Floral thermogenesis plays a crucial role in pollination biology, especially in plant-pollinator interactions. We have recently explored how thermogenesis is related to pollinator activity and odour release in Magnolia sprengeri. By analyzing flower temperatures, emission of volatiles, and insect visitation, we found that floral blends released during pistillate and staminate stages were simila...

BACKGROUND Flowers in Eriocaulaceae, a monocot family that is highly diversified in Brazil, are generally trimerous, but dimerous flowers occur in Paepalanthus and a few other genera. The floral merism in an evolutionary context, however, is unclear. Paepalanthus encompasses significant morphological variation leading to a still unresolved infrageneric classification. Ontogenetic comparative st...

HILE spinach (Spina& oleracea L.) is usually considered to be dioecious, W there is a continuous range of monoecious types as regards the proportion of pistillate to staminate flowers per plant. Sex determination in dioecious strains of spinach is controlled by a mechanism that acts as if it were a single factor pair; the pistillate plant is homozygous ( X X ) , and the staminate plant is heter...

BACKGROUND AND AIMS The reproductive biology of Syngonanthus mucugensis and S. curralensis (Eriocaulaceae) was studied in areas of 'campo rupestre' vegetation in the Chapada Diamantina, north-eastern Brazil. These species are herbaceous and the individuals have a grouped distribution. Their leaves are united in a rosette, and their inflorescence is monoecious, of the capitulum type. The stamina...

In gynodioecious plant species, females are expected to have more resources available for maturing seeds because pistillate flowers are smaller, do not produce pollen, and are thus less costly that perfect flowers. The potential female advantage arising from more abundant resources is, however, likely to vary depending on whether seed production is limited by resource or pollen availability. He...

A newly recovered twig with attached leaves and flowers from the Eocene Green River Formation of Utah provides the basis for recognizing a new, extinct genus of Salicaceae sensu lato (s.l.). Pseudosalix handleyi gen. et sp. nov. has alternate lanceolate leaves with pinnate, semicraspedodromous venation and a serrate margin with glandular teeth. The inflorescence is terminal on the twig and is u...

Syngonanthus weddellii var. gracilis Moldenke, (1973) was described very briefly based on a single collection. A careful analysis reveals that this variety has dimerous flowers, free petals of the pistillate flower and bifid stigmatic branches. It is therefore misplaced in Syngonanthus Ruhland (1900). We transfer it to Paepalanthus Mart. (1834) at the species level, as it is distinct from morph...

During the preparation of the taxonomic treatment of Manihot in the Midwest Region of Brazil, a new species was found. Manihot fallax M.J. Silva & L.S. Inocencio is described, illustrated and morphologically compared with similar simple-leaved species. The conservation status, geographic distribution (including map), ecology, phenology and notes about leaf anatomy of the new species are given. ...

Cyclanthura flower weevils (Coleoptera: Curculionidae: Derelomini) are identified for the first time as pollinators of multiple species of Anthurium (Araceae) in Costa Rica. The weevils are present on the inflorescences in small numbers during the pistillate and staminate phase of anthesis, and consume plant tissues and pollen. The individuals of one species of Cyclanthura can visit several Ant...