Upon putting down the foundations for a cattle ranch, in other words, issuing a command to build it, it spawns a bunch of plants in explored areas where you don’t have vision at the time from the either the saharan or the gobi desert biome to the map, regardless of the biome. Having vision, like moving a scout there removed the plant permanently. The plants are visible for both players, which means your opponent is aware that you are building ranches without scouting it. Some of the plants stay there after some further testing
You need to have the map concealed, explore it manually, and have to age up from dark age to feudal to trigger the bug. Starting the game from feudal or with an explored didn’t work for me when i tried to reproduce it. Feudal landmark choice has no effect on it.
You can see 3 extra yellow grass/brush that wasn’t there on the first picture
It’s not just Malians and it’s not related to cattle. It seems to be a general bug that was introduced in the last patch. I’ve created another topic showing the exact same grass patch glitches. I still haven’t found a clear pattern, but it triggers when aging up. What GPU do you have?