Hollow Trees | Magic: The Gathering
Formats Hollow Trees is Legal in
Official Oracle Text for Hollow Trees
You may choose not to untap Hollow Trees during your untap step.
At the beginning of your upkeep, if Hollow Trees is tapped, put a storage counter on it.
, Remove any number of storage counters from Hollow Trees: Add to your mana pool for each storage counter removed this way.
Official Rulings for Hollow Trees
10/4/2004 : This enters the battlefield tapped even if a continuous effect immediately changes it to something else.
10/4/2004 : If the land is tapped by some external effect, no counters are removed from it.
10/4/2004 : Counters are not lost if the land is changed to another land type. They wait around for the land to change back.
10/4/2004 : Whether or not it is tapped is checked at the beginning of upkeep. If it is not tapped, the ability does not trigger. It also checks during resolution and you only get a counter if it is still tapped then.