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.