I happened to find a Euphorbia in early October, 2008 and thought I would just try one as a house plant. I did not pay any attention to the plastic label that said "Diamond Frost" and "Annual Euphorbia" or "AWARD WINNER", which I threw away. I remember that it came from PW (Proven Winners).
I was told that it would keep flowering and flowering. The plant was kept in its original small container, placed in my kitchen and exposed to indirect light.
It continued to flower for about 8 weeks then gradually slowed down and stopped flowering altogether. Up to that point I trimmed down the tiny branches and removed all the dead flowers; then I decided to let it grow in height, rather unevenly and moved it to the living room to get direct, partial sun light. It requires regularly watering, but appears to tolerate drought during my frequent absences.
I watched it grow and form new buds. The delicate flowers and tiny petals look remarkably beautiful in the close-up picture I took this morning.
This "Diamond Frost" is supposed to be a dwarf cultivar of "Snow Flakes" Euphorbia, about 12 inches in height. Mine has already exceeded 18 inches and there's no sign of slowing down.
I hope to plant it outdoors in the spring or early summer.
I could not believe how much I've learned about Euphorbia just this morning.
According to the Wikipedia
... "Euphorbia is a genus of plants belonging to the family Euphorbiaceae, consisting of about 2160 species. Euphorbia is one of the most diverse genera in the plant kingdom. Members of the family and genus are sometimes referred to as Spurges.
The common name "spurge" derives from the Middle English/Old French espurge ("to purge"), due to the use of the plant's sap as a purgative.
The botanical name Euphorbia derives from Euphorbus, the Greek physician of king Juba II of Numidia (52-50 BC - 23 AD). He is reported to have used a certain plant as a herbal remedy. Carolus Linnaeus assigned the name Euphorbia to the entire genus in the physician's honor."
So - live and learn.
I have also learned that Poinsettia belongs to the genus Euphorbia.
E. pulcherrima, a native plant of Mexico got its name from Joel Robert Pionsett, the first United States Ambassador to Mexico, who introduced the plant into the US in 1828.
Incidentally my Euphorbia pulcherrima, aka Poinsettia, is still as pretty today as it was in early December.