Codex Anathema, vol. VIII: Rise of the Quori
The Khalni Heart is a magical flower that is an outgrowth of the soul of Zendikar.
The Khalni Stone is a powerful ancient mana refractor at the heart of Ora Ondor in Akoum that is feeding the “The Impossible Garden” Life Bloom. The plants are said contain the raw, wild magic of Zendikar and mutate the elves who live there. 4 The relation between the Khalni Stone on one continent and the Khalni Heart on the other is uncertain.
Led by visions, the Zendikari elf Nissa Revane traveled into the depths of the devastated continent of Bala Ged to find the Khalni Heart which apparently had grown a new bud there. Rumors said that it had come to revive the land after the onslaught by the Quori. Through it, Nissa rekindled her connection to the land — but she also ran afoul of the demon Ob Nixilis, who hoped to use the power of the Khalni Heart to reignite his power. Flush with the elemental power of the land, Nissa bested Ob Nixilis, removed the Khalni Heart to safety, and escaped.