Q:

Word for "parts of a plant"

Is there a word that means “plant part”? 
As in, “member/organ is to body as ______ is to plant”. 
Root, stalk, leaf, petal, stamen, are all what?

A:

structure wiki/botany
Plant morphology or phytomorphology is the study of the physical form and external structure of plants.  wikipedia
As in:

As in, “A member/organ is to the human body as a structure is to a
  plant”.

and/or  
Plant organs include the leaf, stem, root, and reproductive structures.
Meaning that plant parts can also be called organs!

