TEMPE -- After years of careful experimentation, the Desert Botanical Garden has celebrated a milestone in its effort to save an endangered orchid.
For the first time since the project began in 2016, two of the fragile Canelo Hills Ladies� Tresses orchids have flowered, offering a hopeful sign for the future of this rare species which can only be found in southern Arizona.
The process involves delicate germination and propagation techniques aimed at rebuilding the wild population. While the journey has been long and challenging, the recent blooms mark a significant achievement for both the botanists involved in the project and the future of the orchid.
“It means that maybe this plant has a chance of survival,� said Steven Blackwell, conservation collections manager at the DBG.
Also known as Spiranthes delitescens, the orchid is native to southern Arizona and grows in cienegas, or desert wetlands. It has previously been identified in just five locations in southern Arizona. Erin Creekmur, stewardship program director for the Nature Conservancy, said the orchids have not been found in its Canelo Hills Cienega Preserve since around 2010. The preserve is owned and protected by the conservancy.
Steve Frowine, a horticulturist and author of eight books about orchids, said most orchids are from tropical areas of the world, so the ones found in more temperate areas are difficult to find, closer to the ground and don’t produce as large of flowers.
He called the successful propagation of the Arizona orchid “a great accomplishment.�
The DBG worked with the U.S. Fish and Wildlife Service, the Smithsonian’s North American Orchid Conservation Center and the Nature Conservancy to preserve the remaining populations and propagate new plants with the goal of reintroducing them. Blackwell said his team learned a lot about different orchid reproduction techniques from botanical gardens involved in the Smithsonian’s orchid conservation center.
Blackwell said the DBG was asked by the Fish and Wildlife Service to get involved because of the plant’s risk of extinction.
The project started in 2016 with building a seed bank, and propagation began in 2020. Blackwell said they used seeds from another species, the Ash Meadows Ladies� Tresses (Spiranthes infernalis), to practice and hone their technique before germinating seeds from the much more rare Canelo Hills variety.
The process starts with sterilizing the dust-like seeds. Next, the seeds are placed onto a petri dish with media that mimics the fungus they need to germinate in the wild. After they have grown a quarter inch to half inch, they are placed in glass jars to grow their roots before they are repotted into a special orchid media. Blackwell said it’s about a three-month process from germination to placement in glass jars. From there, it’s about a year before the plants are ready to be transferred to a pot containing special orchid soil.
Blackwell said this is the first time they have been able to get one of the plants to flower. That plant was started in 2022.
“This is a huge win for conservation and being able to hopefully bring these species back into these landscapes once we get them to a place where habitat can really support them,� Creekmur said.
Cienegas have significantly reduced in area because of agricultural expansion, groundwater depletion, erosion and climate change, according to the Nature Conservancy’s website. Blackwell said habitat loss is the species� biggest threat. The Canelo Hills Ladies� Tresses orchid was described as a new species in 1990 and listed as endangered by 1997. It is now considered critically imperiled, according to the DBG.
“We estimate that in the desert Southwest, the cienega habitats only account for about 2% of the regional area, but over 20% of our endangered and threatened species are tied to those cienegas,� Creekmur said. “So cienega preservation really is a key conservation objective.�
Blackwell said less than 300 orchid plants remain in the two places where they are found in southern Arizona near the ghost town of Canelo. Even more concerning, he said, is that less than 20 were found at one of the sites on the last check.
These orchids can be challenging to find in the wild. They typically grow between 1 and 1.5 feet tall at full maturity, and the flowers are delicate and small. Adding to the difficulty in reproducing, they don’t flower every year. To help with their search efforts, the DBG worked with Lauralea Oliver, owner of K9inSCENTive, a California-based ecological scent detection training service.
Two dogs, Circe and Muon, were trained to identify the scent of the Ash Meadows Ladies� Tresses, which grows in Nevada, just outside of Death Valley. Once the dogs successfully identified that species, they were brought to Arizona to see if they could identify the Canelo Hills Ladies� Tresses orchid.
Blackwell said that within 20 minutes of being released, the dogs found a small Canelo Hills plant that wasn’t in flower.
Blackwell said he hopes he will be able to use the same methods of propagation with other endangered orchids as well as several cactus species in southern Arizona and western New Mexico.