The Office of Kentucky Nature Preserves (KNP) is currently working on a restoration project in southern Cumberland Plateau of Kentucky. The preserve in which the project is located is home to one of the largest populations of the federally threatened white-fringeless orchid (Platanthera integrilabia) in Kentucky. This elusive orchid, also known as monkey-faced orchid, is a beautiful two-foot tall plant with white flowers blooming in late summer. Over a decade ago, the restoration project was initiated to boost population numbers of the orchid as it was experiencing detrimental population losses. As the project progressed, it transitioned into the restoration of the entire plant community, a Cumberland Plateau acid seep, in which the white-fringeless orchid grows.
A Cumberland Plateau acid seep in itself is a rarity across Kentucky’s landscape. These acid seeps occur in the headwaters of streams in eastern Kentucky on the Cumberland Plateau. They are transient wetland communities that change over time through the creation of canopy gaps in a forest and the subsequent closing in of the canopy. Historically, these canopy gaps were thought to be the result of natural old-growth tree falls, megafaunal disturbance, flooding and periodic fires. The canopy gaps created from the natural tree falls resulted in a depression in the soil and an increase in solar exposure to the ground. Flooding events would fill in the depression with water and a different suite of plant species were able to come in and thrive. Periodic fire and animal browsing helped to maintain these wetlands as open by keeping woody plants from growing and re-closing the canopy.
Grass Pink (Calopogon tuberosus)
As a direct result of logging and fire suppression, acid seeps disappeared from the landscape. The remaining pockets of these communities in Kentucky are often associated with rare plants as the suite of species that grow there can be limited to this unique habitat type. Habitat loss is the biggest threat to the white-fringeless orchid. Other plants associated with acid seeps include white turtlehead (Chelone glabra), red chokeberry (Aronia arbutifolia), grass pink (Calopogon tuberosus), sedges (Carex spp.), regal fern (Osmunda regalis), cinnamon fern (Osmundastrum cinnamomea), club-spur orchid (Platanthera clavellata), yellow-fringed orchid (P. ciliaris), crested yellow orchid (P. cristata), peat moss (Sphagnum spp.), and netted chainfern (Woodwardia areolata).
The ideal habitat for white-fringeless orchid is not entirely known to scientists as there are many factors involved (hydrology, solar exposure, pollinators, plant associates, etc.). For the past 13 years, KNP botanist Tara Littlefield has been collecting data on this population of white-fringeless orchid to track the progress of the restoration project, as well as glean information about what makes an ideal white-fringeless orchid habitat. This research has led to a better understanding of the seep hydrology, orchid population trends, as well as pollinator dynamics.
KNP determined the best method to save the white-fringeless orchids was to recreate its ideal habitat. To restore the acid seeps, KNP land managers have maintained them in a static state of open canopy rather than letting the canopy naturally close over time. They have maintained the seeps in this way by thinning the canopy and understory through intensive manual removal of woody and invasive species from the interior and fringes of the seeps. In the coming years, prescribed fire will also be utilized once the effects of the fire on the orchid are better understood. These methods have allowed KNP to achieve their goal of increasing the orchid population numbers.
Now that the Cumberland Plateau acid seeps are in better conditions, KNP’s restoration project has once again evolved and expanded to include the uplands adjacent to the seeps. These uplands are heavily forested with low plant diversity and the management goal is to restore them to Cumberland Plateau pine-oak barrens, another rare plant community in decline in eastern Kentucky. Pine Barrens are open woodlands made up of a mix of sandstone outcrops, grasslands, and open pine-oak woodlands with an open understory.
Wood lily (Lilium philadelphicum)
Historically, pine barrens were maintained by periodic fire keeping the understory and canopy open. Due to logging and fire suppression, this community is greatly reduced and altered in Kentucky. The majority of the remnant pine barrens in Kentucky are restricted to powerline corridors and roadsides in the Daniel Boone National Forest (DBNF). Consequently, many of the plants once associated with this plant community are also rare. Wood lily (Lilium philadelphicum) for example, is restricted to this habitat in Kentucky and can be found primarily on roadsides of the DBNF. Population numbers of wood lily have plummeted in recent decades. Numerous other plants of concern also depend on this habitat including Ten-lobed False Foxglove (Agalinis decemloba), Yellow Wild Indigo (Baptisia tinctoria), Bearded Skeleton-grass (Gymnopogon ambiguous), Southern Crabapple (Malus angustifolia), Appalachian sandwort (Minuartia glabra), Racemed Milkwort (Polygala polygama), Hairy Snoutbean (Rhynchosia tomentosa), Chaffseed (Schwalbea americana), Eastern Silvery Aster (Symphyotrichum concolor), and Roundleaf Flameflower (Talinum teretifolium).
