As the dog days of summer settle in over our Sonoran Desert oasis, the queens are beginning to wake…
Continue readingBloom Watch #1 | Tracking the Bloom
Bloom Night 2024
Saturday afternoon was filled with anticipation. At noon when Chris carefully checked the buds, they were soft, signaling that they were ready to go!
The evening that followed was a celebration fit for desert royalty. As the glowing sunset faded into the night sky, the air was filled once again with native flute music and a cheerful murmur. Curiosity, excitement, and a wistful peace permeated Tohono Chul.
From the Pavillion, Garden’s Manager Jack Dash gave a presentation where he shared his extensive knowledge of the Queen of the Night. With fresh insight, visitors then ventured out to see the Queen for themselves.
The soft glow of lights decorated the park and lit the pathways through the dark labyrinth of Desert View Trail. Our dedicated docents guided visitors as they marveled at the elegant white blossoms.
Observant guests were greeted by kangaroo rats, desert millipedes, and nighthawks. Some adventurers searched for scorpions with a UV light. We were excited to welcome an enthusiastic film student from the University of Arizona who came out to film eventgoers experiencing the blossoms for a documentary. The trail was bustling with people eager to see this cryptic desert plant come alive.
Not only was the desert open for viewing for members, but Bloom Night coincided with “Chillin’ at the Chul’, with refreshments and music creating a fun community space. At the Overlook, the Queen’s Court was also in full bloom for the public to enjoy.
My hope is that we will remember a feeling—that the desert is special and holds one-of-a-kind living beings like the Queen of the Night.
Check out these stunning photos of the Queen from Bloom Night!
Bloom Watch is written by Tracey Till, Propagation Coordinator
Until next year…
Click here to sign up for Bloom Watch emails.
Be sure to select “Bloom Watch” on the dropdown menu.
Bloom Watch #3 | A Royal Growth Spurt
Monsoon Magic
Last Friday morning as Chris Kibler, Senior Gardener here at Tohono Chul, made his rounds on the Desert View Trail, he noticed that the buds on the Queens were still small and tightly closed; but a lot can change in a few days. Bloom Night is approaching much faster than we originally predicted!
The summer solstice began blanketed in a dusty haze. A nebulous veil covered the mountains and a strong wind swept the city. Sand was carried over hundreds of miles high in the sky across the Southwest from New Mexico; a cloud of seeds.
By Friday afternoon, the weather was shifting. The dry heat, a trademark of June in Tucson, began to moisten. Clouds were forming to the east which soon spread over the horizon. “We’re crossing our fingers that we get some rain,” said Chris. That very next afternoon, the familiar, earthy smell of petrichor filled the air. Puffy cumulonimbus clouds formed over the Catalinas. The sky opened up and delivered the first Monsoon of the season, quenching the desert’s thirst and feeding the Queens.
I’m sure you have noticed the increased humidity this week. Doors are swelling. You can cut the air with a knife. This consistent humidity has done wonders for plant life throughout the garden and surrounding desert. It’s almost as if you can see things growing in real time.
Due to this rapid growth spurt, we anticipate Bloom Night to occur sooner than expected. That’s right — the Queen is coming! We predict that the buds will grace us with a royal show either late this week or early next week. Last year, they chose July 23rd as their day. Which day will our resident monarchs choose this year? Will it be this weekend? Maybe. All we can do in the meantime is measure, observe, and wait.
The Queen’s Court
Meanwhile, at the Overlook, Chris discovered that our Peniocereus collection, known as the Queen’s Court, has sprouted 79 buds!
The Queen’s Court collection is a great example of the remarkable diversity found within the Peniocereus genus. These unique plants are native to the Southwest US and Mexico, flourishing in varied and distinctive habitats; from the creosote flats and gravelly slopes of the Sonoran and Chihuahuan deserts to the dry tropical forests of Western and Southern Mexico. For example, Peniocereus serpentinus can be commonly found growing in the understory of mesquite woodlands. At the same time, the Peniocereus marianus has been spotted sprouting from a sheer basalt cliff on the Sinaloan coast.
