Favio González

Phylogenetic Relationships in Aristolochiaceae

Abstract A phylogenetic analysis was conducted to examine the monophyly and relationships of the four broadly defined genera of Aristolochiaceae. Seventy-two morphological characters were coded from representatives of these genera and from a broad selection of potential outgroups. The data support monophyly of the Aristolochiaceae and monophyly of the broadly defined genera Aristolochia, Thottea, and Asarum. The genera are grouped into two clades within the family, Thottea + Aristolochia and Asarum + Saruma. Based on the results of these analyses, Asaroideae, which have been circumscribed by some authors to consist of Saruma, Asarum, and Thottea, are paraphyletic, and should be emended to exclude Thottea.

SYSTEMATICS OF PIPEVINES: COMBINING MORPHOLOGICAL AND FAST-EVOLVING MOLECULAR CHARACTERS TO INVESTIGATE THE RELATIONSHIPS WITHIN SUBFAMILY ARISTOLOCHIOIDEAE (ARISTOLOCHIACEAE)

A combined phylogenetic analysis of the Aristolochioideae was conducted based on 72 morphological characters and molecular data sets (matK gene, trnK intron, trnL intron, trnL‐trnF spacer). The analysis sampled 33 species as the ingroup, including two species of Thottea, 30 species of Aristolochia, and the monotypic genus Euglypha, which represent all the infrageneric taxa formally described; Saruma henryi and Asarum caudatum were used as the outgroup. The results corroborate a sister‐group relationship between Thottea and Aristolochia and the paraphyly of Aristolochia with respect to Euglypha, which consequently should be included in Aristolochia. Two of the three subgenera within Aristolochia (Isotrema and Pararistolochia) are shown to be monophyletic, whereas the signal obtained from the different data sets about the relationships within subgenus Aristolochia is low and conflicting, resulting in collapsed or unsupported branches. The relationship between the New World and the Old World species of subgenus Aristolochia is conflictive because morphological data support these two groups as monophyletic, whereas molecular data show the monophyletic Old World species of Aristolochia nested within the New World species. A sister‐group relationship is proposed between Aristolochia lindneri and pentandrous species, which suggests that a group of five species from central and southern South America (including A. lindneri) could be monophyletic and sister to Aristolochia subsect. Pentandrae, a monophyletic taxon consisting of ca. 35 species from the southern United States, Mesoamerica, and the West Indies.

Perianth development and systematics of Aristolochia.

Summary A comparative study of the development and morphology of the perianth in 42 species of Aristolochia is presented. These species represent all the subgenera, sections, and subsections formally proposed within this genus. Additional observations on the perianth of Asarum, Saruma and Thottea are also included because perianth morphology has been crucial for the classification of the Aristolochiaceae. The results support the interpretation of the perianth of Aristolochia , Euglypha and Holostylis as a trimerous calyx. Five main types of perianth development were found in Aristolochia which differ in the degree of fusion between the perianth lobes, the direction of floral curvature, and the symmetry of the perianth limb. The interpretation of the perianth of Aristolochia as a calyx is supported in terms of position, morphology, development, and comparison to related taxa.

Flower and fruit characters in the early-divergent lamiid family Metteniusaceae, with particular reference to the evolution of pseudomonomery

Evaluating the morphological relationships of angiosperm families that still remain unplaced in the current systems of classification is challenging because it requires comparative data across a broad phylogenetic range. The small neotropical family Metteniusaceae was recently placed within the lamiids, as sister to either the enigmatic Oncothecaceae or the clade (Boraginaceae + Gentianales + Lamiales + Solanales + Vahliaceae). We examined the development of two of the primary diagnostic traits of Metteniusaceae, the moniliform anthers and the unilocular gynoecium. The gynoecium is 5-carpellate, and contains two ovules with a massive, vascularized integument. Late sympetaly and unitegmic ovules support placement of Metteniusaceae in the lamiids. The 5-carpellate gynoecium is consistent with a sister-group relationship between Metteniusaceae and Oncothecaceae. The gynoecium of Metteniusaceae is unusual in that it is monosymmetric throughout ontogeny, which indicates pseudomonomery; the five carpel initials are congenitally fused by their margins and form a single locule; the two ovules develop from the two smallest and most poorly developed lateral carpels. Comparisons with other pseudomonomerous taxa allow us to propose division of the complex processes leading to pseudomonomery into eight characters, including carpel number and fusion, gynoecial symmetry, timing of carpel reduction, and number and position of nonfertile carpels.