Currently, KNP land managers are restoring the uplands to pine barrens by thinning out softwood trees, such as black gum and maple, and leaving hardwood trees, such as shortleaf pine and oaks. They have left a buffer of forests around the white-fringeless orchid seeps until there is a better understanding of how the orchids will react to periodic fire. Prescribed fire will be utilized in coming years to maintain the woodlands in an open state and help rejuvenate the grasslands. Josh Lillpop, KNP Natural Areas Branch Manager, said of the project, “so much of what we are trying to do right now is related to increasing the sunlight on the forest floor. We have already seen some interesting things showing up where canopy gaps have been created.” In the future, they may be able to reintroduce some of the rare plants, such as wood lily, to these pine barrens where they can thrive.
KNP’s restoration project has changed from a single species focus to overhauling an entire ecosystem in eastern Kentucky. Littlefield said of the project, “it’s important to protect this federally threatened plant, but it also led us down this path of restoring all of these rare ecosystems that are interconnected in the Cumberland Plateau. We’re hoping to eventually connect the pine barrens project to the seep project as we learn more about the fire effects and get a handle on the invasive species.”
Earlier this year, I was working on a project surveying for rare plants and natural communities in the Big South Fork of Kentucky. Hidden in the biologically diverse region of the Cumberland Plateau, we share this region with Tennessee, where headwater streams flow north into Kentucky and create river scour communities along the Big South Fork of the Cumberland River. The Big South Fork is by far one of my favorite places on Earth. The diversity of species, both plants and animals, even undescribed taxon, is astounding. And the river scour communities within this region contain more globally rare plants than anywhere else in Kentucky! This species diversity is only compounded by the complexity of the riparian communities from emergent marshes, outcrops, grasslands, shrublands and woodlands that are maintained by the wild river scour. It’s one of the few places still left in Kentucky where pre-settlement natural conditions still exist, it’s as if you are seeing a landscape that was seen by Native Americans, a true wilderness. And this is also one of our states largest intact forest blocks. It feels ancient, diverse and wise.
Devils Jump , Big South Fork, Kentucky
A tale of Large flowered Barbara’s Button’s
Joining me on the Cumberland Plateau river scour botanical survey team this year were Kentucky Nature Preserves botanists Heidi Braunreiter and Devin Rodgers. This past May 2019, one of our main target species was Barbara’s buttons (Marshallia grandiflora), an elusive rare plant tucked away behind large boulders and cobble on the river scour of the Big South Fork. Marshallia is a genus in the aster family, and all the species within this genus occur in the southeastern United States. Marshalllia grandiflora is endemic to the Appalachians and the Cumberland Plateau, and is currently being assessed for federal listing. It is endangered in Kentucky and Pennsylvania, and threatened in Tennessee and West Virginia, and extinct in North Carolina. The habitat consists of diverse prairioid grasslands that occur on the river scour of several wild rivers. Associated plants of Marshallia consist of species you would find in a prairie such as big blue stem (Andropogon gerardii), Indian grass (Sorgastrum nutans), wild blue indigo (Baptisia australis), blazing stars (Liatris microcephala), sunflowers (Helianthus giganteus, H. hirsutus, H. decapetalus), tall coreopsis (Coreopsis tripteris), st. johns worts (Hypericum sp.), Obedient plant (Physostegia virginiana), goldenrods (Solidago sp.) and asters (Symphytrichum sp.).
