OH,....I really hate to be the bearer of bad news...but that flower is really a strawflower glued onto a very nice Euphorbia. I bought several nice small cactus plants from Walmart that had these bright papery flowers on them. I took them home and carefully pried them loose or at least got the majority of the flower petals off. In time, the glue was removed through growth of the plant and coaxing. I wish they wouldn't glue the flowers to the plants, they would sell on their own merits to those of us that love them as they are, not "doctored".
Now that I got that off my chest, I would repot the plant in the larger pot, and by all means try to remove that flower so that it doesn't damage a growing point on the plant, or leave it if you like, it will eventually degrade to a faded memory of itself.

Kathy

I think you understand that the flower is fake. At least I hope you do ;)

Yes, use the smaller clay pot. The larger one is too large for your Euphorbia ferox (or maybe enopla).

Using the right size pot will reduce the chance of over-watering. You could use the larger pot, but it will hold much more water than that plant needs, and the soil will remain wet much longer than the smaller one. Overwatering is the number one cause of premature succulent mortality. Water succulents only when the soil is dry. Plant in loose fast draining soil.

Remember:

Water retention is bad bad bad.

Practice benign neglect and you won't be sad.

(I think I'm done now, aren't you glad?)

"Impressive how they emerge from the spines! How natural..."

LOL, yes I agree fully, except I hate it when the color (from fading) ends up all over the plant, don't you? And oh the flower stem, it is such a tough clear thing, makes one think of, humm.... glue sticks. : )

Rose

One of the factors to consider when choosing a pot is "Is it too big?" For the plants I grow, aloes, too large a pot can lead to much slower growth above the soil. Below, the root system will be broad and well developed, but most I know would prefer growth going to the foliage. Also, some feel if you "stunt" a plant by placing it in a smaller container, it may flower earlier rather than later if in too large a pot.

I choose larger pots because I am a "lazy" gardener and don't like to repot often, I also am a neglectful gardener, so there is no chance of overwatering. I guess that's why my plants survive and grow...I don't baby them. :) Did I mention they also don't get fed regularly? I'm bad, I know.

Kathy

ps. I have killed my share of "never let the soil dry out, keep moist but not wet" plants. I do well with little water or bog condition plants.

I am wondering if your plant is pot bound & the smaller pot is too little. You will know when you pull it out. I would go with the larger pot or a pot between the two if it is root bound. I agree with the above posters, but I personally like for my roots to have some room so they have available nutrients & some cushion during high heat times.