I understand what you're saying but i disagree that there is any proper defining of the concept. The few scientist that attempt to study it can't even agree on what it even is.
I agree that my example where far out, they are supposed to be to represent ideas outside the conventional box. I don't literally believe grass is conscious. I recognize that if i/we don't know, then i/we don't know. In the face of something we don't know the nature off, the requirements for, the purpose it serves i prefer to remain open to every option.
I know Wikipedia isn't a scientific research paper but i expect that if there really is a agreed upon scientific answer it wouldn't be like it currently is:
"Consciousness, at its simplest, is awareness of internal and external existence. However, its nature has led to millennia of analyses, explanations and debate by philosophers, theologians, and all of science. Opinions differ about what exactly needs to be studied or even considered consciousness. In some explanations, it is synonymous with the mind, and at other times, an aspect of mind. In the past, it was one's "inner life", the world of introspection, of private thought, imagination and volition. Today, it often includes any kind of cognition, experience, feeling or perception. It may be awareness, awareness of awareness, or self-awareness either continuously changing or not. The disparate range of research, notions and speculations raises a curiosity about whether the right questions are being asked."