WOW. Severus Snape as a large, loud, grumpy, slightly frightened plant is an awesome thing to read! What a hugely creative fic this is, in so many ways! I love the humor, the endlessly elaborated descriptions of the GL plant and the long process of rescuing it.
I held my breath when Snape "sleep-walked" into the house that night on his poor little drying-out roots, and was worried he wouldn't make it back into the pot without suffering a setback.
There was an edge of pathos all the way through, because of the oddness of a person-turned-plant, that despite all the humor there too, gave the fic a convincing slightly science-fictiony undertone. This was perfect for the topic, the Victorian greenhouse setting, and the way Neville and Harry have to find their way through the challenge all by themselves. Harry and Neville lounging on the wicker garden furniture in the glasshouse, reading Sherlock Holmes to the giant exotic plant, added even more to the elegant and slightly ominous atmosphere.
The Epilogue dispelled this so beautifully at the end with the sunny cameraderie of the three partners. I must say, it was fun to see Snape come out of this with a deeper love of plants - almost some fellow-feeling, lol - and an appreciation at last for Neville's skills!