Encyclopædia Britannica, Ninth Edition/Acrogenæ

For works with similar titles, see Acrogenae.

Acrogenæ is the name applied to a division of acotyledonous or cryptogamous plants, in which leaves are present along with vascular tissue. In the higher divisions of Acrogens, as ferns and lycopods, the tissue consists of scalariform vessels, while in the lower divisions spiral cells are observed, which take the place of vessels. The term Acrogen means summit-grower, that is, a plant in which the stem increases specially by the summit. This is not, however, strictly accurate.