Not arbitrary: consciousness is a defined word with historical meaning. "Consciousness comes from the Latin word conscious, which means "knowing with" or "having joint knowledge." The term evolved in English during the 17th century, with its modern meaning relating to awareness of one's own mind first appearing in the late 1600s."

You have arbitrarily redefined consciousness, implicitly by context to include any response to the environment. What good is epistemology if a plant's hormonal action implies self awareness?

Edit: Imagine, if you will, that the stream of consciousness using language to tie a plant's hormonal action to self awareness, e.g., words like "plants know when" is just as much of a cognitive and emotional hallucination as the most sublime sounding gibberish produced by an LLM.