Types of vascular bundles

Short, sweet, and presentable details of the following basic types of vascular bundle.
Collateral
Bicollateral
Open: the presence of cambium
Concentric
Radial: on the different radius
with diagram

1. Yusra M. Khatib
Assistant Professor (Botany)
K. M. E. Society’s
G. M. Momin Women’s College

2. Types Study material Characteristics
Conjoint, Collateral, and OpenSunflower stem Conjoint-XylemandPhloemonsame
Axis
Collateral-phloemontheoutersideofthexylem
towardstheperiphery.
Open-cambiumispresent
Originofxylemisendarch-protoxylemtowardsthe
centerandmetaxylemtowardstheperiphery
Conjoint, Collateral, and
Closed
Maize stem Closed-cambiumabsent
xylemisendarch
‘Y’shaped
Consistsoftwolargemetaxylemvesselsand
protoxylemconsistingofannularandspiral
vessels.

3. Types Study material Characteristics
Conjoint, Bicollateraland
open
Cucurbita stem Bicollateral-Phloemonlateralsideofxylemi.e.
onbothsides
Endarchxylem
Betweentheouterphloemandxylemispresent
outercambiumandbetweenthexylemandinner
phloemispresentinnercambium.

4. Concentric
Type Study materialCharacteristics
Amphicribralor HadrocentricFern rachis 4to6vascularbundleswhicharearrangedinan
arc.
Somevascularbundlesarelargeandsomeare
small.
xylem in the center and phloem surrounding it.
Xylemisexarch-Metaxylemisinthecenterwith
protoxylemtowardstheperiphery.
Leptocentricor AmphivasalDracaenastemScattered
Phloemissituatedatthecenterofthe
vascularbundleandissurroundedbyxylem.

5. Radial
•Arrangedalternately
•xylemononeradiusandphloemonthenextradii
•metaxylemistowardsthecenterandtheprotoxylemtowardsthe
periphery.Thus,originofxylemisexarch.
•Maizeroots.
•Closed