Deep within one of America’s most inhospitable landscapes, Lynnaun Johnson finds himself staring at a “ghost.”
The Dendrophylax lindenii, or ghost orchid, has a storied past. Travelers hoping to spot the most-recognizable native orchid in the United States have to traverse the alligator-infested swamps of South Florida. Still prominent in Cuba, the plant is listed as endangered in the United States, largely due to habitat destruction and over-collecting. Once prolific, the ornamental orchid’s numbers have dwindled to an estimated 2,000 plants.
“My research will be important for conserving the ghost orchid in situ,” says Johnson, a doctoral student in Northwestern’s Program in Plant Biology and Conservation (PBC). “Scientists have already determined which fungi are critical for ghost orchids early in life, but we need to examine them as adults to learn exactly how they survive.”
Fungi play an important role for the orchid because the plant’s seeds lack nutrients and therefore need help to germinate. Only once the right fungus has been introduced can an orchid embryo grow.
Researchers at the University of Florida have successfully reintroduced 80 ghost orchids to South Florida after cultivating them from seeds in a lab.
Making the plant more peculiar is that as an adult it lacks leaves, though its roots have photosynthetic capabilities. Ghost orchids are also purely epiphytic — their roots grow wrapped around trees — rather than terrestrial, or soil-bound.
“Complimentary research has shown that leafless orchids rely more on fungal partners during adulthood,” says Johnson, whose dissertation advisor is Gregory M. Mueller, a PBC member and Negaunee Foundation Vice President of Science at the Chicago Botanic Garden. “By studying the fungus, we hope to learn more about the overall distribution and abundance of the orchids.”
The PBC is an educational collaboration between Northwestern and the Chicago Botanic Garden that has resulted in more than 50 masters’ degrees and two PhDs. Johnson is one of 15 students currently pursuing their doctorate as part of the program.
Johnson’s first foray into plant research came as an undergraduate at Illinois College, where he helped to germinate threatened and endangered orchids for reintroduction into the plants’ native habitats. Growing up in St. Lucia and the Bahamas, Johnson recalls the natural world at his fingertips as a child.
Since joining Northwestern in 2013, Johnson has also conducted research on the vanilla orchid. The results of that two-year study help illustrate how the plants rely on distinct fungal communities for both its epiphytic and terrestrial roots to pull nutrients.
“The PBC has provided opportunities for me to collect samples and attend workshops while faculty have guided me to use techniques I might not have otherwise considered,” says Johnson, who also credits Northwestern’s affiliation with the Field Museum of Natural History with helping provide space to process his orchid samples. Johnson was recently awarded the Missouri Botanical Garden’s Catherine Beattie Fellowship to continue his research on the endangered flora.
“Eventually, I would like to visit Cuba to explore the nation’s distinct ghost orchid population in the hope that we might find a way for the plants continued survival in the United States,” says Johnson.