Studying Fungi Amid the Ghost Orchids

Undercover Science

Julianne Beck —  January 24, 2017 — 1 Comment

Just like magic, a ghost orchid (Dendrophylax lindenii) appears overhead in a Florida swamp. Its pale roots extend like gloved fingers across the bark of a pond apple tree (Annona glabra), while its graceful flower reflects onto the shadowed water below.

Epiphytic ghost orchid roots cling to pond apple tree. Photo @ Lynnaun Johnson

Epiphytic ghost orchid roots cling to a pond apple tree. Photo @ Lynnaun Johnson

Doctoral student Lynnaun Johnson wades over for a closer look. Habitat is shrinking for this reclusive orchid, and he is using a unique approach to better understand the species’ uncommon lifestyle.

During March 2016 fieldwork in the Florida Panther National Wildlife Refuge, Johnson went deeper every day—even when it meant paddling his canoe within 10 feet of a sunstruck alligator to reach the widely dispersed plants. Each time he located an orchid, he looked past the plant and took a sample from the bark of its host tree.

“What I’m interested in primarily is identifying the fungi within the habitat of these particular orchids,” said Johnson. “If you are going to place a ghost orchid out in nature and it can’t acquire nutrients or it doesn’t form the right associations with mycorrhizal fungi, it’s not going to survive,” he explained. “If these trees have a particular suite of fungi, that might be something that we need to consider in terms of a healthy population.”

Species within the orchid family are generally known to depend on fungi to help them through key stages of life, such as growing from a seed into a seedling. But there are differences in how those partnerships work. When an orchid lives in soil, the fungi help move water and nutrients to and from the roots. But when the orchid lives on a tree, scientists are less certain of what occurs.

Lynnaun Johnson wades toward a ghost orchid.

Lynnaun Johnson wades toward a ghost orchid.

Until recently, they believed that orchids growing on trees were less likely to depend on fungi long term. This belief was encouraged by the discovery that the prominent roots of plants like the ghost orchid actually conduct photosynthesis—a process in which sunlight becomes sugar. That process is managed by leaves in many other orchid species. If the roots are so full of nutrients, do they really need any help from fungi?

A ghost orchid grows in the wild. Photo © Rebecca Weil.

A ghost orchid grows in the wild. Photo © Rebecca Weil.

They sure do, said Johnson and his collaborators, who examined the roots of another tree-bound orchid species, the vanilla orchid (Vanilla planifolia). Using modern technology called high-throughput sequencing that can produce more detailed results than ever before, they found that epiphytic orchids—those that grow on trees—also rely on fungi to carry out essential functions. “We know the importance of photosynthesis, but that doesn’t mean if a plant is photosynthesizing it’s healthy. It means it will continue to rely on fungi to grow and develop,” said Johnson. He recently documented the presence of fungi in the roots of ghost orchid root samples from his field work.

Back in the field, Johnson wondered if the type of fungi present on certain tree species is what led the ghost orchids to select them as their home over other trees. In the Florida refuge, the orchids are found only on pond apple and pop ash trees (Fraxinus caroliniana). So during his fieldwork, he sampled both types of trees, some with and some without orchids. As a point of comparison, he also sampled the bark of bald cypress trees (Taxodium distichum). He plans to conduct more fieldwork this spring before examining the bark for fungi.

The number of ghost orchids in Florida has dwindled as more and more swamps have been drained to build new housing complexes to accommodate a growing population. There have also been times when the trees in the swamps were logged.

Lynnaun Johnson samples bark.

Lynnaun Johnson samples bark.

Johnson will later examine the roots of other orchid species that neighbor the ghost orchids on trees. This will further clarify the importance of fungi to the ghost orchid, which he suspects relies on the fungi more than neighboring orchid species. He also has his eye on a population of orchids growing naturally in Cuba on a larger number of trees that he hopes to study as well.

Johnson aims to help people understand that there is more than a one-to-one relationship in nature, and that multiple partnerships contribute to the health of each species and system. For example, “if we understand the significance of host trees, then we can preserve both the host trees and epiphytic orchids at the same time,” he said.

