Identify the monocot stem characters.
I. Exarch xylem 
II. Absence of medullary ray
III. Presence of bundle sheath 
IV. Scattered vascular bundles

The type of xylem found in stems is endarch. Endarch xylem refers to the arrangement of xylem elements within the vascular bundles of stems, where the earliest-formed xylem is located towards the center or interior of the bundle, and the later-formed xylem is located towards the periphery or exterior of the bundle.