I have a plant which looks like a succulent or could also be a cactus. It grows long tendrils which climb onto any structure out of a large bulb. Tine white blossom appear in the spring and drop as little bulb into neighbouring pots where they then grow.
Thank you for contacting the Toronto Master Gardeners.
The plant in question appears to be a beautiful specimen of Bowiea volubilis commonly referred to as the “Climbing Onion”.
These bulbs, like onion and tulip bulbs are comprised of tightly clustered modified leaves which serve as reserves of nutrients and moisture. Depending upon growing conditions, the bulbs may be uniformly pale green, or may be covered or partially covered with the dried remnants of outer leaves much like an onion skin.
As you’ve already noticed, these plants produce large vines (can grow upward of 15′) which are actually the plant’s inflorescence. The plant produces many dozens to hundreds of tiny star shaped flowers which will readily set seed and grow into new seedlings.
I am including a few links on the proper care of this unusual plant: