When the set Legends was released in 1994, this card was given an errata to make its ability require a target. This made it incredibly powerful alongside cards that could not be targeted or any creatures with protection from green. In later years, this would include creatures such as Troll Ascetic with hexproof.
In recent years, the errata was reversed and revised to be something that was much closer to its original text. That way it would no longer target. This "nerfed" its power a bit, but it's still a strong card. If you can find one in near-mint condition, it's a rare and expensive card worth adding to your collection.
Drop of Honey actually is on the Reserve List. Compared to others on the list, it's now just very good rather than extremely powerful. With the errata that once made it immensely good no longer in play, it probably doesn't need to be on that list any longer.
Still, it's hard to see this card being reprinted in today's Magic, even were it not on the list. As it stands, with its relative rarity, this card can command $500 or more a copy. If you have a copy lying about, be lucky that you do, as it's one of the more expensive Magic cards around!
Have you ever played Drop of Honey?
~ Phoenix <3