A lot of lower light plants will adapt to higher light, especially if it's filtered (through the leaves of taller plants, curtains, etc.). But for really high light: Agave spp.: have spines; I couldn't find toxicity info. Aloe spp.: turn up on both toxic and non-toxic lists, so it's hard to tell. Aloe vera (barbadensis) does seem to be toxic, for sure: other species may not be. Araucaria bidwillii (monkey-puzzle tree), A. heterophylla (norfolk island pine): only if you can have high humidity and cool temperatures. Safe for cats, though. Beaucarnea recurvata (ponytail palm): at least one source reports this as being safe for cats. Begonia spp.: are safe for cats. some/most Bromeliaceae (bromeliads): generally safe for cats most/all Cactaceae (cactus): not toxic, but I wouldn't necessarily say "safe," either, considering the spines. Calathea (peacock plant), Ctenanthe, Maranta (prayer plant), Stromanthe spp.: safe for cats. Caryota mitis (fishtail palm), Chamaerops humilis (European fan palm), Chrysalidocarpus lutescens (areca palm), many other palms: most/all are safe for cats. Chlorophytum comosum (spider plant): safe for cats. Coffea arabica (coffee plant): needs humidity to do well; I couldn't find safety info. Coleus spp.: at least one source reports this as being safe for cats. Cordyline australis (cabbage palm), C. terminalis (ti plant): additional humidity is definitely a plus. Couldn't find toxicity info. Crassula spp. (jade plant, etc.): couldn't find toxicity info. Dizygotheca elegantissima (false aralia): needs humidity, bug-prone, generally difficult. At least one source reports safe for cats. Echeveria spp.: couldn't find toxicity info. Fatsia japonica: bug-prone. One source reports this as being safe for cats. Ferns: Lots of confusion. Boston and rabbit's-foot ferns seem to be safe. Other true ferns may or may not be: it's really, really hard to tell. Full sun may not be desirable. Fittonia spp. (nerve plant): at least one source reports this as being safe for cats. Need high humidity to do well. Haworthia spp.: one source reports these as being safe for cats. Hoya spp.: safe for cats. Kalanchoe spp. (mother of thousands, panda plant, flaming katy, etc.): at least one source reports these as being TOXIC to cats, but there's not a lot of information to go on. Musa spp. (bananas): generally considered cat-safe. Pandanus utilis (screw pine): sharp-edged leaves. Couldn't find toxicity info. Peperomia spp.: safe for cats. Pilea (aluminum plant): safe for cats. Plectranthus nummularis (swedish ivy): best without full sun; safe for cats. Sansevieria spp. (snake plant): on some safe lists, and also on some TOXIC lists. Probably not worth risking, but I'm skeptical about the toxicity claims. Schefflera actinophylla (umbrella tree): considered safe for cats. Schlumbergera / Zygocactus (holiday cacti): safe for cats. Sedum spp. (donkey's tail): one source reports this as being safe for cats. Tradescantia spp. / Zebrina spp. (wandering jew, purple heart): at least one source reports this as being safe for cats. Yucca spp.: couldn't find toxicity info, but I suspect safe. - - - - - - - - - - - - - - - - - - - - I haven't personally grown all of these, and you'd be advised to double check on the toxicity before committing yourself. Consider these more leads to follow up on than actual recommendations. Some to definitely avoid unless your cats already know to leave them alone: Euphorbiaceae (spurge family): cowboy cactus, pencil cactus, devil's backbone, african milk bush (Synadenium grantii), african milk tree (Euphorbia trigona), croton, candelabra cactus, snow on the mountain, poinsettia Araceae (arum family): split-leaf philodendron, pothos, dieffenbachia, chinese evergreen, peace lily, Homalomena spp., Anthurium spp., Philodendron spp., Alocasia spp. (elephant ear), Caladium spp. Hedera helix (English ivy) Ficus spp. (rubber plant, ficus tree, fiddle-leaf fig) I've seen Dracaenas listed as toxic too, but I'm not convinced that's right. I was acquainted with a cat once who liked to nibble pretty much anything, and would take small bites of a corn plant (D. fragrans) sometimes. Though she far and away preferred the spider plant (Chlorophytum comosum). Of course, now that I think about it, that cat spent a completely unreasonable amount of time throwing up, too. Strelitzias (bird of paradise) are said to be toxic to cats. Lilies, as a group, are very dangerous to plants: easter lily, stargazer lily, tiger lily

I saw this happen to dry hot sunny conditions. I don't think it's fungus however, I see no harm using ornamental spray on it as long as you don't over do it. Mine are starting to cork at the base now. It must be hard as wood, if not, it may be something else.

Cut until you're in obviously healthy tissue, making the last cut with a clean knife. Have a bucket of lukewarm water nearby and wear appropriate PPE. The water's for staunching the flow of latex, the PPE's to protect you from chemical burns. Cut a healthy segment and stick the dripping end into the water for a minute, then set aside on some newspaper to dry and stop flowing. Wait a week, then dab the ends in Rootone, wedge slightly into soil (one that's at least half-porous material) and prop up with rocks/pots/stakes, Put in a sunny location and don't water them. Mist the stems every few days. You'll likely see growth (and therefore roots underneath the soil) in two months. It'd be good if the atmosphere was warm (ideal would be a heat mat for the night).

No sand at all, Noah. 50% pumice and 50% sieved potting soil would be great (along with a larger pot, if you want all three kept together). Don't water for a few days after repotting. As with all Euphorbias, be careful that you don't get the sap on your skin and particularly into any mucous membranes.