OrchidSafari ARCHIVES*

TEMPERATE TERRESTRIAL ORCHIDS©

Copyright 1998
Marilyn H.S. Light

The following text will hopefully serve to illustrate the diversity of plant habit and growing conditions possible with the temperate terrestrial orchids. Although I write about North American species, there are many hundreds of other terrestrial orchids such as Diuris and Pterostylis (Australia), Dactylorhiza and Ophrys (Europe), Satyrium (South Africa) and Cypripedium (China) which lend themselves to horticultural use.

INTRODUCTION

There was a time in North America when ice covered much of the land. As the continental ice sheet receded approximately 10,000 years ago, plants resident in the more southern unglaciated regions migrated northward. Pollen records reveal the movement of spruce and fir, then pines, and later hemlock into Southern Ontario. By 2000 B.C. the boreal forest had moved to its present northern limit but remnant pockets of Black Spruce forest and bog remained to the south. Orchids probably grew there then and in other suitable habitats such as rich bottomlands, fens and wet meadows. Lumbering, agriculture, drainage of wetlands and urban sprawl have all taken their toll of that precious legacy. Fortunately there still are some cool woods and other places, many of them in Conservation Areas and Parks, that serve as refugia for native orchids. A concerted effort is required on the part of everyone, residents and visitors alike, to ensure that those orchid communities continue to survive.

A few northern areas escaped glaciation and offer an unique glimpse into the past. The interior of the Yukon Territory and neighboring Alaska is one such place and here we can find the Spotted Lady's Slipper (Cypripedium guttatum). It is also found in neighboring parts of Asia. The North American form of the Spotted Lady's Slipper is heavily blotched magenta pink on pure white. A ventrally spotted dorsal sepal shelters the pouch opening. Large colonies of this orchid can be found growing in acidic moist humus on slopes beneath small trees or in full sun along wet river banks.

Of the 73 orchid species and varieties found in Canada, most may be found growing in the Province of Ontario. Many terrestrial orchids can also be found in suitable habitats in the United States. A few such as the Showy Orchis (Galearis spectabilis) and the Whorled Pogonia (Isotria verticillata) are in the most northern part of their range in Canada: their ranges extend south into the adjacent United States. Others such as the Blunt-leaf Orchid (Platanthera obtusata) and the Bog Adder's Mouth (Malaxis paludosa) are far more common in the north. Much of Canada is quite literally the "land of the silver birch, home of the beaver", endless miles of muskeg, fir and spruce forest that can be home to orchids preferring a cool, moist habitat. Here, if one can stand the hordes of mosquitoes and black flies that make life difficult even for the wildlife, one might find treasures such as the Small Round-leaved Orchis (Amerorchis rotundifolia) and the Sparrow's Egg Lady's Slipper (Cypripedium passerinum). The showy yet diminutive one-leaved plants of Amerorchis carry a raceme of six to eight dainty pale pink to white blooms, the three-lobed lip being attractively spotted reddish-purple. This orchid flowers according to the timing of spring where it grows, from late May through to July. It often self-pollinates. The Sparrow's Egg Lady's Slipper is aptly named: the small egg-shaped pouch is white to pale pink, splashed or dotted with rich purple. This species favors sandy, gravelly shores around rivers flowing into Hudson's and James Bay: it may also be found blooming in June/July in dunes bordering Lake Superior.

Our native orchids are a legacy for future generations. Disturbing, picking, or digging any plant within a National, Provincial, State Parks or in Conservation Areas is prohibited. Disturbance of orchids growing on private land is likewise discouraged. Enthusiasts are instead encouraged to photograph or sketch what they have observed. Orchid lovers should take special care when photographing 'a find' that they do not trample the surround which may support less conspicuous seedlings and other tender plants.

The majority of temperate terrestrial orchids are not in cultivation, indeed many are difficult if not impossible to maintain in cultivation beyond a few seasons especially if the plants have been dug from the wild. If we are ever tempted to raise wild-collected temperate terrestrial orchids we should remember this. When a wild plant blooms after collection it is probably not because of our superb cultural technique but because the bud giving rise to 'our success' had already formed a year prior to acquisition and there were sufficient starch reserves in the root/tuber for the plant to survive. (There is some evidence to suggest that even two seasons growth are prepared for in advance.) It should not surprise us when a collected plant succumbs to cultivation. A close look at the roots will reveal old, inactive mycorrhizae (pelotons) and tissues devoid of starch. The wild plant, separated from a favorable habitat for it and its fungal partner, survives on reserves and when those reserves are depleted, it dies. Pity! It could have continued to flourish in the wild, offering blooms for all to see. Instead it satisfied the urge of an enthusiast who wanted a challenge. If you happen upon some of the orchids described here growing in the wild, please, take only photographs.

