دراسة تصنيفية ومرفولوجية لنوعين من جنس ذنب الخيل Equisetum L. من فصيلة Equisetaceae ينتشران في بعض مناطق اللاذقية- سورية

At this study, two species of genus Equisetum L. have been recorded, that they were: Equisetum telmateia L. and Equisetum ramosissimum Desf. E. ramosissimum Desf. was recorded for the first time in Lattakia. The morphological features were used to separate two species: ( number of the scaly leaves in the node area, shape of the sheath, and number of its teeth, number of the grooves at the stem, length of the strobilus and its color, length of the lateral branches). This study showed that: the spores had three coats, the exosporium rounded by the spore like bars with a wide terminal that called: elaters. Also showed obvious difference in measurements the strobilus and the shapes of sterile and fertile stem.