No abstract

A phylogenetic analysis based on a combined dataset of three genes, nuclear 18S rDNA and plastid rbcL and atpB, indicates that the enigmatic Neotropical genus Metteniusa is a member of the lamiid (euasterid I) clade. The genus appears as an isolated taxon near, but perhaps not related exclusively to, Oncothecaceae, which supports its recognition as a separate family.

Premise of the Study Bilateral symmetry in core eudicot flowers is established by the differential expression of CYCLOIDEA (CYC), DICHOTOMA (DICH), and RADIALIS (RAD), which are restricted to the dorsal portion of the flower, and DIVARICATA (DIV), restricted to the ventral and lateral petals. Little is known regarding the evolution of these gene lineages in non‐core eudicots, and there are no reports on gene expression that can be used to assess whether the network predates the diversification of core eudicots. Methods Homologs of the RAD and DIV lineages were isolated from available genomes and transcriptomes, including those of three selected non‐core eudicot species, the magnoliid Aristolochia fimbriata and the monocots Cattleya trianae and Hypoxis decumbens. Phylogenetic analyses for each gene lineage were performed. RT‐PCR was used to evaluate the expression and putative contribution to floral symmetry in dissected floral organs of the selected species. Key Results RAD‐like genes have undergone at least two duplication events before eudicot diversification, three before monocots and at least four in Orchidaceae. DIV‐like genes also duplicated twice before eudicot diversification and underwent independent duplications specific to Orchidaceae. RAD‐like and DIV‐like genes have differential dorsiventral expression only in C. trianae, which contrasts with the homogeneous expression in the perianth of A. fimbriata. Conclusions Our results point to a common genetic regulatory network for floral symmetry in monocots and core eudicots, while alternative genetic mechanisms are likely driving the bilateral perianth symmetry in the early‐diverging angiosperm Aristolochia.

No abstract

No abstract

No abstract

Aristolochia longispathulata, a new species trom the "Mata Atlantica," is described and illustrated. The new species belongs to Aristolochia subser. Hexandrae F. Gonzalez. It is easily recog¬ nized by flowers that are slightly curved and have a long, spatulate, fimbriate limb, which is pale green on the inner surface. Aristolochia longispa¬ thulata is similar to A. arcuata and A. rumicifolia, from eastern and southeastern Brazil. Its floral mor¬ phology also resembles that of A. peltata, from the West Indies, and A. sessilifolia, from southern Bra¬ zil, Argentina, and Uruguay.Resumo. Neste trabalho uma nova especie de Ar¬ istolochiaceae da Mata Atlantica, Bahia, Brasil, A. longispathulata, e descrita e illustrada. Esta espe¬ cie pertence a Aristolochia subser. Hexandrae F. Gonzalez. E facilmente reconhecida por apresentar suas flores levemente curvadas, com o limbo longo, espatulado e fimbriado, alem de possuir a face adaxial atipicamente alvo-esverdeada. Aristolochia longispathulata e semelhante a A. arcuata e A. rumicifolia, especies da regiao oriental e sul-oriental do Brasil, embora a morfologia floral desta especie assemelha-se a de A. peltata, das Indias Ocidentais, ou da especie A. sessilifolia, do sul do Brasil, Argentina e Uruguai.

No abstract