(Umbilicariaceae), a new lichen species from the canopy of .

Timdal, Reese Næsborg & Bendiksby is described as a new species occupying the crowns of large trees in California, USA. The new species is supported by morphology, anatomy, secondary chemistry and DNA sequence data. While similar in external appearance to , it is distinguished by forming smaller, partly coralloid squamules, by the occurrence of soralia and, in some specimens, by the presence of thamnolic acid in addition to friesiic acid in the thallus.

Hydraulic constraints modify optimal photosynthetic profiles in giant sequoia trees.

Optimality theory states that whole-tree carbon gain is maximized when leaf N and photosynthetic capacity profiles are distributed along vertical light gradients such that the marginal gain of nitrogen investment is identical among leaves. However, observed photosynthetic N gradients in trees do not follow this prediction, and the causes for this apparent discrepancy remain uncertain. Our objective was to evaluate how hydraulic limitations potentially modify crown-level optimization in Sequoiadendron giganteum (giant sequoia) trees up to 90 m tall.

Contrasting drought-response strategies in California redwoods.

We compared the physiology and growth of seedlings originating from different Sequoia sempervirens (D. Don.) Endl.

Taxonomic revision of the Lecania cyrtella group based on molecular and morphological evidence.

This investigation elucidates relationships within the Lecania cyrtella group (Ramalinaceae, lichenized Ascomycota) by employing morphological, anatomical and molecular methods. The morphological studies included eleven species of Lecania, L. cyrtella, L.