Final answer:
Specifics about Melinda's final tree and the symbol of hope added to her art piece cannot be determined without the correct literary text.
Step-by-step explanation:
The question pertains to the characteristics of Melinda's final tree, as described in a work of literature. The specifics about Melinda's final tree art are not given in the provided reference materials, and it seems the question refers to a book or text not included in the information given. Without the correct textual reference, giving specific details on the specific characteristics or the symbol of hope she adds to her final piece of art would not be accurate.
Literature often uses trees and elements of nature as symbolic representations, and they could represent a wide range of concepts such as growth, fertility, stability, or renewal. In literature, characters or objects might symbolize hope by embodying new beginnings, resilience, or a bright future. Given that the text in question isn't specified, one could only provide general interpretations which may not be applicable to Melinda's final tree.