Buds in the Queen’s Court have begun to bloom sporadically, much to the delight of local pollinators. Bats, birds, and insects, especially certain moths, eagerly await their late-night snack. Since the Queen of the Night blooms only once a year, pollination is critical to its survival.
Pollination is the reproductive process of plants where pollen is transferred from one flower to another, enabling seed and fruit production and ensuring the next generation of plants. The Peniocereus greggii relies primarily on nocturnal pollinators, particularly sphinx moths (Sphingidae), for this essential process.
The Queen of the Night’s flowering behavior, scent, and structure are finely tuned to attract nocturnal pollinators. Its large, bright, tubular flowers are typical of plants pollinated by moths. The narrow shape facilitates easy access, allowing them to hover and reach deep into the flower with their proboscis, a straw-like mouthpart used for feeding.
Soon, the desert will be alive with the fluttering of moths and the sweet scent of blooming Queens.
Bloom Watch is written by Tracey Till, Propagation Coordinator
The Queen is Coming…
Due to rapid growth from recent rain and increased humidity, we predict Bloom Night to occur sometime within the next 7 days, potentially as soon as this weekend.
Sign up for Bloom Watch emails here.
Be sure to select “Bloom Watch” on the dropdown menu.
Members Only
This year, Bloom Night is an exclusive members-only event. Your support helps preserve the Desert View Trail and our Peniocereus greggii collection while we work to ensure proper pollination of these special plants.
Don’t miss out—become a member today and unlock a year of perks and benefits at Tohono Chul, including early access to plant sales, discounts, free daily admission, reciprocal admissions at other public gardens, and much more.
Predictions and estimates for Bloom Night are subject to change based on various factors such as weather conditions, growth patterns, and environmental influences.
Bloom Watch #2 | Beneath the Surface
Tohono Chul Gardeners Chris Kibler and Shauna Smith, along with dedicated volunteer Tammy, have been diligently watching over the Queens and measuring their progress.
Shauna and Chris recorded measurements of the growth of the buds for our records. “Most are at 40 mm, with a few near 60mm. With the onset of this heat they’ve slowed down.” said Chris, Senior Gardener at Tohono Chul. According to the Gardeners, Bloom Night could be anywhere between 2-4 weeks out. But as we all know, Mother Nature works on her own timeline.
I ventured out to the Desert View Trail early Tuesday morning to see the Queens for myself and hear what the trail has to say…
Larrea sparkle in the morning sun, as if covered in dew. Seeds waiting for the winds of change, the monsoon.
A gossamer seed released like a puff of smoke, floats by.
Spiderwebs glisten between branches, the invisible is visible.
Every tree is a tree house for the beetles and bees. You can see the small oval holes like windows.
A wasp, brown and red, hovers over a Queen of the Night.
Flowerbuds! They decorate the plant like little black and white flames. Star-shaped spines cling to the trunk of their nursery tree, an acacia.
Amongst the wild trees and grass the soil is covered in white and orange stones.
Gneiss stones freckled with garnets slowly worn away into sand by streams of rainwater and wind.
Many small footprints appear in the dusty, well-worn path. Hoof, paw, and claw. An occasional sneaker print from a Tucsonan.
My walk makes me wonder, what is this gravelly soil made of anyway? Why does the Peniocereus greggii grow here and not everywhere?
Heading back to civilization and leaving the peaceful morning vista, I’m sitting at my desk. I decided to let my curiosity stray from the winding paths of the Desert View Trail and onto the winding paths of a Google search. I came upon the Web Soil Survey website (provided by the USDA) and looked up the Desert View Trail’s location on their interactive soil map. Now, soil science is a foreign language to me, so I must read slowly to understand… “Alluvium derived from schist and/or alluvium derived from gneiss… along with other granitic and some volcanic and sedimentary rock”.
