This flower belongs to a very common plant from CA, AZ and southern NV deserts - Cylindropunta ramoissima.
It is rarely seen in cultivation, but doing well in my greenhouse. Flowers are small and of unusual copper color.
Cactus flower is technically speaking not a 'true' flower but a sprout, that is a stem. With opuntoides it often goes to the extreme. Flower buds at early stage are hard or impossible to distinguish from new clatoides growing, and developed flower or even fruit may continue its life as a stem.
With C.ramoissima flower buds look like stems for long time, and may be they are just that - stems, until at some magic moment plant turns them into buds?