Morphological analysis of vessel elements for systematic study of three Zingiberaceae tribes.

Zingiberaceae containing over 1,000 species that are divided into four subfamilies and six tribes. In recent decades, there has been an increase in the number of studies about vessel elements in families of monocotyledon. However, there are still few studies of Zingiberaceae tribes. This study aims to establish systematic significance of studying vessel elements in two subfamilies and three tribes of Zingiberaceae. The vegetative organs of 33 species processed were analysed by light and scanning electron microscopy and Principal Component Analysis was used to elucidate genera boundaries. Characteristics of vessel elements, such as the type of perforation plate, the number of bars and type of parietal thickening, are proved to be important for establishing the relationship among taxa. Scalariform perforation plate and the scalariform parietal thickening are frequent in Zingiberaceae and may be a plesiomorphic condition for this taxon. In the Principal Component Analysis, the most significant characters of the vessel elements were: simple perforation plates and partially pitted parietal thickening, found only in Alpinieae tribe, and 40 or more bars composing the plate in Elettariopsis curtisii, Renealmia chrysotricha, Zingiber spectabile, Z. officinale, Curcuma and Globba species. Vessel elements characters of 18 species of Alpinieae, Zingibereae and Globbeae were first described in this work.

Topological Phenotypes Constitute a New Dimension in the Phenotypic Space of Leaf Venation Networks.

The leaves of angiosperms contain highly complex venation networks consisting of recursively nested, hierarchically organized loops. We describe a new phenotypic trait of reticulate vascular networks based on the topology of the nested loops. This phenotypic trait encodes information orthogonal to widely used geometric phenotypic traits, and thus constitutes a new dimension in the leaf venation phenotypic space. We apply our metric to a database of 186 leaves and leaflets representing 137 species, predominantly from the Burseraceae family, revealing diverse topological network traits even within this single family. We show that topological information significantly improves identification of leaves from fragments by calculating a "leaf venation fingerprint" from topology and geometry. Further, we present a phenomenological model suggesting that the topological traits can be explained by noise effects unique to specimen during development of each leaf which leave their imprint on the final network. This work opens the path to new quantitative identification techniques for leaves which go beyond simple geometric traits such as vein density and is directly applicable to other planar or sub-planar networks such as blood vessels in the brain.

Plant Identification Based on Leaf Midrib Cross-Section Images Using Fractal Descriptors.

The correct identification of plants is a common necessity not only to researchers but also to the lay public. Recently, computational methods have been employed to facilitate this task, however, there are few studies front of the wide diversity of plants occurring in the world. This study proposes to analyse images obtained from cross-sections of leaf midrib using fractal descriptors. These descriptors are obtained from the fractal dimension of the object computed at a range of scales. In this way, they provide rich information regarding the spatial distribution of the analysed structure and, as a consequence, they measure the multiscale morphology of the object of interest. In Biology, such morphology is of great importance because it is related to evolutionary aspects and is successfully employed to characterize and discriminate among different biological structures. Here, the fractal descriptors are used to identify the species of plants based on the image of their leaves. A large number of samples are examined, being 606 leaf samples of 50 species from Brazilian flora. The results are compared to other imaging methods in the literature and demonstrate that fractal descriptors are precise and reliable in the taxonomic process of plant species identification.

[Structure, ontogeny and vascularization of the flowers and inflorescences of Drimys granadensis (Winteraceae)]. / Estructura, ontogenia y vascularización de las flores e inflorescencias de Drimys granadensis (Winteraceae).

Structure, ontogeny and vascularization of the flowers and inflorescences of Drimys granadensis (Winteraceae). Drimys granadensis is a widespread species in montane forests of South and Central America. In this research, the structure, ontogeny, phyllotaxis and vascularization of the flowers and inflorescences of this species was studied in a population from the Eastern hills of Sabana de Bogota, Colombia. The methods used applied both optical microscopy, with astra blue-fuchsin staining, and scanning electron microscopy, using critical point dryed and gold-paladium metallized samples. Besides, results were compared with those of Drimys winteri, a widely studied species distributed in Chile and Argentina. Additionally, we studied the detail of the floral anatomy to determine the bracteal or calicine identity of the caliptra. I confirmed the proliferative status of the monothelic inflorescence, discarding alternative explanations of the terminal flower identity. I found that uniflorescences have an acropetal development until the terminal meristem becomes the terminal flower, then this flower develops rapidly resulting in a determined uniflorescence. I found pseudosyphonosthelic vascularization in peduncles and pedicels. Besides, I discovered some evidence in the vascular and anatomical structures, to consider the caliptra as the fusion product of various structures and therefore of calicine origin. The caliptra showed a whorled phyllotaxis, but the petals, stamens and carpels presented a spiral condition; phyllotaxis change was explained by the long time lapse between the initiation of the calyx and the corolla. I found great similarities among the inflorescences of D. granadensis and D. winteri; they were different in the proliferation start time, and in the frequent presence of nomophylls in D. granadensis, in contrast to the presence of reduced bracts and bracteoles in D. winteri inflorescences.

