$T.S.$ of stem of Cucurbita can be identified from the $T.S.$ of sunflower stem by the presence of
Bicollateral vascular bundles
Conjoint vascular bundles
Scattered vascular bundles
Cambium in the vascular bundles
Age of a tree can be estimated by :
Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by
Vascular bundles having xylem and phloem sit at the same radius is termed as
Ring bark is present in