large flowered Barbara’s buttons (Marshallia grandiflora)
Large flowered Barbara’s buttons (Marshallia grandiflora)
small blazing star (Liatris microcephella)
wild blue indigo (Baptisia australis)
wild potato vine (Ipomoea pandurata)
obedient plant (Physostegia virginica)
sensitive plant (Mimosa microphylla)
Large flowered Barbara’s buttons are very rare. In Kentucky, at the northern edge of its range in the Cumberland Plateau, this plant is extremely endangered and declining. When we were lucky enough to find a population, only a few single flowers or rosettes had survived. Many questions remain unanswered about this plants life cycle on the Big South Fork of the Cumberland River. How does this perennial stay rooted in the floods? How would seed produced ever have the chance to germinate? I would imagine a deep tap root or an abundance of lateral roots to anchor this plant during the floods, and an ability to live a long life (maybe even thousands of years old), but we just don’t know. And the mammal or bird dispersed seed taking root in the dry months of the summer, quickly sending its taproot to prevent it from being washed away in the next flood. Could a plant’s root break off during a flood, travel downstream and re root in suitable habitat, essentially replanting itself through vegetative reproduction? This is strategy is employed by the Cumberland rosemary (Conradina verticillata), but it is unclear weather Marshallia is able to do this. But a shift in flooding patterns, and changing climate, bring uncertainty and could prevent a seedling from taking hold. There are so many unknowns and confounding factors in the life cycle of this plant.
Large flowered Barbara’s buttons (Marshallia grandiflora)
Life on the river scour can be harsh. Brutal even. For both its inhabitants as well as surveyors like ourselves. There are copperheads and rattlesnakes hiding within these prairies, with massive boulders and logjams slowing our travel. Bouldering and rock hopping is necessary to navigate the jumbled debris. With the rains come floods that roar through the gorge, scouring everything in its path. It’s amazing to me that anything can survive that. But it is this very disturbance that maintains these “prairies of the river,” for without the flooding and scour, shrubs and trees would take hold and the prairie grasses and forbs would disappear. Couple this flooding with summer droughts to keep the trees and shrubs at bay, and the river prairies thrive. Dam these rivers and everything disappears.
Braunreiter and Littlefield crossing the Big South Fork
Rodgers exploring the large boulders of the river scour
Little is known about how long these plants have been hiding out amongst the boulders of the river scour. Likely these disjunct populations from Pennsylvania to Tennessee were connected in the ancient Appalachian landscape. Probably they were more common, and may have evolved within a much more expansive upland ancient prairie habitat that has long ago vanished due to natural large scale climate change, as well as a more connected river scour habitat that is now nearly lost due to damming of rivers and degradation of plant communities from invasive plants, loss and alteration of disturbance regime, and a changing climate. There is even new research into the genetic differences among the extinct North Carolina populations with the rest of the population range, suggesting that there are two different species uniquely evolved in isolation. So what is our role in conserving this unique species? One can only speculate that this species is an ancient plant of a lost world, perhaps evolved in in the ancient upland grassland habitat, but now only found in sheltered ravines codependent on the floods of our protected wild rivers to maintain its habitat and ensure its further existence.
Large flowered barbara’s buttons (Marshallia grandflora)
Other interesting rare plants that we encountered on the river scour this year include the globally rare Rockcastle aster (Eurybia saxicastellii), Balsam ragwort (Packera paupercula var. paupercula), Turk’s-cap lily (Lilium superbum), golden club (Orontium aquaticum), the federally threatened Cumberland rosemary (Conradina verticillata) and the boulder bar goldenrod (Solidago racemosa). Included in the mix are intriguing mysteries of possible news species. But there is one rare plant that we encountered on the river scour that has always intrigued me by its glacial relict past, as it seemed to tell the story of these lost worlds with more clarity, of large scale plant migrations over spatial time that us humans can only begin to comprehend, the sweet fern (Comptonia perergina).
Rockcastle Aster (Eurybia saxicastellii)
Turk’s cap lily (Lilium superbum)
Cumberland rosemary (Conradina verticillata)
Balsam ragwort (Packera paupercula var. paupercula)
Sweet Fern-an ancient glacial relict plant lost in the
south
The wax myrtle or bayberry family
(Myricaceae) is known for its odor. These
plants have resinous dots on their leaves, making them aromatic. Plants in this family have a wide
distribution, including Africa, Asia, Europe, North America and South America,
missing only from Australia. Myricaceae
members are mostly shrubs to small trees and often grow in xeric to swampy
acidic soils. 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 place does this
interesting family have in Kentucky’s flora?
