The local horticultural world is abuzz over Maejo University’s air-purifying Philodendron, whose leaf sells for a whopping 20,000 baht while an entire plant costs a pocket-digging 50,000 baht. The Philodendron (Philodendron billietiae Croat) is coveted for its leaves, each of which comes in its own extraordinary design – the more desirable the design, the more expensive the leaf. This photo