A Mojave Desert shrub community was experimentally burned to understand changes in seed bank of desert annual plant species in response to wildfire. Seed mortality ranged from 55 to 80%, and fire caused significant losses of native and alien annual seeds. Schismus arabicus, Schismus barbatus, Bromus madritensis, Bromus tectorum, Erodium cicutarium and Plantago spp. made up >95% of the seed bank...

Overall phylogenetic relationships within the genus Pelargonium (Geraniaceae) were inferred based on DNA sequences from mitochondrial(mt)-encoded nad1 b/c exons and from chloroplast(cp)-encoded trnL (UAA) 59 exon–trnF (GAA) exon regions using two species of Geranium and Sarcocaulon vanderetiae as outgroups. The group II intron between nad1 exons b and c was found to be absent from the Pelargoni...

Abstract Twisted structures are ubiquitous in plants and animals. Cellulose chitin natural polymers that form the structural skeleton of various twisted systems observed across different length scales, ranging from molecular to nano, micro, macro scale. In addition, cellulose helicoidal found be responsible for coloration, enhanced mechanical properties, motion. This review first addresses chit...

Influence of growth temperature on the capacity of the mitochondrial alternative pathway of electron transport was investigated using etiolated corn (Zea mays L.) seedlings. These seedlings were grown to comparable size in either a warm (30 degrees C) or a cold (13 degrees C) temperature regime, and then their respiration rates were measured as O(2) uptake at 25 degrees C. The capacity of the a...

Erodium paularense is a threatened plant species that is subject to seed predation by the granivorous ant Messor capitatus. In this paper we assessed the intensity and pattern of ant seed predation and looked for possible adaptive strategies at the seed and plant levels to cope with this predation. Seed predation was estimated in 1997 and 1998 at the population level by comparing total seed pro...

Natural product herbicides for vegetation control are being considered as alternatives to synthetic herbicides by many public agencies. Studies were conducted along roadsides at the Hopland Research and Extension Center (HREC) in 2001 and 2002 and on California State Route 29 (SR29) in 2002 to evaluate acetic acid, pine oil, and plant essentials compared with glyphosate for control of herbaceou...

Phytochemical investigation of the cytotoxic fractions of fresh bulbs of Pancratium maritimum L. led to the isolation and structure identification of two new compounds, pancricin (1) and pancrichromone (4), together with four known compounds, including 2,4-dihydroxy-6-methoxy-3-methyl acetophenone (2), 5-formylfurfuryl acetate (3), 7-beta-D-glucosyloxy-5-hydroxy-2-methylchromone (5), and ethyl-...