Okay, let’s break this down!
Alluvium is made of sand, gravel, silt, and clay deposited by flowing water. According to their website, The Desert View Trail and much of the surrounding area were likely formed during the Ice Age when mountain glaciers melted and produced lakes and rivers that deposited these sediments. Over time, calcium carbonate was also formed as slightly acidic rainwater trickled through the layers. The expanse of time; the natural forces of water, wind, and sun that shaped the landscape is awe-inspiring!
It seems the Queen of the Night is well adapted to the sandy, silty, gravelly soil. Perhaps adequate moisture and drainage are all that is necessary to allow the large tuberous root to grow and to prevent rotting.
Earlier, botanist and Tohono Chul Gardens Manager, Jack Dash, brought up the question to me of whether the baby Queens we are growing in the nursery could benefit from symbiotic microbes native to the desert soil.
Perhaps more is going on than can be easily seen. What else could be going on beneath the surface? Soil is not only a collection of tiny non-living rocks but a thriving and bustling community and ecosystem. It’s filled with active plant roots, algae, fungus, bacteria, and small invertebrates.
Many people know about the miraculous mycorrhizal (fungi that have a symbiotic relationship with the roots of many plants) that colonize tree roots and enable them to absorb more nutrients from the soil. It turns out that cactus also facilitate partnerships with fungi friends! According to the book Cactus Biology and Uses, root samples of different Sonoran cactus species were anywhere from 10% to 70% colonized by mycorrhizal fungi.
However, I have yet to dig up an article specific to Peniocereus greggii mycorrhizae. What might be happening beneath the soil of our Queens? For now, it remains a mystery to me.
The Queen knows where to grow. The Queen knows when to bloom. When she is ready.
Bloom Watch is written by Tracey Till, Propagation Coordinator
We are estimating about 2 to 4 weeks away from the big night!
Stay tuned for updates.
Click here to sign up for Bloom Watch emails.
Be sure to select “Bloom Watch” on the dropdown menu.
Members Only
This year, Bloom Night is an exclusive members-only event. Your support helps preserve the Desert View Trail and our Peniocereus greggii collection while we work to ensure proper pollination of these special plants.
Don’t miss out—become a member today and unlock a year of perks and benefits at Tohono Chul, including early access to plant sales, discounts, free daily admission, reciprocal admissions at other public gardens, and much more.
Predictions and estimates for Bloom Night are subject to change based on various factors such as weather conditions, growth patterns, and environmental influences.
Bloom Night Recap | The Queen’s Monsoon Magic
Last Sunday was an eventful one. Chris says that early that morning, the buds were still closed tight, but by afternoon some were already showing the white of their petals!
Around 6 pm we could see an opaque storm cloaking the northwest from Tucson’s East side. Filled with excitement and cautious optimism we made our way to Tohono Chul. Beautiful cascades of rain fell in front of the sunset. A dramatic backdrop of pink cotton candy clouds and lightning set the stage.
The brief downpours cooled the air and filled it with the scent of creosote leaves. The Queen’s blossoms were timid and we waited expectantly for them to open. Native flute music echoed as we crowded around the blooms. Nature does not hurry for anyone.
The monsoon gifted us with some much-needed rain and brought life and vibrancy to the Desert View Trail. Tarantulas, tarantula hawks, sphynx moths, night hawks, and other critters were out and about. Spadefoot toads sang. Guests poured into the gift shops and took refuge under the ramadas. The exhibit house was a welcome escape from the rain and gave us a moment to experience an artistic interpretation of the Queen and the Sonoran Desert.
It was a lovely garden party for the Queen, filled with music, untamed beauty, and community.
At 6 am the next morning the blossoms were still open and the fans of the peniocereus greggii filled the parking lot. A fervor of photographers took a morning stroll to see the ephemeral flowers.
