Whitelist scenarios to be tested from terrain.py

I have a bunch of features tested using Lettuce. I have a terrain.py file where I set up my webdriver. Right now the webdriver is only limited to Chrome and everything works fine. I run: lettuce and it runs all the scenarios.

Now I have to add tests for iOS and Android. Some scenarios are the same for all the three platforms iOS, Android and Web (I'm using appium), so I want to reuse them. So my idea is to be able to config a list of scenarios that I want to run in the terrain.py and have something like an array of scenarios to run for each platform so I can do something like:

lettuce ios

I grab in the terrain.py the "ios" param and configure the webdriver to use and which scenarios to run. Is this possible?