We are lucky to have one species in the wax myrtle family, sweet fern (Comptonia peregrina). In addition, it is also a monotypic genus
restricted to eastern North America meaning the genus Comptonia has only one species (C.
peregrina) worldwide, and we are lucky it is found here in Kentucky!
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. But having sweet in the common name is no
mistake. If you crush the leaves, 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 occur on different plants. The female flowers are not showy—short
rounded catkins that are 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 with small corky pores or narrow lines on the bark that allow for
gas exchange.
Sweet fern catkins on the Big South Fork
Sweet fern (Comptonia peregrina)
While 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 in Ohio, 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 that followed glacial cycles.
Sweet fern (Compotonia peregrina) range
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 on the sandstone cobble bars
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 ancient plant. In
Kentucky, it was likely more common 20,000 years ago during the last glacial
period, as Kentucky’s climate was much more like present day Canada. Analysis of pollen in sediment cores taken
from natural ponds in Kentucky confirms that spruce and jack pine was common in
the uplands in the bluegrass. Sometimes
it is difficult to imagine 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 at least 65 million 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 during the
age of the dinosaurs. The first flowering plants evolved only 135 million years
ago, making Comptonia is one of the
oldest living plants in the world—a true living fossil!
When April 2020 comes around,
and all of the spring wildflowers are emerging, think of sweet fern tucked deep
into the gorges of Big South Fork, its catkins releasing pollen in the wind, think
of Barbara’s buttons withstanding the massive seasonal floods of one of Kentucky’s
last wild rivers. And if you use your
imagination, you may be also be able to see dinosaurs and tree ferns in the
distance. Let us hope sweet fern and Barbara’s buttons
can survive for many millions of years to come.
The Lady Slipper, the newsletter of the Kentucky Native Plant Society, has been published since 1986 (see all back issues here). Published three to four times a year, The Lady Slipper contains a mix of news, upcoming events, and articles about the native plants of Kentucky.
With this issue (Vol. 34, No. 2, Summer/Fall 2019) we are changing the format of The Lady Slipper, to a blog format on our website
We are in need of someone willing to take on the job of Editor. The editor solicits and collects articles for each issue. The articles are put into the WordPress blogging platform and then formatted and edited. Experience with WordPress would be great, but even if you are not familiar with WordPress, the Society’s webmaster can help you quickly come up to speed.
If you love native plants and like to edit and organize articles, we would love to have you on the team. If you have any questions or have an interest in helping out, just email KYPlants@knps.org
Kentucky Native Plant Society is looking for your help to assist with monitoring Cumberland Plateau pine barrens remnants along roadsides and powerlines in the Daniel Boone National Forests (DBNF). This is a rare plant community in eastern Kentucky. Pine Barrens are open woodlands made up of a mix of sandstone outcrops, grasslands, and open pine-oak woodlands with an open understory. Historically, pine barrens were maintained by periodic fire keeping the understory and canopy open. Due to logging and fire suppression, this community is greatly reduced and altered in Kentucky. The majority of the remnant pine barrens in Kentucky are restricted to powerline corridors and roadsides in the DBNF. Consequently, many of the plants once associated with this plant community are also rare. Wood lily (Lilium philadelphicum) for example, is restricted to this habitat in Kentucky and can be found primarily on roadsides of the DBNF. Population numbers of wood lily have plummeted in recent decades. Numerous other plants of concern also depend on this habitat including Ten-lobed False Foxglove (Agalinis decemloba), Yellow Wild Indigo (Baptisia tinctoria), Bearded Skeleton-grass (Gymnopogon ambiguous), Southern Crabapple (Malus angustifolia), Appalachian sandwort (Minuartia glabra), Racemed Milkwort (Polygala polygama), Hairy Snoutbean (Rhynchosia tomentosa), Chaffseed (Schwalbea americana), Eastern Silvery Aster (Symphyotrichum concolor), and Roundleaf Flameflower (Talinum teretifolium).
Knowing where plants occur is the first step towards protecting them. If you wish to help, please fill out this Signup Form and we will give you a section of DBNF roadside/powerlines to monitor over the coming growing season. We will utilize the smartphone app iNaturalist as a means of documenting the rare plants you find.
