A contribution to the wood anatomy of South American (Chiefly Suriname) Rubiaceae. I

A general description of the structure of the wood of the Rubiaceae is given, based on examination of samples from most subfamilies. The results of the author’s investigation are compared with the data in the literature. The features of vessels, rays, and parenchyma agree well with those reported by other investigators. When the fibres are divided into libriform fibres and fibre tracheids in the sense of Janssonius, the correlation between the distribution of these organs and recent taxonomic subdivisions of the family is better than when all fibres with bordered pits are regarded as fibre tracheids

A contribution to the wood anatomy of the Cinchoneae, Coptosapelteae and Naucleeae (Rubiaceae)

Wood samples of a number of Cinchoneae and Naucleeae sensu Schumann were studied, and the results compared with data found in the literature. On the whole the representatives of the Cinchoneae appeared to show a rather high degree of similarity among each other with the exception, however, of the genera Coutarea, Exostemma, Corynanthe, Crossopteryx, and Hymenodictyon. The creation of the tribe Coptosapelteae and its inclusion in the Ixoroideae seem to be corroborated by the particular character of the wood anatomy. The restriction of the Naucleeae to Nauclea L. ( Sarcocephalus Afzel.) is not supported by the anatomy of the wood

A contribution to the wood anatomy of South American (Chiefly Suriname) Rubiaceae. II

This paper contains a discussion of the taxonomic subdivisions of the Rubiaceae as proposed by Schumann, Verdcourt, and Bremekamp. Generally speaking, the subdivisions as proposed and delimited by Bremekamp agree best with the characters of the wood structure, as observed by the author. Furthermore a key to the Suriname genera is given

Studies in Annonaceae VI. A leafanatomical survey of genera of Annonaceae in the Neotropics

SETTEN, A. K. van & KOEK-NOORMAN, J.: Studies in Annonaceae. VI. A leafanatomical survey of genera of Annonaceae in the Neotropics. — Bot. Jahrb. Syst. 108: 17—50. 1986. — ISSN 0006-8152. Within the scope of the multidisciplinary research project on systematics of Annonaceae, a survey of the leafanatomical features and their distribution in the neotropical Annonaceae is presented. The studied specimens form a rather homogeneous group, as may appear from the family description given here. A detailed study of the leafanatomical features reveals, that differences are mainly found in the indument, the position and contents of the idioblasts, the structure of the primary vein, the type of crystals in the epidermal cells, and the type of sclereids. Based on character states, phenetic similarities and differences are discussed and compared with the classifications of FRIES (1959) and WALKER (1971)

The anatomy of branch abscission layers in Perebea mollis and Naucleopsis guianensis (Castilleae, Moraceae)

The shedding of branches along a preformed layer is a complex phenomenon in which several types of xylem elements are involved. The abscission layers in Perebea mollis and Naucleopsis guianensis are distinguished from the normally developed xylem by the presence of shorter unlignified fibres with small simple pits. Most of these fibres show large nuclei. In this zone containing abnormal fibres, the vessels, rays and parenchyma are conspicuously different from those of the normal tissue. The transition in anatomy from the main branch to the abscission layer is much more abrupt than that from the abscission layer to the secondary branch. Contrary to what is generally seen in other Moraceous tribes, natural pruning seems to occur in all genera of Olmedieae with the sole exception of the genus Olmedia. The correlation with other morphological and anatomical characters and the complexity of the phenomenon of branch abscission seem to justify Berg’s decision to use this character in defining the new tribe Castilleae, containing all the genera formerly placed in Olmedieae except Olmedia