Orchids may become a lifelong pursuit for Johnson, who moved to Illinois from his childhood home on the island of St. Lucia to pursue his studies. He hopes to specialize in the study of fungi as it relates to plants and the conservation of wild lands and waters.

Read more about orchid research at the Garden, and be sure to visit the Orchid Show, open February 11 through March 26, 2016.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Seed saving is an art, not to mention fun and empowering. Plus, it’s a valuable contribution on a deeper level: agricultural biodiversity matters, and seed saving in home gardens is mainstream conservation of biodiversity!

PHOTO: John Withee bean collection.

A highlight of our 2013 Seed Swap was the John Withee bean collection. A family tradition of “beanhole” cooking led John Withee to collect and organize 1,267 bean varieties. He donated the collection—and its handcrafted case—to Seed Savers Exchange before he passed away.

Here’s why you, the home gardener, should start a seed collection:

Seed saving promotes self-reliance, and swapping seeds connects and builds community. It connects us to our agricultural roots. Additionally, it helps conserve our agricultural resources. Preservation matters. Once varieties are lost, they cannot be recovered. A century ago, seed houses had hundreds of varieties, and now just a few remain. Think about this vegetable fact: In 1903, 544 varieties of cabbage were listed by seed houses across the United States. By 1983, just 28 of those varieties were represented in our national seed bank at the National Seed Storage Laboratory (now the National Center for Genetic Resources Preservation).

Saving seeds encourages adventurous eaters. Growing heirloom varieties holds culinary appeal because it offers the opportunity to grow interesting vegetables that aren’t readily available in grocery stores.

Thrifty seed collectors save money because there is no seed to buy each spring. They maintain a personal seed collection.

Seed savers are lifelong learners, and home gardeners play an important role in helping to preserve our diverse seed histories. Home gardens become living laboratories to learn about plants. Seed saving builds observation skills, and there is a need for more seed growers to evaluate varieties for disease resistance and variety. 

Finally, saving and sharing seed just feels good. 

PHOTO: Broccoli seedlings

Broccoli seedlings

Which seeds should be saved (and are the easiest to save)? 

Deciding which seeds to save requires a working knowledge of several definitions:

Hybrid varieties (F1) produce seeds that, when grown the next year, are unlikely to resemble the original plant. Don’t save seeds from a hybrid vegetable. Seeds should be saved from open-pollinated plants (OP), those stable varieties that can reliably reproduce themselves generation after generation. As long as open-pollinated plants don’t cross pollinate with other varieties of the same species, their offspring will carry the distinguishing characteristics of the variety. Heirloom vegetables are open-pollinated plants that produce seeds passed down from one generation to another, often with historical connections and stories. Heirlooms carry special value and are usually old varieties.

Deciding which seeds to save requires a basic understanding of how plants reproduce:

Very simply, plants either mate with themselves or they mate with other plants. Self-pollinating plants have all the flower parts (anther and stigma) to transfer pollen within their own flowers (achieved by physical contact of male and female parts), or between separate flowers on the same plant (helped by wind or insects). In other words, they mate with themselves. Cross pollination takes place when pollen is transferred from one plant to another plant by insects, birds, or wind. Crossers can’t move pollen without help as the selfers do. Offspring of plants that cross pollinate may have different characteristics than the original variety unless they are isolated from plants of the same species.

Seed packet with description designating F1 seed.

If a package is labeled F1, seeds should not be saved, as they are unlikely to reliably reproduce the same plant as the parent.

A couple of tips on planning a garden for seed saving:

  • Start small and keep it simple.
  • Balance the many factors that comprise the art and practice of seed saving.
  • Begin by choosing a couple of self-pollinating annuals. Peas, beans, tomatoes, and lettuce are easiest to save. Insect- and wind-pollinated annuals may require isolation distances so they don’t cross pollinate.
  • Thoughtfully map out the garden to make efficient use of space. Growing plants for seed may take up more room for a longer period of time. While radish may be harvest-ready after growing 30 days, it may take much longer for your radish crop to produce its seeds.  