The
app iNaturalist has grown from a graduate project at U.C. Berkeley to
a global community of naturalists looking to connect people and
nature through technology. The goal of the app is to allow citizens
scientists, like yourself, to record biodiversity. Photographs taken
with your smartphone are uploaded to the app, along with location
data, where naturalists from across the world help identify the
organism. By posting your photographs, you can contribute to a better
understanding of the range and abundance of plants and animals.
Kentucky Native Plant Society will track your photographs of plants
along DBNF roadsides in an effort to protect these rare plants and
remnant ecosystems. Hopefully, these efforts will go a long way
towards protecting the Cumberland Plateau pine barrens remnants and
the rare plants associated with them.
Citizen Scientists contribute to continental scale study to assess variation in nitrogen use of red maple (Acer rubrum)
By: Steve Gougherty* * PhD Student, Finzi Lab, Department of Biology, Boston University
Nitrogen dynamics in plants
In
terrestrial ecosystems, plant growth is commonly limited by the
availability of nitrogen. Nitrogen is a critical element for plant
health as it is incorporated into key molecular structures such as
chlorophyll, which absorbs light energy during photosynthesis, and
enzymes (e.g., RuBisCo, which is responsible for fixing carbon
dioxide from the atmosphere as part of photosynthesis). Many plants
start life with a nitrogen reserve in their seeds, but eventually
come to rely on their root system to absorb nitrogen from the soil to
satisfy their demand.
Acquiring
nitrogen from soil can be a costly endeavor for plants, and perennial
plants have developed strategies to more efficiently use the nitrogen
they have already acquired. For example, deciduous trees effectively
recycle nitrogen at the end of each growing season through a process
known as foliar nitrogen resorption. Foliar nitrogen resorption
involves the breakdown of nitrogen containing compounds (like
chlorophyll and enzymes) in the leaf and the transfer to other
tissues in the plant, such as developing buds. In fact, the breakdown
of chlorophyll in leaves and transfer to other plant tissues is
partially responsible for the ‘fall colors’ in eastern temperate
forests. Even though researchers know that foliar nutrient resorption
is an important component of tree’s annual nitrogen budget,
extremely little is known about how variable this process is
throughout geographic ranges of plants. This is an important question
because understanding the nature of nitrogen limitation on plant
productivity is an active area for ecologists studying energy and
carbon balances of ecosystems.
Citizen Scientist role in addressing questions about red maple nitrogen use
Red maple
(Acer rubrum)
is one of the most abundant and broadly distributed tree species in
North America (Figure 1; green shading shows approximate
distribution). Its abundance and broad distribution makes it an
excellent candidate to assess the potential for variation in key
nutrient retention strategies, such as foliar nitrogen resorption.
However, sampling red maple throughout its geographic range is a
major logistical challenge for an individual researcher. As a result,
I started a Citizen Science project that invites participants to
sample red maple leaves in their local areas and send them to a
research laboratory for processing and analysis. A broad network of
Citizen Scientists is ideal for this project for several reasons: 1.
Citizen Scientists know where to find red maple trees in their local
areas. 2. The network allows for the potential to obtain samples from
nearly the entire geographic distribution of red maple in the United
States. 3. Since Citizen Scientists sample locally, it makes the two
sampling time points (once when leaves are green, and once at leaf
fall) feasible.
2019 was the initial year of the project and over 120 Citizen Scientists signed up to participate in the project (Figure 1; magenta dots). As leader of this project I am extremely grateful for the response we have received and look forward to disseminating our results to our Citizen Scientists and the scientific community over the course of the project. Participants interested in collecting in 2020 are welcome to sign up on our website at any time.
Getting involved in the project
Interested members of the Kentucky Native Plant Society and readers of The Lady Slipper are invited to learn more about the project at our website: sites.bu.edu/tasper . On our website we have more information about our research questions along with a signup form for participants, and sampling protocols.
THE GENUS AGASTACHE IN KENTUCKY (Clayton – 1830’s ex Gronov. 1762)
Also known as Giant Hyssops or Hummingbird Mints has two native species in Kentucky: Agastache nepetoides (L.)-Kuntze (1891) Catnip/Yellow Giant Hyssop and Agastache scrophulariifolia (Willd.)- Kuntze (1891) Purple Giant Hyssop.
