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SEM photographs of Lupinus arboreus
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The photographs below have been taken using a scanning electron microscope (SEM). This allows us to take photographs at high magnifications while having a good depth of field to show more details of 3-dimensional objects.
The samples were first dried of their water content and then coated with a layer of graphite before being placed in the electron microscope.
1. Surface view of the upper leaf surface of a mature Lupinus arboreus leaf.
 200x |
Leaf hairs and stomata are visible
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2. Surface view of the lower leaf surface of a mature Lupinus arboreus leaf.
 200x |
Notice the difference in leaf hair and stomatal density
compared with the upper surface of the leaf.
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3. A single stomate.
 2000x |
Notice that the stoma is in a shallow pit, this will
help to reduce wind speed across the stomata and therefore slow transpirational water
losses. The 'rough' texture is caused by the presence of wax fibres making up the cuticle.
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4. Surface view of lower surface of Lupinus arboreus leaf showing the waxy cuticle
 8000x |
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5. Base of a leaf hair.
 2000x |
The groove in the hair will increase its strength to
weight ratio. There may be other advantages of the groove but I don't know what they are!
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6. Transverse section of testa.
 Blue lupin Transverse section of testa - 200x |
The next two photographs show the difference in the thickness of the testa in Lupinus arboreus compared with a commercial variety of lupin. Although they are about the same thickness there is an obvious difference in the density of the outer layer, this contributes towards the greater dormancy period of Lupinus arboreus. The penciled lines on the right of each photograph indicate the thickness of the testa. |
 Lupinus arboreus Transverse section of testa - 200x |
7. Surface of testa.
 Blue lupin Surface view of testa - 2000x |
The next two photographs show the
difference in the surface of the testa in Lupinus arboreus compared with the
commercial variety, blue lupin. The commercial variety has a much greater porosity which
will contribute towards its faster germination rate when compared with that of Lupinus
arboreus. The thicker testa makes a significant contribution to the maintenance of dormancy in L.arboreus. |
 Lupinus arboreus Surface view of testa - 2000x |
Photographs are the property of G.J.McKenzie and may not be used for commercial purposes without my prior permission.
