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Dicot stem
Monocot stem
Broad pith
Weak stem
Monocot fiber sheaths
Ordinary cortex
Aerenchyma hypodermis
Aerenchyma cortex
Aerenchyma cortex 2
Stem endodermis
Palisade cortex
Cortical bundle
Capped cortical bundles
Collapsible cortex
Perimedullary fibers
Conjunctive tissue, paren.
Torn pith
Hollow pith
Medullary bundles
Typical dicot bundle
Vascular ring
Typical monocot bundle
Amphivasal bundle
Corn vascular bundle
Clintonia bundles
Protoxylem
Metaxylem
Metaxylem parenchyma
Metaxylem fibers
Internal phloem
Internal phloem, mag
Developing metaxylem
Primary phloem
Phloem fiber cap
Developing fibers

Fig. 11.5-2. Transverse section of foxglove stem (Digitalis). Most species of dicots have a ring of vascular bundles, but a few like this foxglove have a more or less continuous ring of vascular tissue. The tissues are still in the typical arrangement (with protoxylem innermost, then metaxylem, metaphloem, a tiny bit of collapsed [and not visible] protophloem). The cap of primary phloem fibers is also a continuous ring.