Vascular Systems in plants – an introduction to plant anatomy Cells & Tissues. Organization into structural entities.

Endodermis Pericycle primitive vascular plants Lycopodium gnidiodes

primitive vascular plants Lycopodium claviatum

primitive vascular plants PROTOXYLEM PROTOXYLEM PHLOEM Detail of a cross section of the stem of Psilotum Psilotum has no leaves or roots!

primitive vascular plants TRABECULA XYLEM PHLOEM Trabeculae are modified endodermal cells – pericycle surround vascular bundle.

primitive vascular plants ENDODERMIS PERICYCLE PHLOEM Rumohra

PROTOPHLOEM PHLOEM FIBERS FIBERS Encephalartos. Gymnosperm

Araucaria (Gymnosperm) TRACHEIDS RAY CAMBIUM PHLOEM PHLOEM Araucaria (Gymnosperm)

INTERNAL PHLOEM EXTERNAL PHLOEM Cucurbita

Zea mays Monocotyledon. (Atactostele) highly advanced

Nymphoides stem Hydrophytes have a reduced xylem component in the vascular system. Here, only a few XYLEM VESSELS are visible. The phloem on the other hand appears to be well-developed, and consists of sieve tubes companion cells and phloem parenchyma. I Several ASTROSCLERIEDS can be seen interspersed with the ground parenchyma

Ligustrum (Privet) Leaf Advanced foliage leaf, dicotyledon. Note mesophyll divided into upper palisade and lower spongy layer. Smaller veins (like these) are embedded within the mesophyll, between palisade and spongy layers. These are MINOR veins

Zea mays leaf

The pine leaf vascular bundle cambium sunken stomate The pine leaf In Gymnosperm leaves such as the pine leaf, the vascular system is reduced to the central region. You should be able to see two vascular bundles in this example. The xylem is composed of TRACHEIDS and the phloem of SIEVE CELLS and ALBUMINOUS CELLS. endodermis vascular bundle endodermis