Octopus agave bulbils – thousands of them

The November 2023 meeting of the Sacramento Cactus and Succulent Society (SCSS) was all about making succulent wreaths. Members brought in a large variety of succulent cuttings, mostly things like crassulas, aeoniums, as well as echeverias, graptopetalums, sedums, and hybrids thereof. However, my eyes immediately went to this:

Somebody brought the flower stalk of an octopus agave (Agave vilmoriniana) laden with bulbils!

Almost all agave species are monocarpic, i.e., they flower once and then die. To reproduce, they employ various strategies. This includes making offsets, setting seeds, or producing bulbils – plantlets emerging on the flower stalk. Pollinated flowers can turn into seeds or bulbils; sometimes you find some of each on the same inflorescence.

A few agave species produce bulbils as a matter of course, others do so only when the inflorescence becomes damaged. Genetically, bulbils are 100% identical to the mother plant. In reproductive (and practical) terms, they’re a much faster way to grow the next generation than seeds.

Back to Agave vilmoriniana. It has arching and undulating leaves that bring to mind the tentacles of an octopus, hence the common name. Some specimens are more octopus-like than others:

Agave vilmoriniana at Moorten Botanical Garden in Palm Springs

Some less so:

Agave vilmoriniana at the Huntington

This summer, nine A. vilmoriniana planted in the same bed were flowering on the UC Davis campus:

Agave vilmoriniana in full flower in late May (photo by Heather Bock)

Now, six months later, the flower stalks are heavy with bulbils:

The number of bulbils in these photos is upwards of 10,000. That’s potentially 10,000+ new octopus agaves! I have no idea if any of these will be harvested. If so, I bet a few will end up in the plant sales at the UC Davis Arboretum Teaching Nursery.

According to this 1996 article in the American Journal of Botany, each A. vilmoriniana can produce upwards of 2,000 bulbils. The bulbils typically remain on the flower stalk until the second year even after the leaves of the mother plant have died off: “Second-year, attached bulbils are healthy-looking, even after leaves of the parent plant have senesced, since maternal roots continue to absorb rain water.” Once detached (or “abscised,” as the botanists say), bulbils produce water-absorbing roots within two days.

I don’t know what percentage of bulbils survive in the wild after they fall off; it all depends on whether they land on soil that has sufficient moisture to promote rooting. In cultivation, virtually all except the tiniest ones turn into viable plants. Once you’ve had an A. vilmoriniana flower, you’ll never need to buy another one – and neither do your friends, your neighborhood, and potentially your entire town. The sheer number of bulbils may even be too much for a botanical garden. A few years ago, the UC Berkeley Botanical Garden was giving away A. vilmoriniana bulbils:

As for the A. vilmoriniana bulbils that showed up at the SCSS meeting, I have no idea if they were all taken (doubtful, there were just too many) or what ultimately happened to them because I had to leave early. I wonder if any of them made it into a succulent wreath or two?

© Gerhard Bock, 2023. All rights reserved. To receive all new posts by email, please subscribe here.