Roll Out the Green Carpet: A Star Is Born in the Greenhouse

What is old is new again.

The dinosaur of the plant kingdom, a Wollemia pine tree (Wollemia nobilis), has surprised horticulturists at the Chicago Botanic Garden with a burst of promising male and female cones this winter.

In Glencoe, the sole tree spends its winters in the carefully controlled environment of the production greenhouse. In the wild, its relatives are clinging to life on remote sandstone gorges in the Blue Mountains of Australia.

“It is probably the most watched plant in the Garden right now,” said Boyce Tankersley, director of living plant documentation. Little is known about the prehistoric species that is part of a genus dating back 65 million years. The Garden’s specimen is a youthful 8 years old, and is just beginning to show off its unusual characteristics.

“In this case, there is such little information in the literature,” noted Tankersley, who was amazed to see both male and female cones emerging from the tree’s branches earlier this year. “We don’t know enough about this plant to know if it is going to set seed…but at least it is producing cones, which will allow us to try some experiments,” he said. The tree has grown male cones in recent years, but this is the first year it has produced any female cones.

PHOTO: Wollemia nobilis female cone.
Wollemia nobilis female cone
PHOTO: Wollemia nobilis male cone.
Wollemia nobilis male cone

Scientists do know that the species that has managed to survive the test of time possesses some unusual adaptations. It can generate new seedlings by dropping specific branches that take root, or it can exchange pollen from male to female cones to generate seed.  

At the Garden, scientists plan to pollinate the tree when the time is right. They will use pollen from the tree itself, and if available, pollen from a tree at another botanic garden. They will also reserve pollen for a potential future exchange.

PHOTO: Wollemia nobilis in the Heritage Garden in summer.
Find Wollemia nobilis in the Heritage Garden in the summer months.

Trees in the wild population are believed to be closely related to one another. As a result, any seeds they produce have a low level of viability. Only 6 percent or fewer go on to become healthy, mature trees. The species is listed as critically endangered. The urgency to save the pines is accelerated by changes in climate. Their mountain home is experiencing increasingly hotter and drier weather than ever before.

According to Tankersley, there is hope that more diversity may be found within the propagated plants, and that their offspring could lead to a stronger future for the species. However, scientists are only mildly optimistic. “In a world where there is so much that we can’t do anything about, it’s good to have something where you can participate in efforts to keep something from going extinct,” he said. “This plant is not gone; there’s something we might be able to do to help it out.” In addition, the plant may inform the research of paleobotanists who rarely have the opportunity to see a live plant with such historic roots to compare against the fossil record. “In a scientific way, we’ve been looking at the earth in a relatively short period of time,” added Tankersley. “When we find something like this that is very uncommon, everything about it is unknown…it’s sort of a miniature warehouse that we don’t want to lose because in the future, it may be more important than a mere botanical curiosity.”

The horticultural team also takes the cone production as validation that they are meeting the plant’s very particular growing requirements.

The Garden’s Wollemia pine spends its summers in the Australia bed of the Heritage Garden. Tankersley anticipates that it will be back on display this June.

As for the voyage of discovery with this extraordinary plant, he says, it is to be continued…


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Conifornia Dreaming

In early September, I had the privilege of attending the annual meeting of the American Conifer Society in Sonoma County, California. My first (and wildly inaccurate) thought was, “What could we possibly see aside from redwoods? There aren’t any conifers that thrive in that area.” Well I couldn’t have been more wrong, as the next two days showed me.

PHOTO: Tour at the Golden Gate Bridge.
In the early days of colonial settlement, the hills surrounding the Golden Gate Bridge were covered with forests of lush coastal redwood (Sequoia sempervirens).

Our first day included stops at one private garden, Hog Hill; a trip to an old growth redwood forest; and a very informative demonstration by the Aesthetic Pruning Association. Hog Hill is notable for having a dawn redwood (Metasequoia glyptostroboides) that is likely one of the very first grown from seed after being rediscovered in China in 1941. The rest of the garden featured a wide array of South African and Mediterranean plants that were well suited to the semiarid climate.

