Definition
noun
The part of the primary xylem that is last to develop from the procambium, and characterized by weblike or pitted surfaces and broader tracheary elements than the protoxylem
Supplement
In vascular plants, the major conducting tissues are xylem and phloem. The xylem tissues may be classified as primary or secondary depending on where they are derived. The primary xylem is the type of xylem produced from the primary growth. It differentiates into two parts: (1) protoxylem and (2) metaxylem. The protoxylem is the first one to form followed by the metaxylem (thus, the name). Both protoxylem and metaxylem are found in the primary vascular bundle, and involved in the conduction of water and minerals towards the apical shoot. They are produced by the procambium. Both of them contain tracheids, vessels, and parenchyma. However, the metaxylem has more tracheary elements than the protoxylem. Furthermore, the lumen of tracheary elements of the metaxylem is larger than that of the protoxylem. This makes the metaxylem more efficient in conduction than the protoxylem. The metaxylem also has few fibers, which are lacking in protoxylem. It is not capable of stretch (unlike protoxylem). However, it is not subjected to strain or stress.
Word origin: meta– (“later”) + xylem, from Greek xúlon (“wood”)
See also:
Dictionary > Metaxylem
You will also like...

IQ, Creativity and Learning
Human intelligence provided the means to utilize abstract ideas and implement reasoning. This tutorial takes a further l..

Circulation
The circulatory system is key to the transport of vital biomolecules and nutrients throughout the body. Learn about the ..

Gene Action – Operon Hypothesis
Learn how the way genes control and determine every aspect of the body. This lesson uses lac operon as an example. ..
..

Physiological Homeostasis
Homeostasis is essential to maintain conditions within the tolerable limits. Otherwise, the body will fail to function p..

Human Reproduction and Fertilization
For human species to obviate extinction, reproductive mature adults should be producing viable offspring in order to con..

Principles of Hormonal Control Systems
Hormones are essential in the regulation of the activity of the various biological systems of the human body. The ineffi..