The 16-35mm lens is the standard workhorse of landscape photography, but it is far from the only lens you can use for the genre, and, in fact, you are probably doing yourself a disservice if you rely exclusively on those focal lengths. If you are new to the genre and wondering what makes for a good lens kit, check out this helpful video tutorial sure to put you on the right path.
Coming to you from Michael Shainblum, this fantastic video discusses the ideal lens kit for landscape photographers. I strongly agree with adding a superzoom or telephoto zoom lens to your kit. You might balk at the sharpness you will get from something like a 28-300mm lens, but such lenses have come a long way in recent years, and furthermore you will usually use them at the optimal apertures for sharpness. Furthermore, the weight and cost savings you get from such a lens make them extremely convenient and cost-efficient, and the focal length range will allow you to get far more varied images from each scene you encounter. Check out the video above for the full rundown from Shainblum.
And if you really want to dive into landscape photography, check out "Photographing The World 1: Landscape Photography and Post-Processing with Elia Locardi."
It's just a lense nothing more.