The genus Agastache is in the Lamiaceae (mint) family, subfamily nepetoideae, and the tribe mentheae. This genus was formally established in 1762 by a Dutch botanist Jan Frederik Gronovius (1690-1762) in his second edition of Flora Virginica (Linnaeus actively assisted Gronovius with this work). Flora Virginica was actually based on the notes and specimens sent to Gronovius by an English botanist John Clayton (1695-1773) while he was living in Virginia. Clayton had given the genus name to these perennial flowering herbs in the 1730’s. The second edition was published in 1762 by Grovonius’ son, Laurens (also a botanist), as the elder Grovonius had died in June of 1762. This second edition was published without Clayton’s knowledge or permission. Agastache’s author’s citation is often followed by Clayton ex Grovonius (Gronov.). Linnaeus named a genus of wildflowers – Claytonia (Spring Beauty) in honor of Clayton’s botanical contributions. Agastache (many spikes) comes from the Greek word Agan (many/very much) and Stakus/Stachys (ears /spikes of grain/wheat) which describes the plant’s “many ears/spikes” of inflorescences.
Agastache plants are aromatic flowering perennials with 21 species in North America and 1 specie in Eastern Asia. The erect/branching mint family plants range from 0.5m tall to 3m tall with square stems and opposite, petioled, coarsely toothed leaves 1-15cm wide. Aromatic inflorescences of upright spikes 2.5-15cm long resemble candles in a candlelabrum. Numerous flowers per spike are 0.6cm long. Five petals/sepals (tepals) form a tubular two-lipped flower with 2 lobes on the upper lip and 3 lobes on the lower lip. Four stamens extend beyond the flower – 2 upper stamens curve downward and 2 lower stamens curve upward. Fruit is a brown round/oval dry nutlet 1.5-2mm long with minute hairs at the squared tipped end. Flowers, which do not open at the same time, can be white, yellow, orange, red, magenta, pink, mauve, blue purple, or lavender. Plants generally thrive in moist (not wet), sun or shade, rich soil, and limestone based anthropogenic (man-made/disturbed), forest edges, talus, and rocky habitats. They are hardy in zones 3-6. Agastaches are believed to be descended from robust aromatic Asian plants which are in the Genera Dracocephalum (typical dragonheads), Lallemantia (West Asian dragonheads), Shizonepeta (Japanese catnip), and Hyssops (True hyssops). The Agastaches probably/are believed to have originated as a North American/Trans-Beringian (Laurasion distribution) offshoot about 25 million years ago (late Oligocene geologic epoch of late Paleogenic period). Debate is on-going as to Agastache lineage.
The common name, Hummingbird Mint, is from the Agastache flowers’ attraction to hummingbirds and the mint/anise aromas of their leaves. The common name, Giant Hyssop, is fairly ambiguous. Hyssop is both the classic name for genus Hyssopus and the plant Hyssopus officinalis (Hyssop) coined by Lineaus in 1753. Hyssop is a Eurasian (southern Europe/western Asian) aromatic mint with 4 stamens, square stems, and narrow/lanceolate opposite leaves. Hyssop can be used as an adjective to describe leaves that tend to be narrow/oblong/lanceolate – as Eupatorium hyssopifolium – commonly known Hyssop Leaf Eupatorium or Thoroughwort. Interestingly, Hyssop or a “Hyssop-like” plant is mentioned in the Bible – 10 times in the New Testament and 2 times in the Old Testament. The Hebrews identified the plant as Ezov or Ezob while the Greek translation of this plant was Hyssop. Both the Hebrew and Greek name of this plant mentioned in the Bible probably share a common but unknown origin. Hyssopus officinalis (Hyssop)(L.) is not the Hyssop mentioned in the Bible as it is a southern European/western Asian species and was unknown in Palestine at these earlier biblical dates. Biblical scholars cite Origanum syriacum (Syrian Hyssop), a close relative to oregano and majoram, as most likely the Hyssop mentioned in the Bible. Other scholars believe that a mustard plant, caper (Capparis spinosa), or a mint family plant (Origanum maru), is the Biblical Hyssop. The issue is not resolved as to the actual identity of the “hissop” so important to Hebrew purification rites. Why Linnaeus chose Hyssopus (hyssop) for the genus name of these earlier mints now in the Agastache genus was probably based on several botanical/taxonomy factors of that time (plant structure, appearance, and sex organ(s) composition).
