Noun
protoxylem (plural protoxylems)
The first xylem to form in a plant.
Development Patterns of xylem development: xylem in brown; arrows show direction of development from protoxylem to metaxylem. Source: Internet
Functionally, protoxylem can extend: the cells are able to grow in size and develop while a stem or root is elongating. Source: Internet
In appearance protoxylem is usually distinguished by narrower vessels formed of smaller cells. Source: Internet
The first xylem to develop is called 'protoxylem'. Source: Internet
The metaxylem is thus on both the peripheral and central sides of the strand with the protoxylem between the metaxylem (possibly surrounded by it). Source: Internet
The protoxylem is thus found in the central core and the metaxylem in a cylinder around it. citation This pattern was common in early land plants, such as " rhyniophytes ", but is not present in any living plants. Source: Internet