Flow makes vein L eaf veins, just like roots and shoots, use fl ows of the plant hormone auxin to drive their patterning, say Enrico Scarpella (University of Alberta, Canada), Thomas Berleth (University of Toronto, Canada), and colleagues. Models for leaf vein patterning have been based on either auxin fl ows or reaction–diffusion systems. The fl ow models had a hard time explaining how loops w...

Hydraulic architecture parameters, water relation parameters and wood anatomy were studied in roots and shoots of the flood-tolerant tree Annona glabra L. on Barro Colorado Island, Panama. Hydraulic conductivity, leaf specific conductivity, and Huber value were similar to the corresponding values for tree species living in non-flooded habitats. The vulnerability of stems to loss of hydraulic co...

Farfugium japonicum is used in traditional medicine and as an edible herb in China and Korea. In July 2013, leaf spots were observed in F. japonicum seedlings at Ulleung Island, Gyeongsangbuk Province, Korea. Early symptoms on the leaf adaxial surface included roughly circular yellow spots that later developed brown, necrotic centers. The aecia were hypophyllous, cupulate, yellowish, 180~430 µm...

We consider computational modeling of biological systems that consist of discrete components arranged into linear structures. As time advances, these components may process information, communicate and divide. We show that: (1) the topological notion of cell complexes provides a useful framework for simulating information processing and flow between components; (2) an index-free notation exploi...

The difference in size, shape, and chemical cues of leaves and flowers display the underlying genetic makeup and their interactions with the environment. The need to understand the molecular signatures of these fragile plant surfaces is illustrated with a model plant, Madagascar periwinkle (Catharanthus roseus (L.) G. Don). Flat, thin layer chromatographic imprints of leaves/petals were imaged ...

Lithocarpus dahuoaiensis Ngoc & L. V. Dung, a new species from the Central highland of Vietnam, is described and illustrated. The new species is morphologically similar to Lithocarpus macphailii (M. R. Hend.) Barnett or Lithocarpus encleisocarpus (Korth.) A. Camus in having completely entire leaf margin, solitary cupule, long stalks of fruits, deeply cup-shaped or turbinate cupules, with a numb...

Due to both anthropogenic and natural causes, the number of Horsfieldia hainanensis has been decreasing each year in Tongza Branch nursery (109.534 525°E, 18.763 516°N) Hainan Academy Forestry, China. Consequently, protection H. is urgent, as that most rare tree species. To develop a more comprehensive understanding growth environment, we took 3-year-old saplings research object. We controlled ...

Typhoon No. 13 in 2006 (Typhoon 0613) passed through Yamaguchi Prefecture, Japan on Sep. 17, 2006. After being hit by it, many landscape trees, especially ginkgo in Yamaguchi City, showed symptoms of necrosis on the leaf tip and margin, and even the entire leaf. It clearly divided the crowns of some ginkgo trees into the green part and the non-green part. In order to quantitatively study this p...

Tomato chlorosis virus (ToCV), and Tomato infectious chlorosis virus (TICV), family Closteroviridae, genus Crinivirus, cause interveinal chlorosis, leaf brittleness, and limited necrotic flecking or bronzing on tomato leaves. Both viruses cause a decline in plant vigor and reduce fruit yield, and are emerging as serious production problems for field and greenhouse tomato growers in many parts o...

Herbarium specimens are a vital resource in botanical taxonomy. Many herbaria are undertaking large-scale digitization projects to improve access and to preserve delicate specimens, and in doing so are creating large sets of images. Leaf characters are important for describing taxa and distinguishing between them and they can be measured from herbarium specimens. Here, we demonstrate that herba...