Environs++

Looking for the Fabric 1.20.4 port? find it here.
Environs++ adds a modest amount of biomes to the Minecraft world, all of which stay true to the vanilla style. Some of the included biomes were heavily inspired by old, removed Biomes O' Plenty and ExtraBiomesXL biomes.

Versions before 1.0-pre2 do not work on servers, and versions after 1.4 are not compatible with older releases due to some major changes.

Biome List:

1.0: 

Dry Oak Forest (Variant: Mutated)

Emerald Cliffs

Icy Hills

Pine Taiga (Variant: Mutated)

Silk Wetland

Stone Basin

Tall Oak Forest (Variant: Mutated)

Tall Oak Wetland

Wasteland Spikes (Variant: Eroded)

1.1:

Cold Pine Taiga (Variant: Mutated)

Sandstone Ranges

Roofed Swamp

Stone Hills (Sub-biome of stone basin)

1.2:

Mushroom Rainforest

Overgrown Plains

Kakadu

End Forest (Variant: Mutated)

1.4:

Canyon

Lush Forest

Trees and Mushrooms:

Pine: A tall, spruce-like tree which generates in extreme hills+, extreme hills m and pine taiga biomes.

Cypress: A swamp-like tree, generating in swampland, swampland m, sludgepit, silk wetland and tall oak forest biomes.

Eucalyptus: An acacia-like tree, generating in savanna, plains and sandstone ranges biomes.

Frozen: A large, white spruce-like tree exclusive to the relatively rare icy hills biomes.

End: A set of four different trees exclusive to the end forest biome. The saplings only grow into shrubs, making these trees hard to farm.

Purple Mushroom: A taller version of brown mushrooms.

Cyan Mushroom: A cyan version of red mushrooms. 

Modpacks: Feel free to use any version of this mod in a modpack. I recommend running the mod with Climatic Biomes, as it makes for some picturesque landscapes with these biomes!