Structure and development of the ovule and seed in Aristolochiaceae, with particular reference to Saruma

Abstract.All members of Aristolochiaceae have anatropous, bitegmic, crassinucellate ovules, which are endostomic except in Saruma and Asarum arifolium where ovules are amphistomic. The outer integument is two cell-layered and the inner integument is three cell-layered. The chalazal megaspore is the functional one. All these conditions appear to be plesiomorphic for the order Piperales, which consists of five families, Aristolochiaceae, Hydnoraceae, Lactoridaceae, Piperaceae and Saururaceae. The embryo sac in Aristolochiaceae is eight-nucleate and corresponds to the Polygonum type; a hypostase is frequently present in this family. The seed coat of Aristolochia s.l., Asarum, Saruma and some Thottea species consists primarily of a two cell-layered testa, and a three cell-layered tegmen. In some species the cells of the outer epidermis become radially elongated, forming reticulate wall thickenings. Cells of the inner layer of the testa have crystals and thickened inner walls. The three layers of the tegmen are tangentially elongated, and become cross fibres at maturity, as fibres of the outer and inner layers are parallel to the seed axis, whereas those of the middle layer are perpendicular to it. This type of seed coat anatomy is synapomorphic for Aristolochiaceae. In addition, the gross morphology of the seed and elaiosome histology are remarkably similar in Asarum and Saruma, thus supporting a sister-group relationship between them. Embryological and seed characters do not supply any synapomorphy that support a close relationship between Aristolochiaceae, Hydnoraceae and Lactoridaceae. Instead, some seed features such as the absence of seed appendages and the collapsed cells of endotesta may indicate a close relationship of Lactoris with Piperaceae plus Saururaceae, although this is the subject of further analysis.

The questionable affinities of Lactoris: Evidence from branching pattern, inflorescence morphology, and stipule development

The phylogenetically ambivalent monotypic genus Lactoris presents sympodial (determinate) branching, as a terminal flower is present on each main branch. The synflorescence is thyrsoid. Partial inflorescences are rhipidia with up to three flowers. The ochrealike stipule is formed by the fusion of two lateral stipules, which forms an adaxial ligule-like structure and a two-flanked leaf sheath that encircles the parental axis. The leaf sheath elongates with the growth of the preceding internode. Although sympodial growth and a sheathing leaf base are present in all Piperales (Aristolochiaceae, Lactoridaceae, Piperaceae, and Saururaceae), the presence of stipules is confined to Lactoris, Saururaceae, and some Piperaceae. These characters are consistent with the placement of Lactoris within Piperales, although its phylogenetic position within the order remains equivocal, except for the possible sister group relationship suggested by the presence of cymose inflorescences in both Lactoris and Aristolochiaceae.

FLORAL MORPHOLOGY AND DEVELOPMENT IN ARAGOA (PLANTAGINACEAE) AND RELATED MEMBERS OF THE ORDER LAMIALES

Inflorescence and floral morphology and development were investigated in Aragoa (Plantaginaceae) and related genera. Each inflorescence of Aragoa is a reduced, axillary raceme, on which the actinomorphic floral apices generally arise successively. The inflorescences of Aragoa and Plantago are polytelic and lateral. The five sepals emerge from the abaxial to the adaxial side of the floral apex, but at maturity, the calyx is actinomorphic. The four stamens arise simultaneously and before emergence of the petals. The four petals emerge unidirectionally united, but the corolla becomes actinomorphic. Aestivation is cochlear ascendent. The two united carpels initiate simultaneously. The abaxial‐adaxial inception of the calyx and corolla during early floral development in genera such as Aragoa, Digitalis, Plantago, and Veronica may indicate that the zygomorphic condition is ancestral in those genera. The tetramerous corolla, which is actinomorphic during middle and late development, and the presence of four stamens are possible synapomophies of the clade ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Limited mitogenomic degradation in response to a parasitic lifestyle in Orobanchaceae

Aragoa+Plantago