Practice question

Species richness counts based on Kew Royal Botanic Gardens checklist place Orchidaceae at approximately 28,000 species plus 763 genera surpassing Asteraceae around 23,000 and Fabaceae 19,500, making orchids largest. Orchids achieve success via epiphytism in tropical canopies, elaborate zygomorphic flowers with labellum, column fusion of androecium gynoecium, pollinia enabling single pollination deposit many pollen grains, dust-like non-endospermic seeds requiring orchid mycorrhiza for germination, and deceptive pollination strategies mimicking insects. Poaceae economically crucial but less speciose. Consequently Orchidaceae recognized as largest family, though Asteraceae rivals depending on circumscription and recent discoveries.