You can. The catch is, you can only have 1 in your invintory at a time. meaning you can only pick up 1 at the tree of styx at a time. There is a few loopholes however. If you have a leaf in the alchemy pot...... you can pick up another..... then take the first 1 out of the pot. or...... you can pick 1 up at the tree (or buy it) and then get more from chests, as chests arent bound by the 1 leaf rule.
I use more ellipses then any person should ever need to..... ever. (GH3....... 5* expert career songs: 32)
That certainly can't work in this game; you never bench anyone. Might be thinking of 7.
You gotta be at the Tree at dawn. Best to show up a bit early, and putz around until sunrise. Also, you cannot already own a Leaf. (You CAN, however, fool the game by mixing it with something in the Alchemy Pot, then canceling the mix after you get your free leaf.)
At the right time, a patch of ground will glow. That's the leaf. Grab it.
With this, you can have 2 leaves at all times. Until you get the Instant Alchemy Pot Ugprade from the postgame Trial rewards, anyway.
It is possible to get more than 2, if you know how to go about it. First, have the two. Then, get whatever ones can be found in chests. Then, hope against hope that the high-end tree enemies, which are capable of dropping Yggdrasil Leaves, oblige you by doing so. (I've never gotten one in this particular manner.)
Just know that having that many means you can't pick up the free one until you're out (or are down to one, and put it in the alchemy pot temporarily). Nor can you buy them at the bazaar unless you do the same thing.
I never really went for overstocking on leaves. I did, however, like mixing up a Yggdrasil Dew every night, which takes about the same amount of time as a sabercat ride from Argonia to the Tree of Styx (which ALSO takes about the same amount of time as a full night), arriving just barely before dawn, and getting a new Leaf. (Technically, the ride was a bit shorter than mixing up a Dew or the length of a full night. But not by very much.) I then warped to Neos and hunted Gold Golems until night fell again.
"As the good archmage often admonishes me, I ought not to let my mind wander, as it's too small to go off by itself." -Danilo Thann