ENDOGEN n.
throughout the whole diameter, not forming annual layers, and with no distinct pith. The leaves of the endogens have, usually, parallel veins, their flowers are mostly in three, or some multiple of three, parts, and their embryos have but a single cotyledon, with the first leaves alternate. The endogens constitute one…
EXOGEN n.
ng, if at all, by the animal addition of a new layer to the outside next to the bark. The leaves are commonly netted-veined, and the number of cotyledons is two, or, very rarely, several in a whorl. Cf. Endogen. Gray.