A couple of days ago, the Sacramento Cactus and Succulent Society (SCSS) went on a field trip to the UC Davis Botanical Conservatory. I’ve been there many times before, but it’s been a while since my last visit and there were quite a few things I hadn’t seen before. That’s probably why I took so many photos — although I seem to take a lot of photos no matter what.
According to their website, “The UC Davis Botanical Conservatory is home to a diverse collection of over 4,000 plant species from around the world, providing a unique space for education, research, and conservation. Our greenhouse showcases rare and unusual plants from tropical rainforests, arid deserts, and carnivorous habitats, offering visitors a hands-on experience with plant adaptations and biodiversity.”
The Botanical Conservatory does a lot of outreach to UC Davis students (check out their webisodes here), but I continue to be surprised by how many regular Davis residents don’t even know it exists — and that includes gardeners.
Consider this post my humble effort to spread the word: The Botanical Conservatory is a very special destination for anybody even remotely interested in plants. Yes, they do have cacti and other succulents in their collections, but those are just a tiny part. There’s so much to see, including oddities you’re not going to find in many other botanical collections in the U.S. Read on to see what I mean.
Our first stop was the staff greenhouse. It’s primarily used for propagation, but it’s also home to their giant water lilies (Victoria amazonica). This Amazonian native is considered one of the most difficult plants to grow outside of its native habitat, but Ryan Booke, a third-year plant sciences major and student employee at the Botanical Conservatory, has managed to successfully cultivate it. This April 2026 article in The California Aggie, UC Davis’s student-run newspaper, has a lot more details if you’re interested.
At the Botanical Conservatory,
Victoria amazonica grows in two above-ground swimming pools. The setup looks a bit cobbled together, but it doesn’t matter, because it works. Ryan has definitely figured out all the variables (especially water temperature and pH). What you see in the photo below is one plant. The leaves feel very leathery, and they can carry a surprising amount of weight — you might have seen photos or videos of babies sitting on a leaf (
like this one).
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| The spines look far more fierce than they really are. They’re meant to protect the leaves against herbivorous fish and insects. |
For UC Davis students, Victoria amazonica is a great destination for a first date. What makes it even better is that off in the corner, not far from the water lily pool, is a plant that is even more rare. In fact, the Botanical Conservatory is the only place in the U.S. that displays it publicly.
Venomous. Do not open. Keep away. What could be more exciting!
Gympie-gympie sounds like a cute name — the first thing I thought of was a cute stuffed animal — but in reality, it’s something far more sinister. Dendrocnide moroides is a notoriously painful stinging shrub found in Australian rainforests. It’s covered in tiny, silica-based hairs that inject a potent neurotoxin which causes immediate, agonizing burning. People describe the sensation as being burned by acid and electrocuted simultaneously. Apparently, the pain is so extreme that even morphine may not fully relieve it. The sensation can last for weeks, or even months.
A quick Google search unearthed all kinds of stories, including an incident involving a man who used gimpie-gimpie leaves as toilet paper, not realizing what plant he was picking up. The pain was so bad that supposedly he shot himself.
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| Gympie-gympie seedlings |
Here’s a recent Instagram post from the
Botanical Conservatory:
Personally, when I see a sign that says “Do not touch,” the first thing I want to do is touch. Fortunately, the gympie-gympie is locked away safely inside a terrarium. Ryan said that whenever they need to handle the plant, they have to don a full biohazard suit.
After the gympie-gympie encounter, the rest of the propagation greenhouse seemed a bit anticlimactic. Not that the plants were dull. Quite the opposite. There are lots of wondrous things to see.
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| Rocks — or not? The rock-like plants are Pseudolithos. The genus name means “false stone;” it’s easy to see why. These succulent flowering plants are members of the dogbane family (Apocynaceae) native to Somalia, Yemen, and Oman. |
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| Pseudolithos cubiformis from northern Somalia, this one with immature flowers... |
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| ...and this one with open flowers |
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| If you want your own Pseudolithos, you can buy them at the upcoming Botanical Conservatory plant sale for $15 (details at the bottom of this post) |
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| These are Euphorbia obesa (aka baseball plant). It’s a dioecious species, i.e. plants are either male or female. |
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| The mesh bag is to prevent unintended cross-pollination with other euphorbia species nearby |
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| This is a Dorstenia, not sure which species, but the flowers are typical for the genus |
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| Dorstenias are in the mulberry family (Moraceae) |
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| Dendrosicyos socotranum, the cucumber tree from the island of Socotra off the coast of Yemen. The Botanical Conservatory is one of the few places (if not the only one) growing this rare plant in the U.S. |
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| You can buy your own for $50 |
Moving from the staff/propagation greenhouse to the succulent collection greenhouse:
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| Deuterocohnia brevifolia, a bromeliad from Argentina and Bolivia |
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| A desert rose (Adenium sp.) in full flower |
Moving on into the tropical greenhouse...
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| Spanish moss (Tillandsia usneoides) and Hindu rope (Hoya compacta) |
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| Staghorn fern (Platycerium sp.) |
Here it’s all about the foliage:
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| Variegated philodendron |
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| A super cool philodendron with elongated leaves |
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| Vriesea sp. |
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| Black-leaved begonia |
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| More begonias |
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| And even more begonias |
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| This begonia had fierce-looking (but harmless) spikes on its leaf stems |
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| Cryptanthus sp. (or hybrid) |
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| Cochliostema odoratissimum, an epiphyte from Central America, its leaves... |
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| ...and flowers |
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| Arabica coffee (Coffea arabica) |
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| Coffea arabica fruit, i.e. coffee cherries |
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| And another Do Not Touch sign, making me itch to touch the plant |
And finally, a few photos of the welwitschias at the Botanical Conservatory. Welwitschia mirabilis is one of the true oddities in the plant world. Native to Namibia in southwestern Africa, this botanical anomaly is often described as a “living fossil.” It can live for over 1,000 years (!!!), but it produces only two leaves that grow continuously from a woody base, eventually splitting into leathery, wind-shredded ribbons.
This gymnosperm, a relative of conifers, ginkgos, and cycads, thrives in one of Earth’s harshest environments by harvesting moisture from coastal fog. Its deep taproot (up to 10 ft. long) and unique physiology allow it to endure extreme aridity.
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| The Botanical Conservatory also has one of the few (maybe the only?) variegated welwitschias in the country |
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| It truly is a thing of beauty |
The Botanical Conservatory is the source for welwitschias in the U.S. They have been very successful at growing and propagating it. According to Ryan, our guide, they have the largest breeding stock in the country and produce 1000+ seeds a year. They sell two-year welwitschia seedlings for $150. If that seems expensive, bear in mind how rare Welwitschia mirabilis is.
I’m not tempted by welwitschia (been there, done that, failed miserably), but if you are, the Botanical Conservatory will have a plant sale this Saturday, April 25, starting at 9 am.
They will sell welwitschias (of course), but also lots of other interesting plants. Check out
this Instagram story for a teaser:
The plant sale will be in the parking lot behind the Botanical Conservatory greenhouses on
Kleiber Hall Drive. Arrive well before 9 am for the best selection.
© Gerhard Bock, 2026. All rights reserved. To receive all new posts by email, please subscribe here.
So many cool plants. I need to visit again. It’s been over 10 years.
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