The very next evening we had the few last remaining buds open. We hope that these uninterrupted inflorescences will show a good pollination rate. The gardeners carefully covered them in mesh bags to protect the developing fruits. We shall see!
Thank you to everyone who came out and braved the rain. For all the volunteers and staff who made it possible. To those who waited patiently for a glimmer of beauty. Happy Monsoon!
Until next year.
Tracey Till, Propagation Associate
Bloom Watch #9
Bloom Night is Coming…
Movement! As Chris suspected, the Queen’s buds are growing after the rain we had on July 17.
The Queen’s are growing 20 mm a day now, which puts us a few days away from Bloom Night! The largest of the floral branches has reached 120mm, with the smaller ones close behind at 90-100 mm. We are watching closely, but as we know, the Queen is in charge. We won’t know exactly when the Queen decides to bloom until the day of, but we suspect that it’s very soon.
Monsoon time is here! According to a dedicated volunteer, the Penstemon Garden’s rain gauge had almost 2 inches of rain! Rain events bring more than just water- there is a change in temperature, humidity, and soil environment.
Soil biocrust becomes more visible as the algae and cyanobacteria grow. The desert plants respond, such as the typically leafless cholla putting out tiny true leaves next to their spines. Perhaps some of the Queen’s cactus seeds that were dispersed last fall by animals will wake up, carried to just the right spot under the shade of a mesquite, or a nook amongst the creosote, they will start to sprout. It’s a magical time to be in the desert.
Watch for our next post, as Bloom Night is imminent now!
By Tracey Till, Propagation Associate
Don’t miss the big night! Sign up for Bloom Watch emails here.
Be sure you select “Bloom Watch” on the dropdown menu!
Bloom Watch #8
An Extrafloral Moment
As of Tuesday morning, the buds are stalled between 40 and 55 mm. Thanks to the rainstorm that came through last night we expect movement in the next few days. They are taking their time, waiting for the perfect time to bloom. Let’s remember to take things slow in this hot weather too!
In the meantime, let’s talk about cactus biology!
One day when I was visiting the Queen’s Court at the Overlook, I noticed something different. Tiny white spheres dotting some of the flowering branches of the Peniocereus. At first, I was concerned it might be honeydew from sap-sucking insect pests! However, I’d read about extrafloral nectaries on barrel cacti and held out hope that I might be observing them on the queens.
Extrafloral nectaries are glands that produce a sugary substance on a plant that exists separately from flowers.
Here is some cactus anatomy for context.
Evolution can take one facet of an organism that is used for a specific function and mold it like a piece of clay over time to fit a different function. Cacti are unique from other succulents by having what are called areoles. These evolved from normal lateral shoots that at one time had separate buds spaced out along the stem.
They became compact areas where spines, leaves, branches, and flowers all emerge. From a distance, they may look like an asterisk * thanks to the spines. In the case of our Queens, unique areoles occur on the flowering branches of our Peniocereus oaxacensis and Peniocereus rosei and this is where the extrafloral nectaries occur.
We’ve established that extrafloral nectaries (EFN’s) are specialized structures that produce nectar without a flower. They occur in many plants and not just cacti. If you see a tiny bump on a plant exuding a droplet of dew, it may be an EFN. Evolution gets creative when it comes to cacti; in particular, they can have different types of EFN’s. For example, Ferocactus emoryi, one of our native barrel cactus, has small round modified spines that look like little bumps. Harrisia pomanensis, also known as moon cactus, secretes nectar from totally normal-looking spines. Some also have specialized stem tissue like Pachycereus gatesii, a cousin of the senita. And still, others secrete nectar from tiny scale-like leaves at the base of the areole, as do our Peniocereus in the spotlight. (source)
Why make nectar without a flower? For what purpose does the nectar serve, if not for attracting pollinators? Let’s remember that plants are in symbiosis with many insects that live on, under, and inside them. For many plants, an important insect friend is the ant. Ants will protect a food source from other herbivorous insects. In the case of cacti, ants can take care of any bugs that get past the spines and would otherwise like to eat a juicy cactus.
