| from the June 9, 2008 Newsletter, issued from near
Natchez, Mississippi: SILVERINESS IN CHERRYBARK OAK LEAVES Late afternoon sunlight slanting in from the west very prettily lights up trees directly before my porch. One feature of the view likely to catch anyone's attention is that some trees are emerald green while others are silvery green, as you can see below:
That picture looks like I've used PhotoShop to accentuate the green tree's greenness, but that's just the effect of late-afternoon sunlight. The green tree on the left is a big American Elm miraculously still unaffected by Dutch Elm Disease. The silvery-leafed tree at the right is a Cherrybark Oak, QUERCUS PAGODA. I got curious about what was behind the Cherrybark's silveriness so I went
and looked. The silveriness appears to be caused by abundant, minute, silvery hairs of a
special kind mantling the leaves. Books refer to these special hairs, so thick on the
leaves' undersurfaces that the undersurfaces have a velvety feeling, as
"stellate." "Stellate" means "star-like," and the
Cherrybark's hairs are star-like because they often consist of several sharp hairs arising
from a single point on the leaf-blade surface, like the rays of light that supposedly
emanate from stars. |
