2014: Ozarks Plant Exploration

When lengthening days with genial rays
Make green the waking earth,
With vasculum and trowel armed,
In search of crops that none have harmed,
The gentle botanist goes forth.

Gathered Leaves

In this first stanza from his poem “The Botanist,” Ernest Jesse Palmer describes the cherished job of a plant explorer. He drew on his own work collecting plants for the Arnold Arboretum, particularly in the Ozark Mountains of Arkansas and Missouri. Many collections have been brought to the Arboretum from this biodiverse area, most extensively by Palmer during his nearly fifty-year collecting campaign there. Other Arboretum explorers, including our founding director, Charles Sprague Sargent have also made important contributions. In 2014, Arboretum Keeper of the Living Collections, Michael Dosmann returned to Arkansas, accompanied by Anthony Aiello from the Morris Arboretum, Timothy Boland and Ian Jochems from the Polly Hill Arboretum, and Theo Witsell from the Arkansas Natural Heritage Commission.

Every day of their eight-day expedition seemed to bring a new, unsolicited snake encounter, and the team was nearly swept up in a tornado! In spite of the region’s startling nature, it yielded a number of successful seed, plant, and herbarium collections. The team collected one of the rarest oaks in North America, the aptly named maple-leaf oak (Quercus acerifiolia), originally discovered by Palmer on Mount Magazine, Arkansas in 1924. Multiple species already present at the Arboretum gained further genetic diversity, in particular the Ozark witch-hazel (Hamamelis vernalis), which was enhanced by three new collections.

Collecting in The Natural State

On October 1, 2014, the team arrived in the capital city of “The Natural State,” Little Rock, Arkansas, to spend the next six days collecting throughout the northwest highlands, predominantly in the forests of the Ouachita and the Ozark Mountains. The focus of the expedition was the acquire species endemic to this part of North America, as well as to sample from the southern or western populations of wider ranging species.

October 2

The team’s first day in the field was spent at a 170-acre property owned by Theo Witsell’s family about 20 miles west of Little Rock on the north fork of the Saline River. The property, aptly named “Frog Valley” by Witsell’s daughter for its tendency to flood, was home to a diverse collection of plants. His intimate knowledge of the Arkansas flora aided the team immensely. Large black tupelo (Nyssa sylvatica), sweet gum (Liquidambar styraciflua), and countless hickory trees (Carya spp) covered the area and the team made 18 separate collections that day.

They also began their encounters with the local fauna, finding evidence of recent wild hog rootings, and running into three species of snake. Their adventures continued during their dinner in Little Rock when a tornado spun through the area, causing the diners to retreat to the rear of the restaurant.

October 3

On Friday morning, the team packed and departed Little Rock heading for the Middle Fork Barrens Natural Area. Along the way, they made a detour to the cultivated beauty of the Garvan Woodland Gardens, located near Hot Springs. This beautiful, well maintained garden is owned by the University of Arkansas. It features an extremely engaging and educational children’s garden, as well as a spectacular post and beam wedding chapel.

After a taco lunch, the team arrived at the Middle Fork Barrens Natural Area. They spent a fruitful afternoon collecting and found six different taxa Taxon: In biology, a taxon (plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. in the woods and fields, including the southern toothache tree (Zanthoxylum clava-herculis) a relative of the plant that produces Sichuan pepper.

October 4

The team left Hot Springs in the morning for a location about 15 miles northwest where Theo Witsell had seen specimens of rock maple (Acer saccharum ssp. leucoderme). After a bit of searching, the Polly Hill contingent located their quarry along Cedar Fourche Creek.

From there they were on to the main collecting location of the day, the Kings River Falls Natural Area in Madison County, near Fayetteville. They spent the afternoon hiking along Mink Creek where they hoped to locate a rare species of hawthorn (Crataegus phaenopyrum). While they managed to locate several hawthorns, they were in poor condition and not in fruit. They had better luck with other taxa, finding an example of Ozark witchhazel (Hamamelis vernalis), American hazel (Corylus americana), and a chinkapin (Castanea ozarkensis) in fruit. In all, they made five separate collections.

October 5

Sunday’s activities began with a visit to the Crystal Bridge Museum of American Art in Bentonville to see the remarkable collection assembled by the Walton family. From there, the team returned to Kings River Falls for more field collecting, concentrating on the banks of the Kings River itself. The explorers were struck by the profusion of witchhazel along the banks that would make a beautiful show when it bloomed in February. Their collections were two taxa, the pink-flowered early azalea (Rhododendron prinophyllum) and blackhaw viburnum (Viburnum prunifolium). They had another run in with the local fauna when Ian Jochems discovered a western cottonmouth snake (Agkistrodon piscivous leucostoma) at his feet during a rest stop on the trail.

October 6

On their penultimate day in the field, the team headed south to Mount Magazine State Park in Logan County. The landform, which is the highest point in the state (2753 feet or 839 meters, above sea level), rises up as a mesa from the surrounding forest. Their target plant that day was the critically imperiled maple-leaf oak (Quercus acerifolia), which is only found in four locations in Arkansas. As the team hiked up along the trail they began to see the shrubby, multi-stemmed trees, but unfortunately, none of them bore any acorns. They collected genetic material however, in the form of leaves preserved in silica. On their way back down the mountain, they encountered an additional group of maple-leaf oaks. On one tree there were three acorns that they gathered for each of their institutions.

October 7

The team rose early in preparation for their return to Little Rock. On their way back they stopped for a bit more collecting at the Ouchita National Forest. There in a wooded area in very gravelly soil they gathered plants of bigleaf snowbell (Styrax grandifolius). These plants grew as suckers from parent plants nearby. They also located a species of azalea (Rhododendron viscosum) and collected some seedlings. After returning to the city later that day, the team finished cleaning and packing their collections for their departure the next day.

October 8

On Wednesday the team prepared to leave The Natural State. The herbarium specimens were sent to the Arnold Arboretum, for preparation and mounting. All of the seed went to Polly Hill Arboretum for cleaning, processing, and distribution. The seedlings were divided among the participants and hand carried back to our institutions. Anthony Aiello took all the collection notes and data and compiled it into a digital format.

By the time they departed on October 8th, the team had gathered 34 different species and 36 distinct collections, including several new taxa for all three arboreta such as a new genus related to elms, Planera, and a new species, the southern prickly-ash (Zanthoxylum clava-herculis). The rich biodiversity of Arkansas demonstrated that explorers could return to The Natural State in the future to make more noteworthy botanical collections.

Back in Boston

Collections from this expedition have been successfully propagated at the Dana Greenhouses. They are now growing on the grounds. See their locations in ArbExplorer.

Dig Deeper

Learn more about threatened plants at the Arboretum, including the maple-leaf oak.

Ernest Jesse Palmer collected plants throughout the Ozarks, read about it here.