The part of speech for "wisteria" is a noun. It refers to a type of flowering plant known for its hanging clusters of flowers. The term "wisteria" is used to denote the plant itself, as well as the flowers and vines that belong to this genus. This classification as a noun is due to its function as a subject or object in a sentence, rather than serving as an adjective, verb, or other part of speech.

Wisteria is a noun because it is a proper noun, which is a noun that names a specific person, place, or thing. In the case of wisteria, it is a specific type of plant. Proper nouns are always capitalized, which is consistent with the use of "wisteria" in sentences. For example, "The wisteria vine is in full bloom this season" or "I planted a wisteria tree in my backyard." In these sentences, "wisteria" is the subject or object, making it a noun.

Data from botanical and linguistic sources support this classification. According to the American Heritage Dictionary of the English Language, "wisteria" is defined as "any of several climbing vines of the genus Wisteria, of the leguminous family, having pinnate leaves and large, showy, fragrant clusters of flowers." This definition clearly places "wisteria" in the category of nouns, as it refers to a specific type of plant.

Additionally, the Oxford English Dictionary (OED) lists "wisteria" as a noun, describing it as "a genus of climbing leguminous plants with pinnate leaves and large racemes of showy flowers." The use of "genus" and "plants" in the definition further emphasizes the noun nature of "wisteria.

In conclusion, "wisteria" is a noun because it refers to a specific type of plant and functions as a subject or object in sentences. This classification is supported by botanical and linguistic definitions, which consistently identify "wisteria" as a noun.