ORCHIDS THAT BLOOM IN SPRING (April/May)

Calypso bulbosa - The Fairy Slipper

Some call it the "Fairy Slipper", others the "Hider of the North". Whatever the common name, this exquisite orchid named after Homer's sea nymph in the "Odyssey" is the undisputed treasure of the boreal forest. The plant with its single bloom stands just 6 in (15 cm) tall. One oval leaf emerges in the autumn, overwintering only to wither after spring blooming. The 1 in (2.5 cm) long lip is the dominant floral feature. The foremost part (epichile) is white/pink with a central patch of golden hairs interspersed and surrounded with magenta spots. The pouched, translucent rear of the lip (hypochile) resembles in profile an inverted comma and is vertically striped purple. The petals, sepals and column are bright pink. A photograph taken in profile with back lighting is particularly striking. This orchid can form shallow-rooted mats of corms or occur as one or a few isolated plants perched on a decomposing log. It is vulnerable to trampling feet, forestry practices, and to anything that interferes with seed production such as picking flowers for photographic purposes. When you find this plant, it most probably will be growing in cool, damp humus beneath pure stands of conifer, perhaps in Cypress Hills Provincial Park south east of Calgary, Alberta, or on Vancouver Island, British Columbia, or in Washington State, Oregon, and similar cool locales.

This orchid is in great demand by European hobbyists but alas, dug plants have scant hope of survival. Seed-raised stock might be a candidate for cool greenhouse culture. We look forward to breakthroughs in raising this plant to horticultural status.

Corallorhiza trifida - The Northern Coral-root

I first came across the Northern Coral-root during a spring orienteering meet. Cross-country running can take orchidophiles through interesting terrain including wet seeps, springs and intermittent spring freshets. The bonus is exposure to new 'finds': the detailed 1:15,000 scale orienteering map makes it simple to relocate discoveries once the competition is over. Coral-roots can be inconspicuous but once found, other plants nearby become apparent. So it was while picking my way through soggy humus at the foot of a slope surrounded by sapling Maple and Beech that I discovered my first blooming specimen. The plant stands about 8 in (20 cm), is leafless and carries 10 to 15 white-lipped, yellowish flowers on an upright yellowish green inflorescence. Sometimes the lip is striped or spotted purple. While most Coralroots lack chlorophyll and are considered saprophytes, C. trifida does have some green color: the stem and later the capsules are green. More recently, I have found this orchid in fruit in late July, growing in wet muck surrounding a woodland stream. Luckily, there was not much else growing there so the fruiting plants were quite easily seen: virtually every flower had formed a capsule. Experience has taught me that orchid sites are often orchid-rich sites. I looked around and discovered nearby but in a better drained location, blooming specimens of a superbly colored form of the Spotted Coral-root (Corallorhiza maculata), the Large Round-leaved Orchid (Platanthera orbiculata) and fruiting plants of Hooker's Orchid (Platanthera hookeri).

Coral-roots derive their name from the coralloid underground stem. The plants lack functional roots and are believed to rely on fungal and perhaps even bacterial partners for their nutritional requirements. Although widespread and common, the Northern Coral-root is undoubtedly dependent upon preservation of suitable habitat for its continued existence. Look for it in moist woodland habitats in late May, later further north where it also will be found in drier, more open sites. This orchid is not a candidate for cultivation.

Galearis spectabilis - The Showy Orchis

Begin your search for the Showy Orchis in New Brunswick, in southern Quebec or Ontario, or down through rich hardwood forests of Maine through Georgia. Look for a wooded sun-dappled slope near a brook or spring in early May. The soil will be gravelly, rocky, moist yet well drained. Companion plants are often Beech and Sugar Maple, the Large White Trillium (Trillium grandiflorum), Hepatica americana, and Wild Ginger (Asarum canadense). This long-lived orchid forms discrete mats of flat, glossy, light green leaves. Even if the orchids are not yet in bloom, the plants will be unmistakable. The mauve and white flowers are about (1 in) 2.5 cm long and deserve close inspection to be fully appreciated. You must lie down or suspend a camera upsidedown on a tripod to view the flowers borne on short, five-sided, 15 cm stems. While observing the orchid you may also see the shiny black weevil (Stethobaris) making a meal of the flowers. Later on weevil larvae will devour the seeds in the few capsules that develop or feed within the inflorescence stalk. Mature, entire capsules are seldom seen. This orchid may be long-lived but is never abundant and would probably be vulnerable to any major habitat disruption.

Its long-lived nature makes it a prime candidate for possible horticultural use. I eagerly await the news that it is successfully being raised from seed.

Cypripedium acaule - The Pink or Stemless Lady's Slipper

When queen Bumblebees (Bombus) first emerge from hibernation on warm May mornings, they search for a nectar meal. Some may well visit, and while doing so pollinate, the flowers of the Pink Lady's Slipper. The bumblebees also gather pollen, making a ball of nectar and pollen in which to lay their first egg. I wonder if some larval bumblebees feed on orchid pollen? Pollination success for the Pink Lady's Slipper is largely dependent upon the suitability of spring weather to bumblebee flight, on the number and distribution of resident bees and on the food sources, ie., other flowering plants, that will sustain the bee population long after the orchids have faded. Some years almost every flower in a large colony is pollinated and considerable numbers of capsules are produced but more often, less than 10 percent of the blooms are pollinated. An estimated 15,000 seeds are produced in a capsule. Germinability and the vigor of the resultant seedlings vary according to the seed parent.

