Search

The mating behavior of M. angulata (Fabricius, 1775) is described, illustrated and discussed. Additionally, we also comment on the possible new host plant of this species based on two plants (Luehea cymulosa Spruce ex Benth. (Malvaceae) and Doliocarpus dentatus (Aubl.) Standl (Dilleniaceae) on which copulation occurs. © 2020, Universidade de Sao Paulo. All rights reserved.

The generic name Burtonia Salisb. was validly published in 1807 and based on the species now known as Hibbertia grossulariifolia (Salisb.) Salisb., probably the first species from Western Australia to flower in England. Burtonia R. Br. (1811) has been proposed for conservation.

Saurauia veraguensis in Costa Rica is morphologically androdioecious but functionally dioecious. Both staminate and pistillate flowers bear pollen. The pollen in the staminate flowers is tricolporate, and smaller than the inaperturate pollen borne by the pistillate flowers. The inaperturate pollen probably plays a role in pollination by serving as a reward, but it does not germinate on the stigmas and is therefore non-functional in fertilization. Dioecy in Saurauia may have evolved via androdioecy, although other evolutionary pathways such as via gynodioecy cannot be ruled out. Saurauia Willd. (Dilleniaceae) is a large genus of smallto medium-sized trees with approximately 300 species distributed in tropical Asia and America (Willis, 1973). Approximately 65 species occur in the Western Hemisphere from central Mexico to Chile (Hunter, 1966). Taxonomic treatments of the genus imply that the species have perfect flowers (Hunter, 1966). However, Soejarto (1969), in a detailed study of herbarium specimens, found that several species in South America are sexually dimorphic. On the basis of pollen fertility and the size of pistils, he concluded that at least seven species are dioecious and one androdioecious. During the course of our ongoing studies of the reproductive biology of tropical forest plants in Costa Rica, we observed two distinct sexual phenotypes in Saurauia veraguensis, a species not studied by Soejarto. One phenotype appeared to bear only staminate flowers and the other only hermaphroditic flowers, indicating the occurrence of androdioecy. Because androdioecy is presumed to be extremely rare among angiosperms (Charlesworth & Charlesworth, 1978; Bawa, 1980) we investigated the reproductive biology of S. veraguensis. Here we describe the sexual system of S. veraguensis and discuss the evolution of dioecy in the genus. STUDY SITE AND PLANTS Saurauia veraguensis is a small tree, reaching up to 7 m in height. Our field observations were restricted to two populations; one was on the Pacific face of the Cordillera de Tilarafn in the Monteverde cloud forest and the other on the Atlantic slopes of the Volcan Poals, both in northwest Costa Rica at an elevation of 1,500 to 1,600 m. Holdridge et al. (1971) characterized the vegetation of these areas as Lower Montane Moist Forest-Wet Forest Transition. Voucher specimens of the species investigated (Bawa 3001 and 3002) have been deposited in the herbarium of the California Academy of Sciences (CAS), San Francisco. FLOWER MORPHOLOGY AND

(1) Crown architecture, growth and branch display were studied in two earlysuccessional (Anthocephalus cadamba and Duabanga sonneratioides) and two latesuccessional (Artocarpus chaplasha and Dillenia pentagyna) tree species of subtropical humid forest in north-eastern India. While the early-successional species conform morphologically to Massart's model (Duabanga sonneratioides) or Roux's model (Anthocephalus cadamba), the late-successional species conform to Scarrone's model (Dillenia pentagyna) or Rauh's model (A rtocarpus chaplasha) of tree architecture. (2) While rhythmic extension growth of the leader axis has been identified on the basis of differences in leaf morphology and branch organization in the architectural models, this does not always agree with detailed growth analysis as, for example, in Anthocephalus cadamba and Duabanga sonneratioides. (3) The extension and radial growth rates of early-successional species were very rapid compared with late-successional species. (4) Faster growth over a longer annual-growth period results in the sparse branch arrangement in early-successional species which facilitates greater leaf exposure. (5) The slower growth rate over a shorter growth period results in densely packed canopies with mutual shading of leaves of late-successional species. (6) In the early-successional species the production and the contribution of first order branches to the total branch system was much higher than in the late-successional species, which had plasticity in the orientation and overall display of their branches in relation to irradiance.

Indian Woods Their Identification, Properties and Uses. By Dr. K. A. Chowdhury and S. S. Ghosh. With the assistance of K. Ramesh Rao and S. K. Purkayastha. Vol. 1: Dilleniaceae to Elaeocarpaceae. Pp. liii + 304 + 30 plates. (Delhi: Manager of Publications, 1958.) Rs. 25.50 n.p.; 39s.

THE vascular anatomy of the flower in many families of plants has been studied in recent years ; but the family Dilleniaceae has escaped attention. For this reason the floral anatomy of Dillenia indica Linn., Wormia triquetra Rottb. and Wormia Burbidgei Hook, has been investigated. The study has brought to light a number of interesting points, but the vascular supply of the pedicel and the ovule particularly has been found to be very unusual.

Some of the important vegetative characters of amentiferous families described in research papers concerned with interfamilial relationships and published since 1947–1948 are briefly summarized. Important conclusions by the writers are also reviewed. Thus, Bataceae are considered derivatives of the Centrospermae ; Betulaceae, Casuarinaceae, and Ulmaceae are hamamelidaceous derivatives; Garryaceae and Cornaceae are closely related; and Julianiaceae and Anacardiaceae are plausible relatives. A more extensive tabulation of vegetative characters of essentially all amentiferous and ranalean families and Dilleniaceae is also presented, and the data are utilized to compare the percentages of advanced and primitive characters in these same taxa. The logic for considering trends whose evolutionary directions were initiated previous or incidental to angiospermous origin as more valid than other evolutionary trends is offered. The following principal conclusions are based upon the analysis of the tabulation: (1) the Amentiferae have sufficient advanced vegetative characters to preclude consideration of them as earliest angiosperms or their direct derivatives unless a large number of primitive features of other sorts offers strong counter evidence; (2) they also have sufficient primitive characters to discount the concept that they are highly evolved; (3) most Amentiferae clearly possess many more advanced vegetative characters than do most Magnoliales, Laurales, Trochodendrales, or Dilleniaceae ; and (4) relationships of several Amentiferae to various, unrelated angiospermous families have been demonstrated.