How would you depict flora and fauna on a planet where photosynthesis is vastly more efficient?

Photosynthesis as we know it is not very efficient. Plants in the real world generally only absorb a tiny amount of the light spectrum and most of the energy from that is basically wasted on metabolic functions. A commonly cited figure in this regard is that wheat is only about 3.6% efficient in converting light to grain (though the actual efficiency of photosynthesis is a little higher, at least 6% for some plants). <br><br>So what would a planet look like if photosynthesis was highly efficient, with plants able to convert 60%, 80%, maybe even 100% of the light energy they absorbed into chemical energy? Given that photosynthesis is the basis of food chains and that plants produce oxygen as a byproduct, what would flora and fauna look like on such a planet?#####