Blooms in Autumn. Can be lifted with the Power Bracelet.
Rock Mushrooms are objects featured in Oracle of Seasons. During the seasons of Winter, Spring, and Summer, Rock Mushrooms serve has objects that obstruct Link's progression. Link cannot lift or damage these rocks. In Autumn, these rock mushrooms will bloom into actual mushrooms. After Link has acquired the Power Bracelet from Snake's Remains, he will be able to lift these mushrooms.
The first part of Rock Mushrooms can be found at the southwest corner of Horon Village, and just beyond them, a Treasure Chest containing some Rupees can be found.
Rock Mushrooms block the entrance to the fifth dungeon in the game, Unicorn's Cave. After Link gains the ability to change the season to Autumn using his Rod of Seasons, Link will be able to lift the rock mushrooms and access the dungeon.
Rock Mushrooms during the Summer in Horon Village
Rock Mushrooms bloomed during the Autumn