The Lady Slipper newsletter of the Kentucky Native Plant Society has been published since the Society’s founding in 1986. This is one of a series of reprints from past issues. This article, about sweet fern (Comptonia peregrina), first appeared in Vol. 26, No 1, Spring 2011. If you would like to see other past issues, visit the Lady Slipper Archives, where all issues from Vol. 1, No. 1, February 1986 to Vol. 35, 2020.

Sweet fern—A rare Kentucky shrub with an interesting history

By Tara Littlefield, Botanist, Kentucky State Nature Preserves Commission

The wax myrtle or bayberry family (Myricaceae) is known for its odor. These plants have resinous dots on their leaves, making their leaves aromatic. Plants in this family have a wide distribution, including Africa, Asia, Europe, North America and South America, missing only from Australasia. Myricaceae members are mostly shrubs to small trees and often grow in xeric or swampy acidic soils. More familiar members of the wax myrtle family include many in the Genus Myrica (sweet gale, wax myrtle), some of which are used as ornamentals and are economically important. In addition, the wax coating on the fruit of several species of Myrica, has been used traditionally to make candles.

So what does this interesting family have in common with Kentucky’s flora? We are lucky to have just one species in the wax myrtle family, Sweet fern (Comptonia peregrina). In addition, it is also a monotypic genus restricted to eastern North America. This means that the genus Comptonia has only one species (C. peregrina) worldwide, and just happens to be found here in KY! Of course the common name sweet fern is misleading. This woody shrub is certainly not a fern. However, the leaves have a similar shape to pinnules of a fern frond (leaf). But having sweet in the common name is no mistake. If you crush the leaves throughout the growing season, a lovely smell is emitted as the essential oils volatilize into the air.

Sweet fern is a clonal shrub that grows up to one meter high and spreads through rhizomes. The leaves are alternate and simple, linear and coarsely irregularly toothed, dark green above and a bit paler below. It is monoecious (meaning male and female flowers on different plants). The female flowers are not showy— short rounded catkins [dense cluster of apetalous flowers, usually associated with oaks, birches and willows] with reddish bracts. The male flowers are elongated yellow-green catkins clustered at the branch tips, the pollen being adapted to wind dispersal. The fruit is a round, bur-like cluster of ovoid nutlets that turn brown when mature in late summer. The bark is reddish and highly lenticeled (small corky pores or narrow lines on the bark that allow for gas exchange).

While very common in the northern part of its range (northeastern United States and Canada), sweet fern is state listed endangered in Kentucky, along with being state listed as rare inOhio, Tennessee, South Carolina, West Virginia, Georgia, and North Carolina. The populations of sweet fern in the southern part of its range are isolated and disjunct from the common habitats up north. There seems to be a close association of these remnant populations with the Appalachian Mountains, which suggests that the populations in the southern ranges remained in protected “refugia” during periods of great plant migrations, such as during glaciations.

Sweet fern is typically found in openings in coniferous forests with well drained dry, acidic sandy or gravely soils with periodic disturbances. In the north, it can be found in pine-oak barrens or jack pine and spruce forests that are maintained by fire, creating openings and decreasing competition. It has also been noted to colonize road banks and even highly disturbed soils such as mined areas. Contrary to these open coniferous habitats with periodic fire, the remnant populations of sweet fern in Kentucky and Tennessee are found on sandstone cobble bars, which are maintained by annual floods. Despite being found on habitats that are maintained by different disturbance regimes, these two communities share a few things in common—they are both dry, acidic, sandy and nutrient poor. Disturbances are a natural occurring impact in these communities that removes shrubs and saplings, thus decreasing competition so that sweet fern can thrive.

Sweet fern has adapted to these specialized habitats. It is a fires adapted species; it will resprout after a fire and increase its clonal sprouts through underground rhizomes. It is also a xerophyte, a plant adapted to dry conditions. And since it is adapted to living in nutrient poor, acidic soils, it has evolved with the bacteria Frankia that fixes nitrogen, somewhat like the more famous nitrogen fixing legumes who have partnered with the bacteria Rhizobium. Did you know that there are over 160 species of nonleguminous plants that fix nitrogen? It is also the host of the sweet fern blister rust (Cronartium comptoniae) which reduces the growth of pines, particularly Jack pine. What interesting relationships this shrub has with bacteria and fungi! In addition, sweet fern is the food plant to larvae of many species of Lepidoptera (moths and butterflies). These include the Io moth (Automeris io), and several Coleophora case-bearers (some of which are found exclusively on sweet fern).

