Rare and Unusual Euphorbia Plants for Collectors

By Tyson Curtis in Partnership with Flora Grubb Gardens

There’s something in human nature that makes us want what we can’t have. I suppose this is why so many of us long for the rarest and most unusual plants, myself included.

My name is Tyson and anyone who knows me will tell you that I have an actual problem with collecting plants, now numbering in the hundreds? Thousands? Too many to count. So when I heard whispers around here at Flora Grubb Gardens about the “lost greenhouses of Bolinas,” I had to learn more.

The rumor was that Herman Schwartz, a collector of unusual plants, had become so obsessed with his plant collection that he’d built several greenhouses smack in the middle of one of the windiest, foggiest, dreariest climates in Northern California. When he ran out of what he could gather through friends and fellow collectors, he began to make pilgrimages to Africa, taking cuttings of the most unusual plants and bringing them home to cultivate. Schwartz lived into old age, supposedly building his collection to over 20,000 plants, until he passed away in 2008. In the years since, according to rumor, the plants had completely overtaken the greenhouses, unknowingly trapped in a failing biodome. To me it sounded more like an urban legend than a likelihood. Little did I know that I would eventually get to encounter the truth for myself!

My own obsession had started out with succulents, but quickly narrowed to a rare niche: the succulents we call caudiciforms. These “fat plants” are defined by the distinctive caudex, the swollen root or trunk that’s used for storing water. Caudiciforms grow in harsh climates, sculpting them into natural bonsai over time. (Familiar caudiciforms include Adenium obesum (Desert Rose) or Beaucarnea recurvata (Ponytail Palm).) For “fat plant” collectors there is one book that’s considered the holy grail of resources: Caudiciform and Pachycaul Succulents by Gordon D. Rowley. The problem is, there was only one edition published of this book, and the edition runs around $300—if you can find one. I spent years popping into every bookstore I passed, from Oregon to New York, on a hunt for the grail. Nothing. I only ever saw a copy once, at the home of a millionaire who knew nothing about plants and thought the pictures were pretty. Then one day I opened a birthday present from a very special person and there it was in my hands.

As I paged through my beloved holy grail, the urban legend about Schwartz’s greenhouses was floating around my mind, teasing me. Who knew what crazy species could be out there in Bolinas, growing year after year, awaiting rediscovery. During one such daydream I remembered an entry in Caudiciform and Pachycaul Succulents about greenhouses and collectors. It occurred to me that Rowley and Schwartz must have run in the same circles during the ‘70s and ‘80s, with such a small community of “plant dorks” around, and so I took down the grail and thumbed to the page I remembered. The photo was of a glistening greenhouse setup, brand new and without plants. A caption below read: 

“15.2 Modern glass houses, designed for maximum lighting, hygiene, aeration and easy maintenance are ideal for housing caudiciforms: they never had it so good! The glasshouse illustrated is a new wing of the Euphorbia reference Collection in Bolinas, California. ”

The rumors suddenly seemed both more legendary and highly likely to be true! 

It was Flora Grubb herself who verified the actual existence of the “Lost Greenhouses,” officially named the Euphorbia Reference Collection. Better yet, she had a connection who could get us in: Herman Schwartz’s son, David Schwartz, a landscape architect. He had maintained the greenhouses all those years, a daunting task by any measure, and he happily invited the FGG team out to see them. What’s more, he generously offered to let us take all the cuttings we wanted. When did we want to go? 

In the summer of 2017, our crew of plant dorks piled into a van and bubbled with excitement as we tracked the serpentine roads over Mount Tam and through dank redwood forests. It seemed an unlikely gateway to a collection of African desert plants. Down to the ocean, white-capped and unrelenting, and through green fields of grass rippling in the wind. Finally we found ourselves on a dirt road into the property. Right up to the last moment we withheld our optimism, afraid that the collection wouldn’t live up to our expectations. 

