Complex sentence: More than 20% of the vascular plants found are endemic to Morocco, some 607 species, and of these, "Silene" and "Teucrium" each contains over 25 endemic species.
Split into simpler sentences: More than 20% of the vascular plants in the country (some 607 species) are endemic to Morocco. Of these, the genera "Silene" and "Teucrium" each contain over 25 endemic species.