Estructura, ontogenia y vascularización de las flores e inflorescencias de Drimys granadensis (Winteraceae) / Structure, ontogeny and vascularization of the flowers and inflorescences of Drimys granadensis (Winteraceae)

Drimys granadensis is a widespread species in montane forests of South and Central America. In this research, the structure, ontogeny, phyllotaxis and vascularization of the flowers and inflorescences of this species was studied in a population from the Eastern hills of Sabana de Bogota, Colombia. The methods used applied both optical microscopy, with astra blue-fuchsin staining, and scanning electron microscopy, using critical point dryed and gold-paladium metallized samples. Besides, results were compared with those of Drimys winteri, a widely studied species distributed in Chile and Argentina. Additionally, we studied the detail of the floral anatomy to determine the bracteal or calicine identity of the caliptra. I confirmed the proliferative status of the monothelic inflorescence, discarding alternative explanations of the terminal flower identity. I found that uniflorescences have an acropetal development until the terminal meristem becomes the terminal flower, then this flower develops rapidly resulting in a determined uniflorescence. I found pseudosyphonosthelic vascularization in peduncles and pedicels. Besides, I discovered some evidence in the vascular and anatomical structures, to consider the caliptra as the fusion product of various structures and therefore of calicine origin. The caliptra showed a whorled phyllotaxis, but the petals, stamens and carpels presented a spiral condition; phyllotaxis change was explained by the long time lapse between the initiation of the calyx and the corolla. I found great similarities among the inflorescences of D. granadensis and D. winteri; they were different in the proliferation start time, and in the frequent presence of nomophylls in D. granadensis, in contrast to the presence of reduced bracts and bracteoles in D. winteri inflorescences.

Drimys granadensis es una especie de amplia distribución en los bosques montanos de Sur y Centro América. En esta investigación se estudiaron, mediante microscopía óptica y electrónica de barrido, la estructura, ontogenia, filotaxis y vascularización de sus flores e inflorescencias, y fueron comparadas con las de Drimys winteri, especie distribuida en Chile y Argentina. Adicionalmente, se buscó evidencia para determinar la identidad bracteal o calicina de la caliptra de sus flores. Se confirmó la condición monotélica proliferante de la inflorescencia, descartando explicaciones alternativas de identidad de la flor terminal. Las uniflorescencias presentan un desarrollo acrópeto, hasta que el meristemo terminal se transforma en flor terminal, entonces esta flor se desarrolla rápidamente dando lugar a una uniflorescencia determinada. La vascularización es pseudosifonostélica para pedúnculos y pedicelos. Se encontró evidencia en la vascularización y estructura anatómica para considerar la caliptra como el producto de fusión de varias estructuras y, por tanto, de origen calicino. La caliptra presentó una filotaxis verticilada, pero los pétalos, estambres y carpelos presentaron una filotaxis espiralada; el cambio se explicó por el tiempo prolongado entre la iniciación de cáliz y corola. Las inflorescencias de D. granadensis y D. winteri son muy similares; siendo diferente el tiempo de inicio de la proliferación y la frecuente presencia de nomófilos en las inflorescencias de D. granadensis, en contraste con la presencia de brácteas y bracteolas reducidas en D. winteri.

The phylogenetic significance of the carpophore in Apiaceae.

BACKGROUND AND AIMS: Fruit structural characters have traditionally been important in the taxonomy of the family Apiaceae. Previous investigations using a limited number of taxa have shown that the carpophore may be especially useful in helping to circumscribe subfamily Azorelloideae. The present study examines, for the first time, carpophore structure in 92 species from 43 genera, representing all subfamilies of Apiaceae, and including all genera assigned to subfamily Azorelloideae. Phylogenetic interpretations are made for the first time, using all available information, and a standard terminology is proposed to describe the various character states found in carpophores. METHODS: Carpophore structure was studied in detail using light microscopy. KEY RESULTS: Carpophores, when present, may be categorized into two main groups (B and C) based mainly on the arrangement of the vascular bundles in transverse section, and further divided into six sub-types according to the length of the carpophore (short in B1 and C1) and whether they are entire (B1-B3 and C1) or bifurcate (B4 and C2). Free carpophores are absent in subfamily Mackinlayoideae, and in tribes Lichtensteinieae and Phlyctidocarpeae, which have two opposite vascular bundles (Group A). Entire carpophores with one or two vascular bundles, or bifurcate carpophores with lateral vascular bundles (arranged side by side within the commissural plane), are the main types characterizing Azorelloideae. The short, hygroscopic carpophores found in Choritaenia are unique in Apiaceae and provide additional evidence for the exclusion of this genus from Azorelloideae. Carpophore type C2 is typical for most Apioideae sensu lato (exceptions are, for example, Arctopus and Alepidea, which have type B2). CONCLUSIONS: A single carpophore and ventral vascular bundles not forming free carpophores are proposed to be the ancestral conditions in Apiaceae, while bifurcate carpophores with opposite vascular bundles are the derived state, present in most Apioideae. Secondary reductions seem to have occurred in several unrelated lineages in all major groups, e.g. many Azorelloideae, several protoapioids (including nearly all members of the tribe Saniculeae) and 29 euapioid genera (e.g. some Oenantheae).