Eight conifer taxa belonging to four families, i.e., Pinaceae, Taxodiaceae,
Araucariaceae and Cupressaceae were collected during spring and summer of 2003
season to compare the anatomical structure of both leaves and stems and evaluate
their systematic significance. The obtained results could be summarized as follows: Regarding the leaf structure, stomata type and their position, presence or
absence of the hypodermis and endodermis; number of resin ducts, differentiation of
mesophyll tissue and forms of transfusion tissue were varied within the studied taxa.
Taxodium distichum leaves are characterized with differentiation of mesophyll tissue
and spongy parenchyma, while, in the other studied taxa there is no such distinction.
Needles of Pinus species are characterized with largest number of resin ducts,
presence of the endodermis and infloding parenchyma cells in the mesophyll tissue
compared with the other studied taxa . . Concerning the stem structure, the number and arrangement of resin ducts,
number and thickness of eipthelial cell layers varied among the studied taxa. There
are two types of resin ducts in Pinus species, .i.e., primary and secondary which are
found in cortex and xylem tissue, respectively, while in other examined taxa were
found only primary resin ducts. The largest number of resin ducts with scattered
arrangement was found in Araucaria. The largest diameter of resin ducts with more
number of epithelial cell layers was found Juniperus communis, while, the smallest
diameter of resin ducts was found in Thuja. These characters may be used as a
guide for classification of conifer families. The obtained results indicate also similarity of Taxodium with the
Cupressaceae family in certain anatomical leaf and stem characters, i.e., absence of
hypodermis and endodermis, number of resin ducts. Its pattern and structure in the
leaf, as well as number and arrangement of resin ducts and its position in the stem.