Dicotyledons
This name is now more generally used than Exogens. It is one of the two classes into which Phaenogamous or flowering plants are divided. The distinguishing characteristics may be briefly stated: Flowers with the organs mostly in fours or fives. Embryo with opposite cotyledons. Leaves usually with netted veins. Stem with bark, pith, and interposed wood; when perennial, increasing annually in diameter by a layer of wood, added to the outside of the old wood, and another of bark, added to the inside of the old bark.