C(4) photosynthesis is a series of anatomical and biochemical modifications to the typical C(3) pathway that increases the productivity of plants in warm, sunny, and dry conditions. Despite its complexity, it evolved more than 62 times independently in flowering plants. However, C(4) origins are absent from most plant lineages and clustered in others, suggesting that some characteristics increa...

Raveniopsis microphyllus K.Wurdack, sp. nov., a new species known only from a single peak in the Pakaraima Mtns. of Guyana, is described and illustrated. This white-flowered shrub adds to the many narrow-endemic Guiana Shield species in the genus, and is unique in bearing small, trifoliate, sclerophyllous leaves. Leaf anatomy and surface micromorphology of the new species were examined to docum...

Extrafloral glands in Passifloraceae species have aroused the interest of many researchers because of their wide morphological diversity. The present work analyzed the foliar glands on 34 species of Passiflora from samples containing glands in the petiole and foliar blade fixed in 50% solution of formaldehyde-ethanol-acetic acid and stored in a 70% ethanol solution. For anatomical analyses, par...