PSYCHOTRIA FARAMEOIDES BREM. N. SPEC. (RUBIACEAE)

Absence of alkaloids in Psychotria carthagenensis Jacq. (Rubiaceae).

Psychotria viridis and P. carthagenensis are often discussed in relation to the hallucinogenic beverage Ayahuasca, used for religious, medicinal and social purposes. The significance of including Psychotria species in this beverage has been understood on the basis of substantial amounts of tryptamine alkaloids detected on leaves of both P. viridis and P. carthagenensis. Nevertheless, there is a...

Cytotoxic activity of polyindoline alkaloids of Psychotria forsteriana (Rubiaceae) (1).

Raphide crystal cell development in leaves of Psychotria punctata (Rubiaceae).

The distribution and development of raphide cry8tal cells in nodulated leaves of Psychotria punctata were studied by light and electron microscopy. Crystal cells in the leaf are oriented in various ways depending on whether they occur in the spongy or palisade parenchyma. Crystals are never found within the bacterial nodules and are not concentrated around them. Developing leaf crystal cells be...

Storage in cerrado soil and germination of Psychotria vellosiana (Rubiaceae) seeds.

The regeneration of plant communities from seed depends, to a large extent, on the capacity of the seed remaining viable in the soil. The viability and germination of artificially buried Psychotria vellosiana seeds in cerrado soil were studied, with the purpose of discovering some physio-ecological aspects of dispersed seeds and evaluating their potential to constitute a soil seed bank. Seed sa...

Reproductive success and genetic diversity of Psychotria hastisepala (Rubiaceae), in fragmented Atlantic forest, Southeastearn Brazil.

The impacts of forest fragmentation on both reproductive biology and genetic diversity of native plant species is hardly understood, despite some studies have analyzed this current worldwide problem. Since this constitutes one of the main threats to seasonal semi-deciduous forests in Southeastern Brazil, we investigated the reproductive success and the genetic diversity of a distylous, understo...