I've created some simple palms and bushes for the terrain menu.
The plugin adds two new entries to the terrain menu, which each include a randomizer as well as several single or grouped palms/bushes to choose directly. It basically works like the in-game trees in the same menu.
Please note: The preview image for both entries is the same as for the original trees. I guess this is due to the fact that there is just one standard preview for a randomizer in the game. I'm sorry for that. But at least you can distinguish the plugin by the provided texts.
The palms and bushes are probably best suited for maps with the sand texture but they also work reasonably well on the original green ground texture.
I would like to give a special thanks to CommanderABab, without whom I would not have been able to complete this plugin!
Have fun!
P.S.: The rocks in the picture below are no part of the plugin. They are original content of the game and can be found in the decoration menu.
P.P.S.: It would be nice, if Lobby added these rocks to the terrain menu as well. Please

UPDATE
I have added a new file (Palms_Bushes_terrain.mdk_813_NON_AUTO_BUILD.zip) with "auto build":false, which will prevent the palms and bushes from being built automatically alongside the ingame trees when you create a new city. Just replace the old folder with the new one!