Since my world was created before 1.7, I'm do not see and new plants or trees such as Acacia or Dark Oak trees. Unseen plants include Blue Orchids, Alliums, none of the colored Tulips, Sunflowers, Lilacs, Large Ferns, Rose Bushes, or Peonies.
MC-41360
New Plants Do Not Appear In Worlds Created before 1.7
Resolved
Works As Intended
0
Correct, you will not see these items in pre-generated terrain before 1.7 only new biomes.
The report you have submitted is working as intended, mechanics of the game may change between updates. Things such as biomes, redstone, villagers and animals, may not work the same in current versions.
We strongly recommend that you don’t run 1.7.x on an existing world if you don’t want to run into chunk border issues.
World structures such as Nether Fortresses do not transition to 1.7 from 1.6, but loading these areas (and standing in them) in the new pre-release 1.6.4 and then going to 1.7.x should fix this.
For more information see: Version History