According to both the minecraft wiki and all other sources I can find, tulips supposedly generate rarely in plains. However, after bonemealing thousands of blocks of grass, as well as travelling thousands of blocks across a plains biome, I have yet to see a single tulip.
MC-262097
Tulips Don't Generate in Plains
Resolved
Duplicate
0
BCNOFNeNaMg
(Unassigned)
Unconfirmed
(Unassigned)
1.19.4
Retrieved
Not all flowers that generate naturally in a biome will also appear when bonemealing grass in that biome.
The fact that tulips are currently much more rare in plains biomes is MC-238711, so I'll resolve this bug report as a duplicate.