A nongreen stem branch that grows obliquely or sometimes grows horizontally inside the soil and then comes out of the soil as a branch is called

The weak stemmed plants which can climb with the help of thorns, spines, prickles are

Give scientific reasons : Though Ginger is gram in/under the soil. It is a stem not a root.

Phylloclade of Opuntia is stem because

Rhizome of ginger is like the roots of other plants that grows underground. Despite this fact ginger is a stem and not a root. Justify.