When I bought our 80-acre farm eight years ago, orchids were not on my mind.
I wanted woods to provide enough oak to warm our house during the winter and tillable
land to start a nativeplant-seed nursery. I thought orchids were plants of unspoiled wilderness,
not of old farms with overgrazed pasture, prickly ash and corn stubble.
While our home is ordinary for a small Wisconsin farm, the surrounding landscape is not.
The farm lies in the heart of the Baraboo Hills, an area known for its unique geology and
plant communities. The hills are formed by two ranges of quartzite that stood as islands in
the Cambrian Sea. Because most of the quartzite is close to the surface, much of the land
has never been plowed, making the hills home to the largest block of undeveloped hardwood
forest in the upper Midwest. The ravines or "hollows" have microclimates where species
uncommon this far south find refuge. North-facing slopes shaded by hemlock may still
harbor waterfalls of ice in May. Both Cypripedium acaule and Cypripedium pubescens grow
here, depending on the soil pH. Cypripedium pubescens is more common and favors sites
where sandstone cemented with lime overlies the quartzite. More than 6,000 acres are
protected in the hills as state parks, state natural areas, or by private conservation
groups such as The Nature Conservancy. While I expected to find orchids in these pristine
areas, I never anticipated the diversity of orchids right in our own back yard.
Our farm lies on a pocket of sandstone between outcroppings of quartzite.
Cattle and sheep grazed part of the woodland and our main pasture until 1987. On south slopes,
the dominant trees are white oak and hickory, while on north slopes sugar maple, red oak and
basswood predominate. Judging by the diameter of their trunks and their large, spreading shape,
some of the oaks are more than 150 years old and represent a remnant oak savanna.
Not quite prairie and not forest, oak savanna once covered 7 million acres in Wisconsin.
Only a small fraction remains in good condition. Most savannas have lost their open,
parklike character as invaders such as buckthorn, honeysuckle, and red cedar shade out
and kill the diversity of herbs in the understory. The oaks also decline and fail to
regenerate, since oaks are not shade tolerant. We have a mix of prairie and woodland
herbaceous species, including Asclepius purpurascens, a savanna species endangered in
Wisconsin. Fire and grazing by bison and elk once maintained our savannas. Now intensive
management is required to restore them. My wife, Martha, and I have made restoration of
our savannas our top priority, and we spend many hours cutting brush and reintroducing fire.
We find the greatest number of orchids within our savanna remnants.
Orchids Enter the Picture
The first orchid we discovered was Goodyera pubescens, the most common orchid in our area
and easily recognized by its variegated foliage. Soon after cutting brush, however,
we noticed several more species, including Galearis spectabilis, Spiranthes cernua,
Spiranthes casei, Liparis liliifolia and Liparis loeselii.
Galearis spectabilis has increased dramatically since we first noticed them five years ago.
Clones with three inflorescences now have a dozen or more. One has bloomed in full sun at the base
of our pasture following an April burn, though they are most abundant in partial shade.
Those in full shade do not bloom as often and have not increased in size. I have seen
this species most often in degraded savanna remnants on mesic soils. Perhaps its
continued presence is dependent on the maintenance of our savannas with fire and managed grazing.
While walking our pasture in midwinter, we noticed a seed capsule sticking up above the snow.
When I opened the capsule, hundreds of tiny seeds rose into the air like a vapor. I knew we
had found another orchid, but which one? The next summer we found many L. liliifolia
blooming there and elsewhere. Last July we also found L. loeselii. Why is L. loeselii,
the fen orchid, growing on a dry hillside with slopes of zero to 20 percent, sometimes in colonies
of a dozen or more? The soil is a silt loam with sandstone bedrock close to the surface.
They are most common where we cut down 20-year-old red cedars among scattered oaks.
They withstand prescribed fire and prefer open shade. This past summer a researcher
found L. loeselii growing under a clump of Sporobolus heterolepis,
a short native bunch grass, in a prairie we planted in autumn 1980 on a sandy loam
10 miles to the north. Perhaps its small size of 4 to 5 inches makes it easy to overlook in this habitat.
The showiest orchid lies just 15 feet from our fence line in our neighbor's old field,
which borders a beaver pond and creek. One day in August, I stumbled upon several Platanthera psycodes
in bloom. We have a low spot in an adjacent field which, because of the high rainfall of recent summers,
has become a wetland with bulrush and bottle gentians. I hope a few Platanthera seeds blow in and find a home there.
Propagating the Native Orchids
Finding these orchids has fueled my desire to propagate them from seed. After germinating my
first cattleya seed several years ago, I wondered why most native orchids were not available as
seedlings and collected enough information on media to start experimenting with whatever seed I could find.
When living in Maine in the mid 1980s, I tried sowing Cyp. acaule without success.
After moving back to Wisconsin, I received a permit to collect Cyp. reginae seed from a fen
owned by The Nature Conservancy. The seed germinated well on the modified Knudson's medium described
by William Ballard. When the protocorms were large enough to transfer, I compared their growth
on three different media: Ballard's, Harvais's, and Svante Malmgren's. Growth on Malmgren's medium
was so strong that I now use it for all cypripediums. It has a low salt concentration and no inorganic
nitrogen. All nitrogen comes from amino acids. Perhaps this form of nitrogen is closest to that
supplied by fungi. On this medium the roots remain a healthy white color throughout the first year.
With the help of the Wisconsin Conservation Corps, we planted two dozen Cyp. reginae seedlings
in the fen to increase their population. They will be monitored for several years to measure their growth.
Several landowners allowed me to pollinate, collect and sow capsules of Cyp. pubescens over the past
few years. Last spring, seed from several capsules germinated well, and I have transferred some
seedlings to community pots. Surprisingly, Cyp. acaule also germinated well. Those seedlings are still in the flasks.
