Monographs Details: Nectandra
Authority: Maguire, Bassett & Wurdack, John J. 1964. The botany of the Guayana Highland--Part V. Mem. New York Bot. Gard. 10: 1-278.
Family:Thymelaeaceae
Scientific Name:Nectandra P.J. Bergius
Discussion:

Since delimitation of this genus has been the focal point of much discussion for the past century, it seems appropriate at this time, before treating the species involved in the area here under consideration, to mention briefly two of the most controversial species complexes concerned. The first centers about Nectandra cuspidata and N. pichurim; the second about Nectandra globosa and N. pisi. At present, only tentative suggestions can be made which we can only hope to have clarified when conscientious effort has been made to obtain collections of fruiting material from the areas where these species grow profusely and from which collections have so far been made almost entirely in the flowering stage.

First, the cuspidata-pichurim complex. After examination of as much of the type material and collections from the type localities as are available, with close attention to field notes and published comments, the following suggestions are offered. Except for the fact that there are a few scattered fruiting specimens extant, even a distribution pattern and separation as tentative as the following could scarcely be presented. It goes without saying that further collections from the critical areas under consideration will undoubtedly necessitate a change in the present interpretation of the distribution of the species, as well as of the current delimitations of species and genus.

There appear to be two species, at least, similar in branching and leaf habit, which share a common flower structure, namely, having stamens of the first and second series with anthers broader than long, their cells in the arcuate arrangement usual for Nectandra and occupying almost entirely the anther structure, with little or no connective tissue apparent. Also, specimens with seemingly identical branching and foliage habits are known to mature two types of fruit, not distinctive in shape, but in their relation to the cupule subtending them, and in the shape of the cupule itself. These, from study of available fruiting material, are represented by N. cuspidata and N. pichurim, both occurring in the Guayana area; these are discussed below.

Brief mention only should be made here of two additional species closely related to the above-mentioned critical taxa: Nectandra membranacea Grisebach from the West Indies exclusive of Trinidad and Tobago, which bears globose, totally exserted fruits subtended by a very shallow, disklike cupule, seated on a much more coarsely enlarged obconical pedicel than that found in the cuspidatapichurim species; and Necta,ndra gentlei Lundell chiefly of Central America, more closely allied with the current concept of N. cuspidata than any of the plants under discussion. Nectandra gentlei bears ellipsoid fruits, larger than those found in the three taxa last mentioned, and borne totally exserted on shallow cupules. Leaf characteristics of all four species m a y vary, but the flower structures remain more or less consistent with only minor deviations apparent.

Apparently associated with the Nectandra cuspidata-pichurim complex through leaf and branching habit, specimens have been collected from regions of tropical South America other than the Guayana area that show a second type of flower considered to be representative of the Nectandra globosa-pisi complex. The typical, more or less triangular, exceedingly fleshy, usually papillose anthers have a protruding connective of varying length. These specimens are mentioned in this connection merely to bring attention to a second type of floral characteristic which in other features has an affinity to the complex discussed above.

The second critical group indicated, the Nectandra globosa-pisi complex, will be taken up only briefly in proper sequence, no attempt being made at present to resolve it. Until a thorough monographic study is under way, neither of these areas of the genus can be satisfactorily clarified. Needless to say, such a treatment will necessarily involve a concerted effort on the part of field workers to re-collect in critical type localities both flowering and fruiting materials, preferably from marked trees. This work has already been outlined and it is hoped may be continued. It goes without saying that since intermediate stages of floral structure occur, a study of Nectandra must involve a concomitant treatment of the genus Ocotea as well and the "fringe" genus, Pleurothyrium, the latter heretofore thought to be restricted to the Amazonian area, but which perhaps may be far more widely distributed. Then and only then can a re-evaluation of generic delimitation be undertaken with hope of a satisfactory and acceptable conclusion. The following discussions and descriptions must rest on the study of the inadequate materials currently available in herbaria.