ANATOMÍA E HISTOQUÍMICA DE LA CORTEZA DE CINCO ESPECIES DE MORACEAE

Abstract

We have analyzed and compared the anatomical and histochemical features of the
secondary phloem and the peridermis of
four species of Ficus and Morus celtidifolia.
Anatomical features shared by the four Ficus species here studied are: sieve elements
of polygonal shape arranged in radial clusters are abundant. Heterogeneous, stratified
rays are formed by square and tangentially
dilated cells; rays form irregular fans. A
monostratified periderm is composed by
a layer of sclereids in the pheloderm and a
suberized phellem with wall thickenings of
polyphenolic origin. Parenchyma cells
contain cubical and romboidal crystals
and druses. Laticifers are non articulated
and branched. M. celtidifolia rays do not
form fans as in Ficus; axial parenchima dilates and packages of sclereids appear towards the periderm. Heterogeneous rays are
not stratified, laticifers are non articulated
and shorter than in Ficus. Periderm structure is similar, but thicker, than in Ficus.
The bark of the species analyzed in this work
has been traditionally used for making an
“amate” paper of higher quality than that
produced with the bark of other species. The
results of the histochemical analysis show
a slightly lignified structure, abundance of
starch, pectins and water soluble carbohydrates towards the periphery, as well as non
lignified fibers in all the species studied.
These features can be related to the ease of
paper manufacture, to adherence and agglutination properties, to the high quality
of the end product and could explain the
intensive use given to these species during
precolumbian times.