For most other genera I have sown, either Knudson's modified "C" medium plus potato extract and
activated charcoal or G & B Mother Flask Medium V work well. But aside from media selection,
a major problem with growing native wild-flowers is breaking seed dormancy. Most species need a cold, damp period of sev
eral weeks to germinate. Many woodland species also need a warm moist period.
If the seed dries out, it may go into a protracted dormancy that is tough to break.
Woodland plants are adapted to a protected environment and their seed dormancy ensures that they germinate only
under favorable conditions. Some ephemerals, such as Claytonia virginica and
Phlox divaricata, germinate at temperatures just above freezing so that they
can take advantage of the early spring moisture and light. Germination rates for Cyp. pubescens decrease
substantially if the seed is allowed to mature. Mature seed may need two winter seasons to germinate.
Liparis seed also will not germinate without two chilling periods. I was ready to throw out the
liparis flasks when I spied several protocorms, which later developed into healthy seedlings.
Seed dormancy may be a major factor limiting germination of G. spectabilis. Few Galearis have
germinated, but those that did grew well on standard media, such as Knudson's modified "C" plus banana.
One seedling produced two new divisions in the flask the first year of growth. If the medium produces
excellent growth, why is the germination rate poor? I am now testing earlier harvest dates to see if that makes a difference.
Spiranthes are the easiest species to grow. Both S. casei and S. cernua germinate without
chilling, although I prefer to chill the flasks so that growth begins in spring for easier production.
Seedlings develop quickly and transfer well from flask to community flat. Plants can bloom as early as
their second summer. All seedlings I have planted out have survived and bloomed. Goodyera also
germinates well, but seedlings require an extra year in the flask before they begin developing green leaves.
Attempts to germinate seed of Platanthera psycodes have been unsuccessful. One reason may be poor seed quality.
Many wildflowers will not produce viable seed if weather conditions are not optimum. The seed I collected last fall,
for instance, looks larger and better developed than seed of previous years, so maybe this year will be successful.
Those flasks are still in cold storage. Germinating Platanthera seed is of special interest to me
because of the decline of our beautiful endangered prairie orchid, Platanthera leucophaea, which
I hope to sow someday if I have luck with P. psycodes.
Never assume that orchids only inhabit wild places far from home. We have many native orchids that go
unnoticed because of their small stature. Old pastures that were never plowed may hold a few surprises,
especially if there are other native species still present. With so many enthusiasts working to unlock the
secrets of germination and growth of our native orchids, perhaps we can increase the availability of seedlings.
We need plants to restore our native-plant communities while we work to protect existing populations.
Scott Weber was born in Evanston, Illinois, but since age five, when he got a toy tractor for Christmas,
he has known that city life was not for him. He was introduced to orchids in grade school through Rex Stout's
Nero Wolfe mysteries, but Scott did not get his first cattleya until 1986. He is a member of the Madison Orchid
Growers Guild and lectures on native orchids and prairie restoration, and he also leads tours for the Nature
Conservancy. • Bluestein Farm, S5920 Lehman Road, Baraboo, Wisconsin 53913.
|
In springtime, Galearis spectabilis is one orchid seen in flower on the author's pasture in Wisconsin.
This clump had only three flowering stalks three years before this picture was taken.
Platanthera psycodes growing in a neighbor's field near the author's fence line.
Several months after a prescribed burn, an oak is once again clothed with foliage. Fire is essential
in maintaining the oak savanna that is home to the terrestrial orchids Spiranthes casei,
Galearis spectabilis, Liparis lififfolia and Liparis loeselii.
Cypripedium parviflorum var. pubescens seedlings after their first growing season in vitro.
The large-flowered yellow lady's-slipper is found widely scattered throughout the Baraboo Hills,
although it has not been found on the author's farm.
Members of the Wisconsin Conservation Corps planting seedlings of Cypripedium reginae.
Sites are marked with steel rebar (to withstand fire) and fenced to keep deer out.
A Cyp. reginae seedling recently planted in a restored habitat.
|
Resources for Native Orchids
ORCHIDS native to North America continue to gain in popularity among both orchid enthusiasts and
those who work to preserve native habitats. Publications of the North American Native Orchid Alliance
and several books offer practical advice for anyone interested in these orchids.
North American
Native Orchid Alliance
The North American Native Orchid Alliance was founded to promote the study and cultivation of native orchids.
The Alliance publishes a periodical about native orchids and holds an annual
meeting, which in 1997 will be August 15 to 17 in Tucson, Arizona.
Information: Nancy A. Webb, 84 Etna Street, Brighton, Massachusetts 02135.
Suggested Reading
General
The Native Orchids of Florida (1972) and The Native Orchids of the United States and Canada (1975),
both by Carlyle A. Luer, MD (New York Botanical Garden, Bronx) and Native Orchids of North America,
by Donovan Correll, PhD (1950. Stanford University Press, Palo Alto), provide an excellent overview
of orchids in this region.
Propagation
North American Terrestrial Orchids: Propagation and Production, edited by Carol Allen (1996.
North American Native Terrestrial Orchid Conference, Germantown).
Identification Guides
Orchids of Indiana, by M. A. Homoya (1993. Indiana Academy of Sciences, Bloomington);
Orchids of Minnesota, by W.R. Smith (1993. University of Minnesota Press, Minneapolis);
The Wild Orchids of California, by R. Coleman (1995. Cornell University Press, Ithaca);
and Wild Orchids of the Northeastern United States, by Paul Martin Brown (1997. Cornell
University Press/Comstock Books, Ithaca).
|