The closer you look the more you will realize what an intricate ecosystem the Sonoran Desert truly is.
By Tracey Till, Propagation Associate
Don’t miss the big night! Sign up for Bloom Watch emails here.
Be sure you select “Bloom Watch” on the dropdown menu!
Bloom Watch #7
Another rogue player …
“It looks like we have another rogue cactus on our hands!” said Chris on Monday morning.
Queen of the Night #379 is at the head of the pack with two buds measuring 110mm and on track to bloom this week. The rest of the regal monarchs are still between 40mm-60mm.
“With the increase in humidity this week, (40% this morning!) they may pick up the pace. I’ll definitely keep you all posted.” he says.
“The Queen’s Court at the Overlook has several cacti ready to bloom. One was blooming Friday night! Check them out if you’re brave enough to go outside!”
A Botany Lesson
Speaking of the Queen’s Court (the row of potted cacti positioned at The Overlook here at Tohono Chul), one of the courtiers, Peniocereus striatus, illustrates a fascinating example of convergent evolution in the plant kingdom. Convergent evolution is the process of distantly related organisms evolving similar traits in order to adapt to similar situations. Introducing, Euphorbia cryptospinosa, native to the landscapes of Ethiopia, Somalia, and Kenya.
This completely unrelated plant from the opposite side of the planet has been shaped by it’s own climate to look much like our Peniocereus striatus. Both have tuberous roots, with slender cylindrical stems that are camoflagued amongst the shrubs where they both grow in sandy, gravely soil. In addition to being succulent, both have developed an ingenious way of preventing extra water loss during drought.
Stomata are unique to plants and are the specialized groups of cells that open and close to allow for gas exchange of CO2, oxygen, and water vapor, through the epidermis of a plant. In our courtier and our friend the Euphorbia cryptospinosa, the stomata are restricted to narrow furrows that run vertically along the stems. When they have acquired sufficient moisture, these stems are plump and the stomata are more exposed to the air to enable gas exchange, but still shielded from the wind.
When the plant stems lose water, the furrows are sucked in from this water loss and they begin to close up like an accordion. By enclosing their stomata this way, they preserve their thin stems from shriveling up, even in very dry habitats. By studying comparative anatomy in this way, we can learn a lot about how plants work. Thanks to the University of Arizona Herbarium for providing this research for free so we can all level up our botany!
By Tracey Till, Propagation Associate
Don’t miss the big night! Sign up for Bloom Watch emails here.
Be sure you select “Bloom Watch” on the dropdown menu!
Bloom Watch #6
Blooming Secrets
Our persistent Garden Manager, Chris Kibler, says the Queen’s buds have grown very little over the past week, with the biggest just a tad over 50 mm. However, he’s noticed changes that hint at something to come.
The sepals are starting to turn reddish in color and the white hair on the buds is more prominent. According to our botanical records, towards the end of a stall period in bud growth, the color and shape of the buds begin to change. This, along with weather predictions of an increased chance of rain and humidity next week, has lead Chris to anticipate a growth spurt soon! We could have bloom night as soon as sometime in the following 10 days! He is visiting the Queen’s every morning now. “They’re coming soon- I promise!!!” he says.
I’ve had the privilege to look at our Bloom Night records that catalog the many attributes of the collection, including the condition, phenology, size, and care of the Queen, which were diligently written by stewards of Tohono Chul over the past 30 years. Notes from the past that were handwritten with care. This got me thinking. Who is this plant, not just to Tohono Chul, but to the rest of the people out there? What is the context of these relationships from the past?
Escaping the task of watering in the hot sun, I happily jumped on my PC. According to SEINet, a reputable botanical resource, the queen of the night root has been used to treat many conditions, including heart and skin ailments, as well as diabetes. The fruit, roots, and stalk have all been traditionally eaten. (source: https://swbiodiversity.org/seinet/taxa/index.php?taxon=Peniocereus+greggii&formsubmit=Search+Terms) Interesting. But what else?