Take our classes during the Super Seed Weekend to learn more about planning a garden for seed saving.

Seed savers contribute! Come to learn, swap seeds, and share stories at Super Seed Weekend and experience the satisfaction that comes along with being a seed saver. A broad community of seed savers (new friends) awaits!


©2017 Chicago Botanic Garden and my.chicagobotanic.org

There are heirloom seeds from corn grown by Native Americans in Pennsylvania, and seeds from a marigold grown in the Andes for the spice of its leaves, along with some 4,500 other varieties in the collection of William Woys Weaver, Ph.D.

Hear William Woys Weaver in person at 1:30 p.m. on January 22. Register for his free lecture here.

PHOTO: William Woys Weaver

William Woys Weaver

Every heirloom plant seed grown for food has a story, according to Dr. Weaver. Where it came from, who it was grown by, and why it was grown all are pieces of that history. It has a past and a future. The food historian will share the story of these seeds, and of the collection his grandfather began in about 1932 that he now oversees, on Sunday, January 22, during Super Seed Weekend at the Chicago Botanic Garden.

Weaver’s collection is housed in a seed room in a historic home in Pennsylvania. Built around 1805, the home is listed on the National Register of Historic Places and sits on a two-acre kitchen garden that Weaver and his collaborators task with growing and testing seeds from the collection. They employ an artisanal process, doing everything by hand. If the seeds look successful, they are moved on to a university or qualified farm to expand the process.

“People are beginning to realize these heirlooms, organically raised, are much more nutritionally rich than seeds grown commercially,” Weaver said. “We are right at the cusp of a lot of ideas.”

The Roughwood Seed Collection is now home to the largest privately held collection of its kind in the state. The collection is part of the Roughwood Seed Archive, a nonprofit 501(c)3 organization with a working board. Weaver and his team are making big plans to grow and customize their endeavor to better serve the demand from local chefs and the growing list of those who are tuned in to the origins of their food. “A collection like this is very important because this is a source of food locally and farmers can get seed from us. It has a value far beyond its monetary cost,” Weaver said.

PHOTO: Heirloom tomatoes

Heirloom tomatoes—just one of the many heirlooms worth saving and sharing

Learn more with a class at our expanded Super Seed Weekend. Receive free parking with your paid class registration.

Start Your Own Kitchen Garden

Weaver encourages home kitchen gardeners to start small when growing heirloom seeds for food, and see where their talents are strongest. He suggests joining a seed exchange to gain access to a wide variety of options, but focusing on growing only what seems to do well and obtaining the rest of their produce from other growers.

Weaver hopes that people who participate in community gardens or seed exchanges enjoy the connectedness that comes with the process. “The seed exchanges and the seed networks help build a sense of community, so it’s very important from a social aspect, and also the heirlooms are good teaching tools for kids,” he said. It’s helpful to teach and learn about where our food comes from and what resources—including a grower’s time—go into each fruit or vegetable produced. When we understand those elements, Weaver said, we are more likely to appreciate each bite on our plate, and less likely to waste or toss edible food.

Weaver is eager to establish new systems and opportunities for the Roughwood Seed Collection in the very near future. The ambitious food advocate is also a professor and an author, with a new book on pickling that is due out in 2018, and a forthcoming update to his popular book, Heirloom Vegetable Gardening.

Don’t miss the exciting conclusion of Super Seed Weekend. The Seed Swap begins at 3 p.m., right after Weaver’s 1:30 p.m. lecture, “Our Kitchen Garden for Culinary and Cultural Research: The Roughwood Seed Collection,” on Sunday, January 22.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

Repotting Cactus

Tom Weaver —  January 10, 2017 — 1 Comment

Repotting a cactus can be intimidating, but a few simple tricks can make the project a lot less painful—and result in beautiful, healthy plants.