But perhaps the most fascinating facts about the rare shrub sweet fern is what it can tell us about the evolution of plants, the history of the earth, and the paleovegetational past of Kentucky. Geologically speaking, sweet fern is an old plant. In Kentucky, it was most likely more common some 20,000 years ago during the last glaciation, as Kentucky used to look like Canada. Analysis of pollen in sediment cores taken from natural ponds in Kentucky confirms this, spruce and jack pine was common in the uplands in the bluegrass. Sometimes it is difficult to think of plants migrating north and south in order to adapt to a changing climate. But what is even more mind blowing is that the genus Comptonia is perhaps millions of years old. Numerous fossils of dozens of extinct species of Comptonia have been found all across the Northern hemisphere, and the earliest of the fossils have been dated back to the Cretaceous period (the age of the Dinosaurs) over 65 million years ago. The first flowering plants (angiosperms) evolved only 135 million years ago, so Comptonia is one of the oldest living plants in the world—a true living fossil!

So when April comes around, and all of the spring wildflowers are emerging, think of sweet fern tucked deep into the gorges of Big South Fork and Rockcastle, its catkins releasing pollen in the wind, using the nitrogen fixed from its bacterial friends, withstanding the massive floods of two of Kentucky’s last wild rivers. And if you use your imagination, you may be able to see dinosaurs and tree ferns in the distance.

1. Berry, Edward W. 1906. Living and Fossil Species of Comptonia. The American Naturalist. Vol. 40, No. 475, pp. 485-524.
2. Darlington, Emlen. 1948. Notes on some North American Lepidoptera reared on Sweet Fern (Compontia asplenifolia Linnaeus) with Description of new species. Transactions of the American Entomological Society (1890-). Vol. 74, No. 3, pp. 173-185.
3. Liag, X., Wilde, V., Ferguon, D., Kvacek, Z, Ablaev, A., Wang, Y., and Li, C. 2010. Comptonia naumannii (Myricaceae) from the early Miocene of Weichang, China, and the paleobiogeographical implication of the genus. Review of Paleobotany and Palynology. Vol. 163, p. 52-63.
4. Medley, Max and Eugene Wofford. 1980. Thuja occidentalis L. and other noteworthy collections from the Big South Fork of the Cumberland River in McCreary County, Kentucky. Castanea. Vol. 45, No. 3, pp. 213-215.
5. Natureserve Explorer, 2010.
   https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.134920/Comptonia_peregrina
6. Wilkins, Gary, Delcourt, Paul, Delcourt, Hazel, Harrison, Frederick, and Turner, Manson. 1991. Paleoecology of central Kentucky sicne the last glacial maximum. Quaternary Research. Vol. 36, Issue 2.
7. Virginia Tech Woody Database
   http://dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=869
8. Zomlefer, W. 1994. Guide to Flowering Plant Families. University of NC Press, Chapel Hill.

The Lady Slipper newsletter of the Kentucky Native Plant Society has been published since the Society’s founding in 1986. This is one of a series of reprints from past issues. This article, about North America’s largest native fruit, the pawpaw (Asimina triloba), found in every county of KY, first appeared in the fall of 2005, Vol. 20, No. 3. If you would like to see other past issues, visit the Lady Slipper Archives, where all issues from Vol. 1, No. 1, February 1986 to Vol. 34, No. 1, Winter/Spring 2019 (after which we moved to this blog format) can be found.

The author, John Thieret, left a huge legacy to the native plant community when he passed in 2005. “Kentucky has lost its most renowned American plant taxonomist of the 20th century. John W. Thieret, Professor Emeritus of Biological Sciences at Northern Kentucky University, retired Director of the Northern Kentucky University Herbarium, Associate Editor of Sida, Contributions to Botany, and Editor of the Journal of the Kentucky Academy of Science (JKAS) passed away on 7 December 2005, at Alexandria, Kentucky.”

To learn more about this giant of Kentucky Botany, read the articles and tributes to him in the Winter 2005/Spring 2006, Vol. 20, No. 1, of the Lady Slipper archives.

