The staff of flowers (XGtE, p. 139) is an intentionally weak item, but depending on how the rules are interpreted it seems like it can be very useful.
Since certain flowers grow as buds on trees, will the staff grow an entire tree just to create a requested flower?
For example, if I specify that I want a Cherry Blossom and aim the staff at a nearby patch of dirt, will it create an entire Cherry Tree because I asked for it?
As 1600hp notes, getting a full-size tree out of the Staff of Flowers is probably not intended, especially as it would substantially duplicate the functionality of the rare, single-use Feather Token (Tree).
(You could argue that a typical cherry tree isn't quite the same thing as the 60 foot oak created by the Feather Token, but there are other flowering trees that can grow much larger. How about a liriodendron (tulip tree), for example?)
That said, creating a cherry blossom without a tree feels weird, too. Where would it grow, then? Just flat on the ground? So I'd be inclined to let it create a tree, if only so that the blossom won't look out of place.
That said, nothing in the description of the staff says that it has to be a full-size mature tree. So a reasonable DM could well rule that the staff creates a small cherry tree sapling, maybe a few handspans tall, with a single blossom on it.
That'd be as biologically plausible as anything the staff does (real trees can and do grow and flower like that, especially if their growth is naturally or artificially stunted; just Google "bonsai cherry tree" for some examples) and seems mechanically balanced.
And you do get a real cherry tree out of it — you'll just have to wait a few years for it to grow to full size. :)
You can look at this problem from a few different angles, and you'll get the same result.
The argument that this should work relies on the unspoken theory that a cherry blossom cannot grow without a cherry tree. But this is a magic staff! It's already growing whatever kind of flower you want without a bulb or seed or what have you.
The ability's wording ("cause a flower to sprout from a patch of earth or soil") indicates that the flower is sprouting from the target location. The fact that the wording isn't something along the lines of "cause a flowering plant to sprout" should indicate that the intent is that the flower itself is a solitary object.
While the magic item rarity system isn't always perfect, allowing this use of the Staff of Flowers would far overshadow the magic item whose primary purpose is to grow trees: the Feather Token (Tree). This rare, single use item only grows a tree. That's all it does. You probably shouldn't allow a common, reusable, rechargable item to do the same.
