bussú cannot be obtained. This species grows on the dry forest lands of the Upper Amazon. On the Rio Negro a stemless species called “Curuá” (_Attalea spectabilis_) is found and is often used for thatching. On the Lower Amazon and in the neighbourhood of Pará the _Attalea excelsa_ is not uncommon. It is a handsome lofty species which grows on lands flooded at high tides, and is called by the natives Urucurí. The fruit of this tree is burnt, and the smoke is used to black the newly made india-rubber. Martius says that the fruit of the _A. speciosa_ is used for this purpose, but that species is not found in the principal rubber districts, while the _A. excelsa_ is abundant there. Several species of _Attalea_ are cultivated in the Palm House at Kew. Plate III. fig. 1. is a fruit of _Attalea spectabilis_ of the natural size. Genus MAXIMILIANA, _Martius_. Some spadices with only male flowers, others with . male and female flowers on the same tree. Spathes large, complete, woody. Flowers with bracts. Male flowers with three or six stamens, and with a minute rudimentary pistil. Female flowers with a short style and three stigmas, and rudimentary stamens forming a membranaceous cup.