Towering redwoods and lanky jungle vines hoist water from the soil to their lofty leaves through a tubelike tissue called the xylem. In early plants, which reached just a few centimeters and lived ...

Cross section of hypocotyl of 8-week-old Arabidopsis thaliana. The ovac mutant displays enhanced secondary vessel differentiation (red) at the expense of parchenchyma cells. Images A2 and B2 show the ...

(via SciShow) Trees are dead inside. It's true: the xylem tissue that supports their trunks technically isn't alive. Archaeologists hate that because this problem, the old wood problem, can cause ...