This is a cactus, but an unusual one. You may be familiar with the Easter Cactus (Hatiora gaertneri) or Christmas Cactus (Schlumbergia) with their flattened stems and relatively large red flowers. Like that species, Dancing Bones grows on trees or rocks in the tropical rainforests of south-eastern Brazil.
In a tree, or on a rock, the plant finds itself separated from the more reliable water supply that most plants source through their roots, so being a succulent (with fleshy, water-storing stems) is as much of an advantage as it is out in the desert. Dancing Bones grows quite happily in a normal potting mix and, in this case, on an inside windowsill facing south.
With its distinctively shaped segments, you can see why it might be called Dancing Bones. Its other common name, Drunkard's Dream, is a reference to the plant sometimes looking like a string of bottles. The segments range from sausage to almost baseball club shaped.
Its botanical name is Hatiora salicornioides, although you sometimes see it referred to as Rhipsalis salicornioides (it has taken some time for the classification of these 'epiphytic' cacti to be resolved). The species epithet, salicornioides, refers to its resemblance to the common salt marsh plant, Salicornia (a chenopod).
Dancing Bones was introduced into cultivation in England in 1817, and made it out to the colonies by 1850 (it appears in the 1850 and 1857 catalogues from Camden Park in New South Wales).
These days there are five species of Hatiora, including the Easter Cactus. That species flowers in early spring in the Northern Hemisphere - around March or April - hence its name. Dancing Bones seems to have a similar flowering cycle, although perhaps starting a little earlier, with its flowers opening in August (i.e. February in the North; and in Europe I've seen reports of it flowering in January as well). Drying out may also stimulate flowering: in my case I water it once a week, but hold back a little in winter.
The flowers are small, about five millimetres long, and they look like...well, this. They open and shut each day, for a few days, although never seeming to fully open on my windowsill. Pretty enough close up, but not a show stopper.
The berries that follow are not much showier, being translucent with a reddish tip (leading to another common name, the Mistletoe Cactus). Sadly my plant didn't produce any fruit: the final flower, and possibility, dropping last week. Still, it is a curious plant, and it has some funny names.
Images: All from this plant growing on my work windowsill.