Kentucky’s ‘Tropical’ Fruit,
the Papaw

by John Thieret, NKU

A visit to a fruit/ vegetable market in the tropics is a great experience. All sorts of plant products that we in the temperate zones do not recognize are there. Among these are fruits of the Annonaceae, the custard-apple family, including the bullock’s-heart, cherimoya, guanabana, sweetsop, and soursop. These are unknown to most people in our part of the world, but we do have a member of the Annonaceae that does NOT grow in the tropics, our papaw, Asimina triloba. This is a shrub or small tree, which, as I have seen it, never exceeds perhaps 20 feet in height and 6 inches in trunk diameter, although there are reports of individuals 50 feet tall and with a trunk 2 feet in diameter, truly a mega-papaw.

A common enough plant, the papaw thrives in rich woods over much of eastern U.S. from northern Florida to far eastern Texas, then north to New York, far southern Ontario, Michigan, Iowa, and southeastern Nebraska. It grows throughout Kentucky, almost certainly in every county.

Although some papaw enthusiasts wax ecstatic over the fruits, papaws are not everyone’s favorite. This divergence in appreciation stems from, first, natural differences in fruits from different trees and, second, differences in people’s taste buds. I have found fruits from some trees not worth the effort of trying to get them down from the branches. But other trees can produce fruits that I’d describe as almost excellent. The best papaws I ever tasted were in southern Illinois on a rather cool, almost frosty fall morning. Yes, quite worthwhile. The Indiana poet James Whitcomb Riley described, in hoosier dialect, the gustatory experience:

And sich pop-paws! Lumps a’ raw
Gold and green,—jes’ oozy th’ough
With ripe yaller—like you’ve saw
Custard-pie with no crust to.

Another assessment of the taste, by an Indiana lad, is included in Euell Gibbons’ book Stalking the Wild Asparagus: “They taste like mixed bananers and pears, and feel like sweet pertaters in your mouth.” I’ll second that, at least for a good papaw.

Long before Europeans began their assault on the North American continent,the indigenous peoples, along with various animals—possums, raccoons, squirrels, and skunks—sought the fruit. The first Europeans to see it—some 450 years ago—were De Soto and his entourage. They wrote of it, mentioning its “very good smell and excellent taste.” About 200 years later the plant was introduced into cultivation by Europeans who brought seeds to England. Then in1754 the first illustration of the papaw appeared in Catesby’s Natural History of Carolinas (see right). Lewis and Clark, in the early 19thcentury, found the fruits to be welcome additions to a meagre diet. To this day, the fruits are collected and used by country people and by city dwellers who like to eat their way through the landscape.

As for ways to use the fruits, first and foremost they can be eaten out of hand. As they ripen, they change from green to brown or nearly black, then looking not especially appetizing (recalling ripe plantains). The fruit pulp, creamy and sweet, contains several large,flattened, brown seeds. One of my friends made a necklace for his wife from the seeds. Better, I guess,than one made from finger bones.

Enthusiasts use the fruit for pies, puddings,marmalade, bread, beer, and brandy. I’ve tasted papaw bread and found it OK. Barely. I once tried to make papaw bread—I’ll say no more about that dismal experience. (The persimmon bread I attempted was no better.)

On a few occasions I have seen the plant grown as an ornamental. With its large, somewhat drooping leaves, it is rather attractive. The maroon flowers,which bloom in spring when the leaves are still young and covered with rusty down, are not all that conspicuous, and the fruits—well, my experience has been that papaw plants in cultivation as lawn specimens just do not make many fruits. As a matter of a fact, I have always noted that, even in the wild,the fruits are not abundantly produced. Maybe I just was not at the right place at the right time. The plants seem to require cross pollination, which is a disadvantage to those who would use them as ornamentals and, at the same time, would like some fruits.

If you have never tried one of the fruits, head for the woods in the autumn and attempt to find one. Maybe someone you know can help you. Even if you do not find the fruit much to your liking—maybe you will,maybe you won’t—you will have had a new gustatory experience.

For many years attempts have been made by horticulturists to ‘improve’ the papaw and make it into a commercially viable fruit. Their efforts notwithstanding, the fruit remains a Cinderella. On only one occasion have I seen papaws for sale: at a roadside farmer’s stand in southwestern Ohio among a fine display of squashes of a dozen kinds. Breeding and selection work has been carried out in several places, notably at Kentucky State University where about 1700 papaw trees grow in KSU’s 8-acre experimental farm and where the PawPaw Foundation is headquartered. Once, in Pennsylvania, I saw a papaw orchard of maybe 50 trees. I wish now that I had stopped and spoken with the orchard’s owner.Perhaps, with continued efforts at breeding and selection, papaws might some day be common items in our temperate fruit and vegetable markets, as common even as are the annonaceous cousins of Asimina triloba in markets of the tropics. This is the goal toward which papaw enthusiasts and breeders are striving.

