Houseplants: the pencil cactus (Euphorbia tirucalli) is actually a succulent rather than a cactus. Grow it in a sunny window but take care to avoid any contact with the white stem latex.
Pencil Cactus—How to Grow Euphorbia tirucalli
Euphorbia Tirucalli. Pencil Cactus. This can survive almost any amount of abandonment. Sculptural in form, this succulent can be pruned to the will of its caretaker; but be careful, as its milky latex can irritate your skin and eyes.
Euphorbia tirucalli (also known as Firestick Plants, Indian Tree Spurge, Naked Lady, Pencil Tree, Sticks on Fire or Milk Bush) (note to self. Keep out of reach of children)
Euphorbia tirucalli (Fire Sticks, Sticks on Fire, Red Pencil Tree) Toxic to dogs & cats. Do not get this plants sap in your eyes.
Pencil Cactus Care, Indoors & In The Garden
Pencil Cactus- the new "it" houseplant | gardenista Loves to grow indoors and can get up to 6' tall