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Home > All Images > 1990 > February > 5 Feb 1990

Images Dated 5th February 1990

Choose from 14 pictures in our Images Dated 5th February 1990 collection for your Wall Art or Photo Gift. All professionally made for Quick Shipping.

False-colour SEM of oak heartwood Featured 5 Feb 1990 Image

False-colour SEM of oak heartwood

False-colour scanning electron micrograph of a horizontal section through oak heartwood, the wood (secondary xylem) of the tree Quercus robur. The image shows the cut end of a tracheary vessel which has become blocked by papery bladder-like ingrowths known as tyloses (yellow). In young sapwood the vessels carry water & nutrients from the roots to the leaves, but after a few years they become blocked & no longer carry sap. Large vessels like this occur in early (spring) wood; late-wood vessels are much smaller. The tissue surrounding the vessel is wood parenchyma, an unspecialised matrix tissue. Oak is classified as a hardwood. Magnification: x100 at 6x4.5cm size