Cohesive Lift of Sap in the Rattan Vine

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Abstract
It is clear that the bioengineering of a tree is amazingly suited to deal with liquid under tension. However, the mechanism by which the plant copes with certain situations is incompletely understood. Nucleation and cavitation are a regular part of life cycle of northern forest trees. How is this massive gas seeding mended, and is it really true that a redwood or eucalyptus 100 meters tall maintains a sap pressure at the top of[long dash]20 atmospheres? We do not know by direct meaurements what hydrostatic pressures the transpiring plant must buck in the soil, nor can we, with any accuracy, measure negative pressures in the trees. So, we have no direct knowledge of hydrostatic gradients in these structures. There is little reason to doubt that a variety of microporous structures, such as clay, soil, xylem, or gelatine, may become squeezed by the cohesive forces of the enclosed water, but the empirical study of all of these phenomena is deadlocked by lack of accurate measuring techniques. The free-for-all, charming old problem of how sap ascends tall trees still presents a wealth of unsolved questions to challenge the experimental ingenuity of future workers.