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Redwoods in Armstrong Woods

The part of the trip I was looking forward to most was next. After waiting my entire life to see them, I was finally getting to see coast redwoods in their home. While I’ll never be able to grow them here in the Chicago area, it was still inspiring to see such majestic trees in person. Armstrong Woods State Natural Reserve was owned by a lumberman in the 1880s who recognized the area’s beauty and set aside this tract of land as a public park. While it doesn’t contain the largest trees in California, it still is home to an outstanding number of trees. Nothing reminds you of how big the world is like standing next to a plant more than 300 feet tall! We also had a chance to take a guided walk with docents from the park, where we learned that the vast majority of wildlife resides way up in the canopy, which explains why the forest floor was so eerily silent. 

After touring the redwoods, we traveled to Circle Oak Ranch, an equine center that also features an amazing collection of dwarf conifers. Unfortunately, my camera’s battery was dead by this point, so I don’t have any photos to share. We were treated to a tour of the gardens followed by an outstanding pruning demonstration by the Aesthetic Pruning Association. Several volunteers were stationed throughout the gardens giving demonstrations on how to properly prune various growth forms of dwarf conifers. This garden was also a highlight, because it was located in an area that experiences colder temperatures and heavy clay soil, and therefore featured numerous plants that would also thrive in our midwestern climate.  

Quarryhill Botanical Garden
Quarryhill Botanical Garden

The following day was a trip to Quarryhill Botanical Garden. Quarryhill features a vast collection of temperate climate Asian plants. More than 90 percent of the plants were grown from wild collected seed in places ranging from Japan to India. The gardens date from the late 1980s, when the property owner at the time decided to convert the abandoned rock quarries on her property into a lush garden. Quarryhill included many unusual conifers in their collection, which made it a great opportunity to see plants I will likely never see again such as Pinus roxburghii and Cupressus chengiana.

However, I will admit that my favorite plant from the garden ended up being—of all things—a rose. Rosa roxburghii features very large (nearly golf-ball-sized) hips of vibrant yellow with small, reddish spines covering their surface. Sure, it might not be conifer-relevant but it never hurts to learn a new plant, right?

PHOTO: Rosa roxburghiii at Quarryhill Botanical Garden.
Rosa roxburghiii at Quarryhill Botanical Garden
PHOTO: Pinus roxburghii.
Pinus roxburghii
PHOTO: Wollemia nobilis.
Wollemia nobilis

Our final stop on the trip was the San Francisco Botanical Garden (formerly Strybing Arboretum). Their 55 acres packed an incredible number of plants into one place. The conifer highlight of the garden was a very rare albino redwood. Unable to survive on their own, albino redwoods are mutations that lack chlorophyll, typically found growing at the base of an otherwise normal redwood tree. Other highlights included some magnificent specimens of conifers from the Southern Hemisphere including Araucaria and Wollemia nobilis, a tree that was only known from the fossil record until 1994, when a small grove was discovered near Sydney, Australia. We are fortunate to have a specimen of Wollemia on display in our Heritage Garden as well, but it was exciting to see a larger specimen such as this.

PHOTO: Albino redwood at San Francisco Botanical Garden.
Albino redwood at San Francisco Botanical Garden

In addition to seeing such an amazing array of plants in two days, this trip also gave me the opportunity to meet dozens of other professionals and hobbyists who share my love of conifers. The amazing thing about trips like this is seeing just how much there is in our world and how important it is to share ideas and see new things. If I had never taken this trip I would probably go on thinking that everything in northern California east of the coastal hills was a barren grassland, not an area teeming with native plants, and I never would have had a chance to meet so many interesting people, each with their own unique take on the world of conifers.


©2015 Chicago Botanic Garden and my.chicagobotanic.org