Late Campanian fossil of a legume fruit supports Mexico as a center of Fabaceae radiation.

Fabaceae is one of the most diverse angiosperm families and is distributed across the globe in a variety of environments. The earliest evidence of the family, previous to this work, was from Paleogene sediments where it was found to be diverse in many fossil assemblages around the world. Here, we describe a fossil legume fruit from the Olmos Formation (upper Campanian) in northern Mexico.

Vessel diameter is related to amount and spatial arrangement of axial parenchyma in woody angiosperms.

Parenchyma represents a critically important living tissue in the sapwood of the secondary xylem of woody angiosperms. Considering various interactions between parenchyma and water transporting vessels, we hypothesize a structure-function relationship between both cell types. Through a generalized additive mixed model approach based on 2,332 woody angiosperm species derived from the literature, we explored the relationship between the proportion and spatial distribution of ray and axial parenchyma and vessel size, while controlling for maximum plant height and a range of climatic factors.

Wood anatomy reveals high theoretical hydraulic conductivity and low resistance to vessel implosion in a Cretaceous fossil forest from northern Mexico.

The Olmos Formation (upper Campanian), with over 60 angiosperm leaf morphotypes, is Mexico's richest Cretaceous flora. Paleoclimate leaf physiognomy estimates indicate that the Olmos paleoforest grew under wet and warm conditions, similar to those present in modern tropical rainforests. Leaf surface area, tree size and climate reconstructions suggest that this was a highly productive system.

Shifts in climate foster exceptional opportunities for species radiation: the case of South african geraniums.

Climate change is often assumed to be a major driver of biodiversity loss. However, it can also set the stage for novel diversification in lineages with the evolutionary ability to colonize new environments. Here we tested if the extraordinary evolutionary success of the genus Pelargonium was related to the ability of its species to capitalize on the climate niche variation produced by the historical changes in southern Africa.

Wood anatomical correlates with theoretical conductivity and wood density across China: evolutionary evidence of the functional differentiation of axial and radial parenchyma.

Background And Aims: In recent years considerable effort has focused on linking wood anatomy and key ecological traits. Studies analysing large databases have described how these ecological traits vary as a function of wood anatomical traits related to conduction and support, but have not considered how these functions interact with cells involved in storage of water and carbohydrates (i.e.

Phylogenetic influences on leaf trait integration in Pelargonium (Geraniaceae): convergence, divergence, and historical adaptation to a rapidly changing climate.

Premise Of The Study: Trait integration may improve prediction of species and lineage responses to future climate change more than individual traits alone, particularly when analyses incorporate effects of phylogenetic relationships. The South African genus Pelargonium contains divergent major clades that have radiated along the same seasonal aridity gradient, presenting the opportunity to ask whether patterns of evolution in mean leaf trait values are achieved through the same set of coordinated changes among traits in each clade.

Methods: Seven leaf traits were measured on field-collected leaves from one-third of the species (98) of the genus.

Low levels of climate niche conservatism may explain clade diversity patterns in the South African genus Pelargonium (Geraniaceae).

Premise Of The Study: Sharp climatic gradients in South Africa and in particular in the Cape Floristic Region (CFR) provide a diversity of niches over short distances that may have promoted ecological diversification in local clades. Here we measured the extent to which closely related species occupy divergent climates and test whether niche lability is correlated with higher species diversity in the genus.

Method: We integrated phylogenetic information and environmental niche models (ENM) to assess the levels of climate niche conservatism.

Upper Cretaceous woods from the Olmos Formation (late Campanian-early Maastrichtian), Coahuila, Mexico.

Premise Of The Study: The Olmos Formation was part of a system of deltas that existed in the southern portion of the Western Interior of North America during the Campanian-Maastrichtian. The paleofloristic composition from the northern portions of the Epicontinental Sea is relatively well known, but less intensive exploration in the south has precluded more detailed floristic comparison across the entire latitudinal span of the Sea. The Olmos Formation flora, with more than 100 different leaf morphotypes so far recognized and several wood types, has the most diverse Cretaceous fossil plant assemblage in Mexico and represents a valuable opportunity for comparative studies.

Integration of vessel traits, wood density, and height in angiosperm shrubs and trees.

Premise Of The Study: Trees and shrubs tend to occupy different niches within and across ecosystems; therefore, traits related to their resource use and life history are expected to differ. Here we analyzed how growth form is related to variation in integration among vessel traits, wood density, and height. We also considered the ecological and evolutionary consequences of such differences.

Wood anatomy and wood density in shrubs: Responses to varying aridity along transcontinental transects.

Wood density plays a key role in ecological strategies and life history variation in woody plants, but little is known about its anatomical basis in shrubs. We quantified the relationships between wood density, anatomy, and climate in 61 shrub species from eight field sites along latitudinal belts between 31° and 35° in North and South America. Measurements included cell dimensions, transverse areas of each xylem cell type and percentage contact between different cell types and vessels.

Hydraulic integration and shrub growth form linked across continental aridity gradients.

Both engineered hydraulic systems and plant hydraulic systems are protected against failure by resistance, reparability, and redundancy. A basic rule of reliability engineering is that the level of independent redundancy should increase with increasing risk of fatal system failure. Here we show that hydraulic systems of plants function as predicted by this engineering rule.