Generosa Teixeira

Taxonomic re-evaluation of the Azolla genus in Portugal

ABSTRACT The Portuguese and the European Flora refer to the presence of two or three Azolla species in Portugal: A. filiculoides Lam., A. caroliniana Willd. and/or Azolla mexicana Presl., the latter included in the last edition of Flora Europaea. In the present work, the taxonomy of Azolla species is reviewed using the two most important characters that can distinguish between these two/three species: papillae in the dorsal leaf lobe and perine architecture of the megaspore apparatus. Other characteristics, such as the hyaline border cells of the dorsal leaf lobes and the number of glochidia septa in microsporangium massulae, are also used. All the Azolla specimens, collected from several locations in Portugal, were identified as Azolla filiculoides Lam. This identification disagrees with previous published reports on Azolla taxonomy in Portugal as well as with herbarium identification.

Antioxidant and Antimycotic Activities of Two Native Lavandula Species from Portugal

The antioxidant and antimycotic activities of the essential oils and extracts of two native Portuguese Lavandula species, L. stoechas subsp. luisieri and L. pedunculata, were evaluated by in vitro assays. The total phenolics and flavonoids content were also determined. The antioxidant potential was assessed through DPPH radical scavenging, inhibition of lipid peroxidation (ILP), and DNA protection assays. All samples displayed a high DPPH scavenging activity, some of them showing concentration dependence. The majority of the samples were also able to inhibit lipid peroxidation. A strong correlation was observed between the results of DPPH and ILP assays and the flavonoids content of the samples. In the DNA protection assay, all the extracts were able to preserve DNA integrity. The antimycotic activity was performed against twelve fungi belonging to Basidiomycota and Ascomycota Divisions. L. stoechas subsp. luisieri exhibited the broadest activity spectra. L. pedunculata extracts were active against five fungi. Cryptococcus neoformans was the most sensitive, being inhibited by all the extracts. Our results led to the conclusion that L. stoechas subsp. luisieri and L. pedunculata can be useful as new sources of natural antioxidants and antimycotic agents, providing a possible valorization of the existing biodiversity and resources of Portuguese flora.

Preliminary data on microcharacters and chromosome number in Tornabenea species (Apiaceae) from Cape Verde islands

Abstract Tornabenea is a small Apiaceae genus that is endemic to the Cape Verde Islands. Its species differentiation is based just on a few macromorphological characters: leaf shape, number and shape of umbel bracts and mericarp ribs. These characters vary within each species and show high plasticity. Thus, in recent taxonomic data of the genus, there are different viewpoints as to the number of species. Here, in order to improve the taxonomy of the genus, microcharacters of the vegetative and reproductive structures of three taxa—T. insularis, T. annua and T. tenuissima—have been examined. The shape and arrangement of hairs on the surface of the mericarps, and the presence and structure of starch grains are the only different microcharacters noted in T. insularis and T. annua. Chromosome number of the latter two species is 2n = 18. Our preliminary results disagree with the existing classifications of the genus Tornabenea. In fact, they do not lead to a clear separation between T. insularis and T. annua. By contrast, it is easy to distinguish between these species and T. tenuissima, which possesses more peculiar microcharacters.

Winged stems in Pterospartum tridentatum: morphoanatomical study

Abstract Some members of the subtribe Genistinae show winged stems instead of leaves. Using techniques of light and scanning microscopy, the mor- phoanatomy and some microcharacters of the winged stem of Pterospartum. tridentatum are described and compared with those of other close taxa, also inserted in the Genistinae and with whom P. tridentatum is mistaken: Chamaespartium tridentatum (L.) Gibbs, C. sagittale (L.) Gibbs and G. florida L. P. tridentatum winged stem presents a peculiar anatomy, with characteristics of a dicot stem and leaf. The central vein is organized as a secondary stem and vascular tissues are surrounded by a ring of mechanical elements. Some epidermal microcharacters, such as the predominant type of stornata and their way of insertion, are unique and are not found in the other Genistinae studied. These characters were not described in P. tridentatum and support its delimitation as a distinct and natural taxon.

C-glycosylflavones in the genus Azolla

ABSTRACT Two C-glycosylflavones were isolated from the root extracts of fresh material of Azolla filiculoides Lam. and A. pinnata subsp. africana (Desv.) R. M. K. Saunders & K. Fowler. They were also detected in herbarium material of A. caroliniana Willd. and A. nilotica Decne. ex Mett. Their structures were assigned to homoorientin (luteolin 6-C-glucosside) and saponarin (isovitexin 7-O-glucoside). Homoorientin and saponarin have not been previously reported in the genus Azolla. Our results indicate that roots and fronds present a different polyphenolic composition. Previous studies and our own results point to a certain chemical homogeneity in the genus Azolla, with regard to polyphenols.

Antidepressant Plant Species from the Portuguese-Speaking African Countries (PALOP)

The Portuguese-speaking African countries belong to the sub-Saharan region and are known by the acronym PALOP. As in other African countries, the traditional medicine is an important element in their cultural patrimony and the value of those ancestral practices is recognized.