[John J]

Today I have included a cactus, Tephrocactus articulatus var papyracanthus. Very easy to grow as pieces break away and root readily.
The third photo is, I believe, T. articulatus var inermis but there appears to be such a wide variety that I'm willing to be corrected.

[John J]

We have 4 different Thunbergia.
Thunbergia alata and T. alata 'Arizona Dark Red' (unfortunately not in flower).
T. erecta.
T. grandiflora.

[John J]

Tradescantia make useful ground cover. We have a few varieties including, T. pallida 'Purpurea', T. sillamontana, and T. spathacea among them.

[John J]

Tulbaghia violacea looks good when planted en-masse but can emit a strong smell of onions.