Hairy cactus or spun-sugar dessert?

Let's play a game I call "hairy cactus or spun-sugar dessert?"

Is this a hairy cactus? Or a spun-sugar dessert?

PHOTOS: Jennifer Sandlin

How about this one?

In case you had trouble guessing correctly, here are some resources to help you learn more about one variety of hairy cactus, the Cephalocereus Senilis—also known as the "Old Man Cactus," for obvious reasons. First, the North Carolina State University Extension Gardener website provides this handy overview:

Old Man Cactus is a tall, columnar succulent in the cactus family with spines that form fine white hairs reminiscent of an old man.  It is native to Northeastern Mexico but becoming more challenging to find in its natural habitat, but widespread propagation and popularity in cultivation may reduce the demand on wild populations. Old Man Cactus has clusters of stems that may grow to16 to 50 feet tall. However, the most striking feature is the shaggy coat of long, white hairs, hence the common name old man cactus. The coat is particularly striking on the young cactus, but, as the plant ages, the stem loses its covering. The hairs are modified spines and serve to protect the plant from frost and sun by reflecting the rays of the sun and insulating the cactus from heat and cold.  The hairs are only the radial spines of the cactus; beneath them are sharp yellow central spines. The solitary, nocturnal flowers are red, yellow, or white, though the plant may not flower for 10 or 20 years.  

I also enjoyed watching this short video by Brainy Gardener—it's full of images of the curious plants, and provides lots of tips about how grow and care for them.

I hope these resources help you avoid eating a hairy cactus. And, for the record, that spun-sugar dessert was divine—it was from Rick's Place in Kensington, Melbourne, Australia.