Plant Plumbing

Swiss cheese plant Monstera deliciosa is commonly grown as a decorative house plant but in its native Mexican rainforests it's a rampant climber, using its adventitious roots to cling to trees and climbing in much the same manner as ivy in temperate woodlands. Those holes in the Monstera leaf, whose resemblance to holes in Swiss cheese account for its name, let flecks of sunlight filter through to the layers of leaves below, all of which are transpiring water from their surface. If you cut a section through the stem, you can see the internal pipework that conducts water from the roots to the leaves.

In this transverse section of adventitious root, stained with fluorescent dyes that colour dead, woody cell walls yellow and living cellulose cell walls blue you can see the various cells that conduct liquids up and down the root. Embedded in that thick-walled strengthening tissue that gives the root (which in this case is used for clasping tree trunks and branches - this plant is a tropical climber)  rigidity and are fluorescing yellow, are large vessels that conduct water in a continuous tensile column from the roots to the leaf, pulled upwards by evaporation from the leaf surface. The smaller tubes, lined with a layer of blue-fluorescing cell walls, may be resin ducts. The outer cells on the left, part of the ring of small bundles of living cells that encircle the root, are the phloem cells that conduct sugars manufactured by photosynthesis in the leaf to other parts of the plant. Swiss cheese plants are such familiar items of interior decor that they hardly attract a second glance, but they have extraordinary hidden beauty, only visible under the microscope