This is a small Euphorbia Lactea (aka, White Ghost/Dragon Bones), fully rooted.
Euphorbia lactea ‘White Ghost’ is the most popular cultivar of Euphorbia lactea. It can grow extremely big (10 feet) tall and it is almost totally white, which lacks the chlorophyll-bearing tissues necessary to produce green stems.
This one has small hints of green.
The sharp-spined stems grow in candelabra form and have a stark beauty.