There are two native species of Agastache in Kentucky: A. nepetoides (L.) 1753-Kuntze (1891), Yellow Giant Hyssop and A. scrophulariifolia Willd. (1801)-Kuntze (1891), Purple Giant Hyssop. Agastache nepetoides is an infrequent FACU (Facultative Upland) plant found occasionally in wetlands (1-33%) and dry to mesic open woods and woodland borders across Kentucky. Greenish-yellow flowers are present (see photos). Agastache scrophulariifolia is a rare historical (not observed since 1980) plant in the Appalachian plateaus and interior low plateaus. Flower colorations range from white to blue/purple (see photes). Both these mint family plants have square stems, opposite leaves, and are aromatic. Both bloom July through October and stalks can remain standing through the winter. Flower colors are yellow for A. nepetoides and mainly blue/purple flowers for A. scrophulariifolia. Flower colorization can readily distinguish these two species. Other subjective differences can/may also assist in the identities:
A. nepetoides – Yellow Giant Hyssop 2-5 feet tall square stems – may be slightly winged smooth stem weakly aromatic calyx – 1-1.5 mm with ovate lobes
A. nepetoides – Yellow Giant Hyssop
A. scrophulariifolia – Purple Giant Hyssop 3-6+ feet tall no winged stems minute hairs on stem strongly aromatic calyx – 2-2.5 mm – with lanceolate lobes
A. scrophulariifolia – Purple Giant Hyssop
Agasstache nepetoides has other common names: catmint, catnep, catnip for its aromatic scent similar to catnip (Nepeta cataria). Yellow Giant Hyssop may also be referred to as calmint/calamint for its medical usages in tea or as a conserve (undried vegetables mixed with sugar and blended to form a soft mass) for a “calming” effect in treating “hysterical” complaints, seizures, stomachaches, and colic.
The species name nepetoides (L.) Yellow Giant Hyssop is Latin based meaning resembling Nepeta (catmint). The origin of nepetoides may be from several sources. Nepeta is Latin for catnip/catmint and was used by Linnaeus in 1738 as the genus name for catnip – “nepeta floribus interrupte spicatis pedunculatis” (nepeta with flowers in a stalked interrupted spike).
An Italian city named Nepi, Nepet, or Nepete that was well-known for having a “catnip” plant with a less aromatic/enticing scent could also be the source of nepeta. Finally Nepa is Latin for a water scorpion whose sting was treated by the Yellow Giant Hyssop may also play a as the species name.
Agastache scrophulariifloria’s (Purple Giant Hyssop) other common names are Lavender Hyssop, Anise Hyssop, Prairie Hyssop, Horsemint, and one unusual moniker – Figwort/Pilewort. Figwort is from Old English words Fig meaning piles (hemorrhoids) and an Old English word wort meaning plant usually possessing medicinal usages – thus Figwort/Pilewort is a plant to treat hemorrhoids. (Several other plants may also go by Pilewort: fireweed (Erechtite hieraciifolia) and lesser celadine (Ranunculus ficaria). Purple Giant Hyssop specie’s name scrophulariifolia is from two Latin words – scrofula (meaning swelling of the lymph nodes in the neck due to tuberculosis) and folia (meaning leaves). This plant was used to treat scrofula associated with tuberculosis. Scrophularia is a genus in the family Scrophulariaceae (Figwort family with 200 species) and both are also derived from the Latin word scrofula. Interestingly both these Agastaches, Yellow and Purple Giant Hyssops, have the previous binomial genus name of hysspus – Hyssopus nepetoides (L.) (1753) and Hyssopus scrophulariifolia Willd. (1801). – (Carl Ludwig Willdenow (1765-1812), a German botanist/taxonomist – a founder of Photogeography: Study of Geographic Distributions of plants).