We pulled into a rounded driveway surrounded by half a dozen greenhouses, their white paint flaking off of bleached wood, some sagging, all tucked behind a massive succulent garden, itself overgrown and thriving. We had a hard time even making it into the greenhouses, immediately distracted by rare plants in the succulent garden. One of us would shout, “Look at this, has anyone seen this before!?”  And each of us in turn would respond, “I have no idea what that is.” The experience turned back time for each of us, restoring the naive wonder of a new hobbyist, when every turn leads to surprise and joy. We kept moving forward, heading inside, but then: “Wow! Check out these aloes!” And again: “No idea what that is!”

When we finally entered the Euphorbia Reference Collection, it was like stepping into a spacecraft that had crashed in a post-apocalyptic world. Here and there were essential patches where caretakers had admirably kept things going, maintaining life support systems and structural integrity. The light was dim and amber, the furry fiberglass roofing long past its shelf life, except for beams of light that angled through where branches had ravaged the ceiling. There were rooms upon rooms, and the first we entered had shelving covered in a disarray of brittle plastic pots scattered among potting soil. The eerie scene unnerved me; it was as if some unknown catastrophe had hit the capsule, leaving a feeling of lingering mystery. 

In some of the pots, still on their potting bench, tiny euphorbia grew, including a very rare Euphorbia cylindrifolia ssp. tubifera from Madagascar. I’d never seen one grown from a cutting: a forgotten experiment! In one corner the bloated alien green caudex of an Adenia sprouted from the ground, its thick vining arms intertwined and buckling the potting bench slats, wrapping around posts and up into the rafters, flowing across the ceiling like green smoke. I’d never seen anything like it. I realized in that moment that I was standing inside the photo from Rowley’s book, but instead of the pristine white benches and crystal clear fiberglass, I had entered a lost world. The paint was tinged with mildew and stained brown from years of repotting, some benches were crippled and some rotting. And yet, under the benches, extensive colonies of rare Euphorbia, such as nigra and viscosa, continued to thrive. Life had found a way.

We passed through another capsule of that spaceship and into a whole different environment, a steamy jungle of columnar euphorbia, fireworks of red flowers bursting all around us, a 9-foot bramble of competition, so thick it was hard to focus in on the details, but when we did we found countless wonders. Euphorbia decaryi was tucked deep in the bramble, living out its life happily sheltered by the brutal competition above. Medusoid euphorbia, with their wiggling arms like a tide pool starfish. Euphorbia horrida, ice blue and looking like a mounded aquamarine gem.

Through another portal and into a large room with a massive Beaucarnea recurvata (ponytail palm), as if a brontosaurus had slouched to rest after that age-old meteor impact. A little further down the path, an even more swollen Phytolacca dioica slumped in in its place, reminding me of a defeated ankylosaurus. I’d only ever seen this tree once before in person, in the Huntington Botanical Gardens collection, and it blew my mind.

In our wonder we almost forgot that we were true explorers, on a mission to collect samples, and so we dove into our work, careful to avoid the toxic sap and thorns of the many unusual plants we gathered. 

We collected countless cuttings from these rare and unusual euphorbias and other plants, and now we have the honor of cultivating them in our own greenhouses.

This is how the lost plants of Bolinas came into our stewardship. The cuttings we collected that day were sent to our master growers down at Grubb and Nadler Nurseries in the Rainbow Valley in Southern California. Researching the euphorbia species proved a great challenge, and for some plants we had to content ourselves simply with the selection ‘Bolinas.’ We are honored to continue the Schwartz family’s legacy by cultivating the exceptional plants that came from their collection.

After years of cultivation in our own state-of-the-art greenhouses, many of these rare plants are ready to come home with you and continue their lives in your care. If you like unusual plants, like we do, please come by and meet these inspiring survivors! We hope that collecting them can bring you a little bit of that sense of magic and wonder we discovered on our trip to the lost world in Bolinas.