Márcio Lacerda Lopes Martins

What's New in Manihot (Euphorbiaceae)?

Abstract We describe two new species of Manihot (Euphorbiaceae), and present an updated description of M. pusilla and a synonymization of M. stipularis to M. pusilla. Manihot bellidifolia, and M. longiracemosa found in campos rupestres and cerrado vegetations, reinforce the preference of this genus for habitats with restricted water availability. The two species described here are threatened with extinction, in the category of vulnerable. Manihot stipularis is considered a synonym of M. pusilla due to the wide morphological variation of its stipules, the principal character used to distinguish these species.

Levantamento florístico de um brejo-herbáceo localizado na restinga de Morada do Sol, município de Vila Velha, Espírito Santo, Brasil

This paper presents the floristic composition of a sedge- swamp located in Morada do Sol, Vila Velha, Espirito Santo. Samples were collected through random walks, these being fertile branches of angiosperms and ferns. We recorded 125 species in 56 families. The Asteraceae family showed highest species richness with 13 species, followed by Cyperaceae with 12, Fabaceae 9, Rubiaceae and Poaceae with 8 and 7 species respectively. Melanopsidium nigrum Colla is on the official list of endangered species and 29 other species are first citations for the salt marsh vegetation of Espirito Santo. The presence of 28 invasive species is due to changes caused by the decrease in the flooded area by intentional landfill and burning at short intervals, which promote floristic and physiognomic changes in the ecosystem.

Manihot cezarii (Euphorbiaceae), a New Species from Central-Western Brazil

Abstract.  Manihot cezarii M. Martins (Euphorbiaceae) is described and illustrated from the states of Goiás and Mato Grosso, Brazil. This species has flat, greenish blue leaves and pendent inflorescences with foliaceous bracts, characteristics that distinguish it from M. alutacea D. J. Rogers & Appan. The conservation status of the new species is assessed as Endangered (EN), according to IUCN Red List criteria.

Obtenção de híbridos de cultivares e de subespécies silvestres de mandioca

The objective of this work was to evaluate the crossability between cassava (Manihot esculenta subsp. esculenta) cultivars and the subspecies M. esculenta subsp. flabellifolia and M. esculenta subsp. peruviana. Plants from the BRS Jari, BRS Formosa, BRS Verdinha, and BGM 2050 (Equador 72) cultivars were crossed with the two subspecies. During flowering, at pre-anthesis, pistillate flowers were covered with a nylon bag and staminate flowers on the same inflorescence were emasculated. The staminate flowers were collected and placed in flasks previously labeled and sterilized with alcohol; some fresh flowers were stored at room temperature due to asynchronous flowering. The crosses were made between 10 a.m. and 2 p.m. After pollination, the flowers were covered again. Evaluations were made from the moment of pollination to the dehiscence of the fruit. Of the total flowers pollinated, 38% were fertilized, and 504 developed fruits and 816 produced seeds were observed. As a male parent, M. esculenta subsp. flabellifolia is more efficient in crosses with M. esculenta subsp. esculenta and may be recommend for controlled crosses. The crosses between the cassava cultivars and M. esculenta subsp. flabellifolia and M. esculenta subsp. peruviana produce viable seeds.

Distinctive New Species of Manihot (Euphorbiaceae) from Brazil

Abstract. Three species of Manihot Mill. from Brazil, M. decurrens M. Mend. & M. Martins, M. pandurata M. Mend. & M. Martins, and M. sagittata M. Mend. & M. Martins, are described and illustrated as new based on qualitative morphological characters observed from herbarium material, complemented with in situ observations of M. sagittata. Morphological characteristics of the new taxa, as well as morphological comparisons with closely related species and comments on natural distribution and ecological aspects, are provided.