In 1891 Otto Kuntze, ((1843-1907) a German botanist, placed the genus Hyssopus, whose plants are called Giant Hyssops or Hummingbird mints, into the genus Agastache (Clayton ex Gronovius) probably based on Agastache leaves being more of “catnip” leaf shape, structure, and aromatic scent. Controversy still exists and with DNA sampling/testing expect more taxonomic changes.
Both the Purple and Yellow Giant Hyssops have medicinal, horticultural, culinary, and other usages that are interchangeable among the species. China has used Giant Hyssops for several centuries. With some 30+ known compounds, the Purple and Yellow Giant Hyssops have demonstrated anti-viral, anti-polio, anti-cancer, antiseptic, anti-inflammatory, antifungal, antioxidant bioactivity. Usage in AIDS and hypertension have shown promise. Ongoing research continues. Use of oils of mints in general must be used judiciously and safely – even in low doses (2-3 drops) can cause seizures and other serious complications especially in younger children. One should always consult their doctor before trying any mint oil preparation. Use during pregnancy is not advised. Native Americans used Giant Hyssops leaves and flowers in teas to treat colds, ague, fever, colic, cough, worms, rheumatism, and as an expectorant and a carmiative (anti-flatulence). They used leaves/flowers in poultices for bruises, rashes, itching, stings, swelling, and as an astringent. Native Americans used conserves for migraines, seizures, and as a “calming” agent. The Meskwaki used a Giant Hyssop infusion as a diuretic and the Iroquois/Cherokee used it for poison ivy rash and itching. Agastache scrophulariifolia specifically was used for hemorrhoids.
Culinary usages include Giant Hyssops leaves/flowers in soothing, calming, aromatic teas, as potherbs in salads, and a seasoning agent in soups/stews and other meal preparations. Seeds were made into meal. Giant Hyssop honey was viewed as a special delicious treat.
Horticultural and manufacturing usages of Giant Hyssops revolve around their economic importance. Agastache nepetoides and A. scrophulariifolia plants, seeds, rootstocks, and their cultivars are sold by nurseries and trade companies as ornamentals for landscaping, and as proven attractors for bees, butterflies, and hummingbirds so valuable for garden/crop pollination. The many pollinators are rewarded with the Hyssops rich nectar and pollen. Giant Hyssops are a favorite with beekeepers. Giant Hyssops combine/mix in nicely as companion plants to black-eyed susans (Rudbeckia), blazing stars (Liatris), and sunflowers (Heliathus). These tall beautiful native wildflowers provide valuable resources and aesthetic appeal to man and fauna.
Folklore practices concerning Giant Hyssops has dried plants hung in the home as having powers to drive out evil and negativity. Floriography has Agastache plants with symbolic meanings of cleanliness, holiness, healing powers, protection from evil, spiritual cleaning, and body-spirit protection.
Propagation of Giant Yellow and Purple Hyssops can be by seeds (after cold stratification), rhizomes, rootstocks, and spring cuttings. They can also self-pollinate which may explain their heterozygosity. Hyssops transplant readily in early stages. Seed dispersal is achieved by seed/nutlet eating birds as goldfinches, wrens, and sparrows. Wind may also disperse seeds by utilizing the hyssop seed’s hairs as airfoils or as “feathers”. Both Agastache nepetoides and scrophulariifolia are resistant to moderate drought and heat; tolerant of most soils except persistently wet habitats; and need full sun in warm climates (zones 3-6). Plants need limited competition especially from non-natives. Giant Hyssops are deer resistant and are not affected by the alleopathic capability of walnut trees. Agastaches are threatened by habitat loss, theft, extreme drought/heat, flooding, and natural succession. Giant Hyssops normally last 3-4 years.
Agastache nepetoides (Giant Yellow Hyssop) and A. scrophulariifolia (Giant Purple Hyssop) are two native Kentucky species that need our protection. These towering, robust, beautiful plants are not only aesthetic but useful to man and fauna. Look for Giant Hyssops in summer and fall. Marvel at their beauty and protect their habitats. One author caught up in Hyssops virtues/horticultural usages stated “A towering specimen in the shade garden, not for meek and mild. Do Not plant near mid/low height plants. Do plant near that jackass neighbor”!! I’ll end this paper on this whimsical thought provoking statement.
Chris Bidwell – Naturalist, past president KSNH Mary Alice Bidwell – typing Susan Wilson – photography
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