(American Journal of Botany. 2003;90:0.)
© 2003 Botanical Society of America, Inc.
The Superformula: defining symmetry and shape
In an Invited Special Paper Johan Gielis makes a significant contribution to shape definition. He explores the applications of one simple geometrical equation, the Superformula, for modeling and understanding various shapes, demonstrating that many geometrical forms can be interpreted as modified circles or supercircular forms. He suggests that the formula elucidates a very basic geometry of nature. A large part of the utility of the superformula for plant biologists will be the ability to model the dazzling array of shapes and sizes found in the plant kingdom.
(see p. 333)
A manuscript by Lobova et al. describes the fruit morphology and dispersal ecology of Cecropia, a genus that plays a vital role in the regeneration of Neotropical forests. The paper draws on an extensive literature and original observations to illustrate the role that frugivorous bats play as dispersers of Cecropia (see cover). The authors demonstrate that the dispersal unit of Cecropia is the fruit and not the seed, clearing up a prevailing confusion. Their anatomical data combined with the ecological observations create an integrated, functional understanding of dispersal biology.
(see p. 388)
Samuel et al. have assembled a large set of newly obtained DNA sequence data, based on ITS, trnL intron, trnL-F spacer, and matK sequences, which has the potential to add to our understanding of divergence within both Hypochaeris, a genus represented by 13 species in Eurasia and northern Africa and approximately 60 species in South America, and more generally within Asteraceae. Their data corroborate Stebbins' 1971 hypothesis about the origin and radiation of Hypochaeris in South America. The authors characterize the radiation as extremely rapid and dramatic, with habitats colonized from sea level to the high Andes.
(see p. 496)
Few studies have focused on the effects of floral scents on pollinators. Here Miyake and Yafuso present excellent experimental data on the impact of floral scent on the reproductive biology of a plant. The authors conducted well controlled and designed experiments to determine the main scent-producing organs of Alocasia odora (Araceae), the role of scent in attracting pollinators, the correlation between attractiveness and size of the scent-producing organ, and finally the impact of floral scent on fruit set.
(see p. 370)