The more I started to dig online, the more curious I became. Short blurbs in botanical descriptions stating its use as a food and folk medicine with no further explanation are easy to find. More in-depth articles are seemingly scarce. Some say that the tuber is edible, while others caution not to overconsume because of serious side effects.
Sifting through google scholar, I discovered a scientific journal article published just last year from the Universidad Nacional Autónoma de México called “Antidiabetic Sterols from Peniocereus greggii Roots”! Here is a little summary:
The university team studied a concentrated essence made from the roots of Peniocereus greggii and found that it contained six distinct chemicals with blood sugar stabilizing effects. In the scientific fashion, they tested these components on mice and muscle cells grown in petri dishes. Two of the chemicals were specifically found to promote insulin secretion and two others also hinted at improving mitochondrial function. (source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9026134/)
The biological actions of the decoction from the root is complex, so I’ll leave you to read the article if you wish. However, it really exciting to see traditional folk medicine getting scientific recognition in Mexico and to discover some of the secrets that the Queen holds. I hope to come back to the topic of her herbal attributes in the future as I uncover more insights. Till then, know that a flower is always more than just a flower.
By Tracey Till, Propagation Associate
Don’t miss the big night! Sign up for Bloom Watch emails here.
Be sure you select “Bloom Watch” on the dropdown menu!
Bloom Watch #5
Cruel Summer
This is when we remember why it’s called the desert. The insects in the trees seem to imitate the sizzling Sonoran heat. Critters take refuge in the shade and their cool burrows. They drink from the fountains and hoses as we water the flowers. Days are long and the sunsets beautiful. Saguaro seeds disperse in the full bellies of birds. Prickly pear fruit turns color.
Waiting for rain.
One of our dedicated gardeners, Shauna, performed her weekly duties of tending to the Queens by providing them with the necessary watering. Supplemental water ensures the vitality of these special plants during times of excessive heat and lack of rainfall.
“I’ve been watching, and the rain in the forecast keeps getting moved a day farther away,” she said. The buds we checked this week were between 40mm and 50mm.
“No real change from last week.” We are still approximately 1-2 weeks away from Bloom Night.
Cooking Up A Storm
The University of Arizona’s CLIMAS has this to say about our monsoon season:
“The monsoon is driven by the sun heating up the land and the Pacific Ocean at different rates, with land surfaces warming more quickly than the ocean. The warm land creates low-pressure zones as hot air rises… The moisture-laden monsoon air travels north to Arizona and New Mexico, encouraged by the pressure difference between the hot, parched southwestern air and the cooler Mexican air.” (source)
We might never know exactly why the Queen decides to bloom when she does, but from careful observations collected over the years in our little patch of desert, it seems to be closely linked with the occurrence of this pattern.
It’s a busy time and a slow time here in the desert. A hurry up and wait. Where there is water, there is abundant growth. In our nurseries and in the garden we are all trying to keep up with the vigor of our plants as they soak up this solar energy. But by mid-afternoon, there is a quiet in the garden. The desert has some time to herself.
Rebel Flower Update
If you’ve been keeping up with Bloom Watch, then you know that last week we had a rebel flower on our hands. One of the Peniocereus greggii buds decided to bloom ahead of schedule, catching our gardening staff by surprise.
As always, the unpredictable nature of these special plants is keeping us on our toes. But fear not, nature enthusiasts! The rest of the buds are on track and expected to grace us with their beauty in approximately 1-2 weeks.
Stay tuned for more updates as we inch near the arrival of the Queen (the rest of them, that is)!
By Tracey Till, Propagation Associate
Don’t miss the big night! Sign up for Bloom Watch emails here.
Be sure you select “Bloom Watch” on the dropdown menu!