The Lady Slipper newsletter of the Kentucky Native Plant Society has been published since the Society’s founding in 1986. This is one of a series of reprints from past issues. This article, about one of Kentucky’s loveliest goldenrods, first appeared in the spring of 2005, Vol. 20, No. 1. If you would like to see other past issues, visit the Lady Slipper Archives, where all issues from Vol. 1, No. 1, February 1986 to Vol. 34, No. 1, Winter/Spring 2019 (after which we moved to this blog format) can be found.

The author, Mary Carol Cooper, left a huge legacy to the native plant community when she passed in 2016. In almost every native plant gathering, her name is mentioned and a moment is given over to appreciate her knowledge, which she freely shared. Her passion led many of us to our love of natives; she was a mentor and friend to many of us.

2005 Wildflower of the Year
SHOWY GOLDENROD (Solidago speciosa)

By Mary Carol Cooper
Salato Native Plant Program Coordinator
Salato Wildlife Education Center

Wildflower enthusiasts from all across the state have selected Showy Goldenrod (Solidago speciosa) as the Salato Native Plant Program’s Wildflower of the Year for 2005. The Wildflower of the Year is chosen based on the number of nominations it receives and how well it fits the established criteria; must be native to Kentucky, common and widespread across the state, seeds must be readily available, must be easy to grow, and must have good wildlife value.

Showy Goldenrod is a hardy perennial that grows 2 to 6 feet tall, depending on where it is planted. It is a rather showy species with stout, smooth, reddish stems and smooth, deep green leaves that are 4 to 10 inches and not toothed. It grows in rich thickets, woodland openings, fields, and prairies. It likes average to well drained soil and grows in sun to partial sun. It has dense upright pyramidal flower clusters. Each flower head has 6 to 8 rays. Showy Goldenrod blooms in late in the summer (August to September) and is wonderful as a late summer nectaring source for bees, butterflies and hummingbirds. It also provides food for several species of songbirds such as the Goldfinch, Junco, Pine Siskin, Song and Tree Sparrows.

Goldenrods are insect pollinated and their pollen is heavy and sticky. Therefore their pollen is never in the wind, so contrary to popular belief, this is not the plant that has always been blamed for causing hay fever. It is ragweed that causes all the misery! Ragweed blooms at the same time and is wind pollinated. I’ve enjoyed watching more and more floral designers use goldenrods in their arrangements and wonder how many people are aware that their lovely bouquet is full of the “dreaded goldenrod”.

Goldenrod is truly a North American flower. There are approximately 125 species in North America and more than 30 of these are native to Kentucky. Since the State Flower is Solidago ssp. this must mean that we have 30 State Flowers! Two of out native goldenrods, White-Haired Goldenrod and Short’s Goldenrod are on the Federally endangered species list.

Showy Goldenrod makes a nice background or midground plant in a sunny perennial garden. Establish this plant at the very rear of the garden or in the very middle of a circular or oval garden. Allow 3 feet between plants as this species grows into large clumps very fast. They can be divided every year or so and given to friends and neighbors. Nice companion plants are Ironweed, Great Blue Lobelia and New England Aster. Plants naturalize quickly on dry sunny banks. The cuttings are outstanding in arrangements.

The genus name Solidago comes from the Latin word that means “to make whole” or “to heal”, a name chosen because of medicinal power the plant was believed to have. The Native Americans used this plant for many things including ridding people from pain and evil spirits. One Goldenrod superstition says that he who carries the plant will find treasure, therefore, Goldenrod is the symbol for treasure and good fortune.

Goldenrod seeds and plants are available from many native plant nurseries. It is also very easy to propagate either by seeds, or division. Sow seeds thickly in outdoor seedbeds early in the fall or sow stored seed later in a flat indoors or in a cold frame. Transplant when there are 3 to 4 leaves. When the roots fill the pot, transplant in the garden after the last frost date. Collect seeds in late September or October. Cut off seed heads and put them upside down in a large paper bag. Let them dry for up to a week and then shake them in the bag and put the seeds in a sealed container.