Often grown as a houseplant, Kalanchoe daigramontiana has a few great common names, including mother of thousands, alligator plant, and devil’s backbone. The ability of the species to rapidly grow many leaf-borne plantlets earned it the first common name. One of my own common names is “mother of two”, and I can’t imagine being able to produce thousands more!
Producing but two offspring has left me often feeling overcrowded and out-competed for resources, yet I have watched my own potted Kalanchoe daigramontiana effortlessly produce one set after another of miniature versions of itself (and as a single parent, at that). Despite this astronomical accomplishment, my houseplant seems to always look healthy and elegant. How does Kalanchoe daigremontiana do it? The Plants are the Strangest People blog has a humorous article that suggests this species has “made some kind of deal with the devil”. If you own one of these as a houseplant, or worse yet, you live in a semi-tropical area and have one growing as a weed in your yard, you may suspect this to be true.
There is an irony to the reproductive success of mother of thousands. Somewhere along its evolutionary path, it has lost the ability to reproduce sexually; a gene normally used in the creation of seeds (LEC) mutated and now can only produce nonviable seeds. However, when this gene is present in leaf tissue along with a gene regulating for organ development, the species instead has the ability to create little clones of itself from spurs located at the leaf margins (see: Evolution of asexual reproduction in leaves of the genus Kalanchoe by Garcês et al., and Zhong et al.’s article). As these little clonal plantlets grow, they develop swollen bases that store water and nutrients, even producing roots while still attached to the mother plant. Once the plantlets have six leaves and well-developed roots, they detach from their mother, fall, and begin to grow on their own. These plantlets are much hardier than the seedlings of any other species that I have attempted to grow. I have seen them survive for weeks on a tiled countertop. They also have no trouble taking hold in cracks along my windowsill. Unlike my own children, Kalanchoe daigremontiana‘s offspring wait patiently in the hope that they will somehow be rewarded with a meagre base of nutrients and water; when given so, they efficiently use these resources without complaint.
Mother of thousands is a powerhouse of asexual reproduction. Not only does it develop the above-described plantlets, it also frequently develops roots along its main stem. As mature plants lengthen, they tend to get tall and lanky. They then fall over, bringing lateral roots along the stem into contact with the soil, where they will take root. These qualities make Kalanchoe daigramontiana invasive in arid and frost-free zones, and, to some extent, even in the home. After learning the hard way, I now keep all of my other houseplants well away from my mother of thousands, after having had to laboriously pick hundreds of plantlets (or at least 30ish) out of the leaves and spines of my other cherished plants. And speaking again of motherhood, Kalanchoe diagramontiana‘s many offspring may hurt your few: all parts of this species are poisonous, and care should be taken that the little dropping plantlets are not found by curious toddlers.