A blue-black plant pigment having a blue-green alcohol solution; found in all higher plants WordNet 3.0 & Open English WordNet

Chlorophyll a is a specific form of chlorophyll used in oxygenic photosynthesis. Wikipedia

Chemical compound Wikidata

The universal chlorophyll (C55H72MgN4O5) essential to the dominant oxygenic photosynthesis I process, present in all eukaryotes, cyanobacteria, chromists, and prochlorophytes that photosynthesize, and that contributes to the observed green color of these organisms. Wiktionary