When repotting a cactus, there a few essential tools you’ll need:

  • Chopstick or small dowel
  • Cactus soil
  • Container with drainage
  • Gloves
  • Newspaper

Cactus soil is a special blend of potting soil that is formulated for fast drainage. It is usually a blend of peat moss and sand, sometimes including coconut fiber, perlite, or vermiculite. With the increase in popularity of growing cacti and succulents, it has become a garden center staple and can be found at most garden centers and hardware stores.

View video on our YouTube channel

You’ll want to use a container—preferably one that is made from terra cotta—with drainage holes. This allows the water to drain away from the roots rapidly. Cacti are native to dry environments and do not like to have their roots sitting in water. If the drainage hole on your pot is especially large, it can be partially covered with a rock to prevent soil from draining out the bottom when you water. Most cacti are slow growing and should never be planted in a pot that is more than an inch larger in diameter than their previous container. This is to help prevent rot.

Winter is a great time to warm up in the Greenhouses and see our cacti collection.

Weingartia lanata in bloom.

Weingartia lanata in bloom

Repotting your cactus is in many ways very similar to repotting almost any other houseplant.

  1. Begin by filling the new pot ½ to ¾ full with soil.
  2. Remove your plant from its old pot. 
    • Make sure to wear gloves.
    • Roll up a sheet of newspaper to make a strip approximately the same width as a belt. 
    • Wrap your newspaper strip around the plant and use it as a handle to gently lift the plant from the pot.
  3. If the plant is really root bound, gently loosen the soil around it to encourage new growth. (I like to leave some of the soil intact. This provides some weight to help keep the plant anchored. If the soil is poor quality, all of it should be removed.)
  4. Using the newspaper handle, set your plant into its new pot.
  5. Using the chopstick, firm the soil around the base of your plant. Keep adding soil until it reaches the same level as the old soil. (This should be approximately ½-1 inch below the lip of the container.)
  6. Water your plant throughly. 

Your cactus now has much more room to grow, which also means much more soil to stay moist. Make sure to check before watering again—the soil can stay moist for a long time, even if it is a mix made for cacti.


©2017 Chicago Botanic Garden and my.chicagobotanic.org

One of my favorite volumes in the Lenhardt Library’s rare book collection (although I love them all) is Autumnal Leaves by Ellen Robbins, published in 1868. Each of the 18 original watercolor paintings of autumn leaves looks so true-to-life that you want to reach out and pick a leaf off the page.

Sumac illustraion from Autumnal Leaves by Ellen Robbins.

Sumac from Autumnal Leaves by Ellen Robbins

This volume, specifically, the sumac watercolor, will be on display at the Philadelphia Museum of Art, in the American Watercolor in the Age of Homer and Sargent exhibition which runs March 1 to May 14, 2017. I’m delighted that an East Coast audience will have the opportunity to share this treasure.

Although we’ll miss the book while it’s away, through the Lenhardt Library’s digitization program, each page of the book is viewable in the Illinois Digital Archives repository.

You’ll find the sumac shown here on page 4 of the content list. View the full collection of prints here: http://www.idaillinois.org/cdm/compoundobject/collection/ncbglib01/id/3364/rec/2

Additionally, the sumac will be published in the American Watercolor in the Age of Homer and Sargent exhibition catalog.

A unique, one-of-a-kind book, this is the only copy listed with holdings in a library.

Bound with gold tooling and gilt edges, the volume is quite brittle and fragile. It has just been conserved by a professional book conservator to prepare it for exhibition.

Inside front cover, marbling, and bookplate for Ellen Robbins' Autumnal Leaves, published in 1868.

Inside front cover, marbling, and bookplate in Autumnal Leaves, published in 1868

Read more about Ellen Robbins and her extraordinary life and talent from retired curator of rare books Ed Valauskas in one of his Stories from the Rare Book Collection: Ellen Robbins, New England’s extraordinary watercolorist and floral artist.

Discover more about the current and rare books in the Lenhardt Library’s collection, which is open to the public. Members have borrowing privileges—become a member today!


©2016 Chicago Botanic Garden and my.chicagobotanic.org