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Name: Steven
Status: educator
Grade: other
Location: Outside U.S.
Country: Brunei

Question: We know that from our microscope observation that mango
leaves have lots of stomata in their lower section of the leaves. My
question are: Is there any stomata in the upper section of the mango
leaves? (According to our observation, there is not any). However we
test cobalt chloride paper to test for transpiration, the paper
changes color to indicate water is given out in the upper section

of the mango leaves. Does it means that there is stomata in the
upper section of the leaves?
Dear Steven,

I would trust your observations.  If you see no stomata, then there probably 
are not any.  It is possible that the upper section of the leaf is slightly 
porous to water regardless of the presence of stomata or not.  Could the 
water come from the edge of the leaf through hydathodes, stomata-like openings 
at the edge of the leaf?

Jim Tokuhisa, Ph.D.
Assistant Professor

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