The sugar apple is of great economic importance to the country,
however, information on the anatomical and morphological
aspects of Annonaceae family seeds is limited to a few species
and the anatomical studies refer to very few seeds. Using histological
techniques and microscopy, Annona squamosa L. seeds
were studied with regard to their anatomical characteristics.
In general, they presented the typical anatomical patterns of
seeds of the Annonaceae family. The multilayered testa was
comprised of exo-, meso- and endotestas, with the presence
of longitudinal and oblique fibers. The embryo was small and
straight with moderately developed embryonic axis, rudimentary
plumule and flat and thin cotyledons, wherein one could
observe the procambium. In particular, the perichalaza was
observed in the medium longitudinal plane of the endotesta
with more than two rows of vascular tissue. The tegmen or inner
integument was collapsed. The micropylar plug was tapered,
woody and composed of transverse fibers; a fracture line was
also observed. The ruminate endosperm interfered with both
the inner and external integuments. Oleiferous idioblasts were
observed at the outer edges of the ruminations