Mesarch xylem is the condition in which protoxylem in a primary xylem strand develops first in the centre of the strand and continues to develop both centrifugally and centripetally, e.g. in shoots of ferns.

What is the meaning of Mesarch?

: having metaxylem developed both internal and external to the protoxylem.

What is Mesarch in botany?

adjective. Botany. (of a primary xylem or root) developing from both the periphery and the center; having the older cells surrounded by the younger cells.