Pink Lady's Slippers sometimes carpet the forest floor beneath pines or cedar (Thuja): they grow singly and in discrete clumps. They will also inhabit the shaded margins of sphagnum bogs. Plants in light shade bloom more reliably than those growing in deep shade. The most common lip color is pink but white-pouched blooms can also be found. Some favored locations for the roots of this orchid will be in humus formed beneath a mat of Polypodium fern and Polytrichum moss growing on a granite outcrop, in spruce or pine needle compost over sand, or in coniferous needle humus interspersed with sphagnum moss. Young roots of adult plants and non-emergent seedlings inhabit a very specific layer of partially decomposed plant material between the surface litter and the parent material. Companion plants will include Eastern White Pine (Pinus strobus), Paper Birch (Betula papyifera), Red Oak (Quercus rubra) and Bracken Fern (Pteridium aquilinum) in sandy terrain or the Larch (Larix), Spruce (Picea) and the Pitcher Plant (Sarracenia purpurea) in sphagnum bogs. The orchid may be found in all provinces except British Columbia, ranging from Maine south to Georgia and west into the Minnesota wetlands. Some of the easiest sites to access and view the Pink Lady's Slipper are pine plantations but beware of Poison Ivy (Rhus radicans) which often is found growing nearby!

The Pink Lady's-Slipper is one temperate terrestrial orchid that attracts a lot of horticultural attention. Unfortunately, it can be one of the more challenging orchids to cultivate and so hundreds of thousands of plants have been harvested and sold in garden centers, never to bloom again or even reward the purchaser for the money laid down. Fortunately, great headway has been made towards raising these attractive orchids from seed. Seed-raised stock is now a reality and a commercial option.

Cypripedium arietinum - The Ram's-head Lady's Slipper

The Ram's-head Lady's Slipper is an uncommon diminutive beauty found from Nova Scotia through the Great Lakes region into south central Manitoba. This orchid is so named because of its' resemblance head-on to a charging ram. In profile, the anther could be fancied as a glaring eye. Close examination of the pouch sides reveals the presence of transparent 'windows'. The pollinator enters the lip from above. A dense ruff of soft white hairs surrounding the opening forces the insect to exit elsewhere. Perhaps the 'windows' aid an insect searching for a way out. The flowers are short-lived: those that have been visited exhibit a scar on the anther made by the exiting insect. Furthermore, the upper sepal soon droops to cover the entrance to the lip.

The first time I found the Ram's-head Lady's Slipper blooming was in a sunlit forest glade in eastern Ontario in early June. The soil was shallow: underlying limestone apparent here and there. The surrounding trees included Eastern White Cedar, Spruce and hardwoods: companion plants included the brilliant magenta-flowered Fringed Polygala (Polygala paucifolia). The air in the glade was cool and refreshing although it was a very hot day. Most of the orchids had bloomed previously and had produced seed as was evidenced by remnants of dried stems and capsules. Plants situated in the light gap seem to flower more profusely than those growing in deep shade. If you happen upon this orchid, stay awhile and watch for pollinators which are possibly also visiting the companion flowers.

The Ram's Head Lady's-Slipper is not presently in horticultural demand because it is not particularly showy. I predict that seed-raised stock should be relatively easy to raise.

Cypripedium parviflorum var. pubescens - The Yellow Lady's Slipper

What a tangled taxonomic web the Yellow Lady's Slippers weave. I leave it to the professional taxonomists to specifically name a specimen. All I know is that in one colony of several hundred widely separated clones, we can find tightly twisted and lax-petaled forms, concolor and variably marked staminodes, variously shaped pouches, and petals ranging in color from rich dark brown to pale yellowish green. Whatever their botanical name, the Yellow Lady's Slippers are certainly beauties. The preferred habitat is as variable as the flower. Plants will thrive on a forested southern slope of rich loam overlying marble, in deep deciduous forest humus, in moss and rotting wood by the edge of a fen, or rooted in limestone scree in the foothills of the Rocky Mountains. The greatest threats are loss of habitat and collection pressure. For example, the Yellow Lady's Slipper was once widespread in forests on the Island of Montreal, Quebec, but development has all but eliminated the forests and few plants remain.

The Yellow Lady's Slipper orchids emerge in early May from shoots formed in autumn. Above average rainfall in the year previous often leads to vigorous flower production the following year. Flowers open from mid May through early June depending upon the weather and the locality. If warm sunny weather coincides with peak blooming, the orchids can be marvellously fragrant. Warm weather also hastens the emergence and flight of pollinators such as the solitary bees e.g. Andrena. The bees seem able to learn how to enter and exit a flower efficiently, taking a minute or more with the first flowers visited but less than ten seconds per flower after many blooms have been visited. Most years conditions are not optimal: few capsules are set. Very occasionally when an abundance of pollinators coincides with peak flowering and perfect weather, many flowers will be pollinated. The occasional production of large numbers of capsules does not seem to significantly affect the behavior of the plants the following year, either in terms of shoot or of flower production, provided there is adequate precipitation during the growing season. This long-lived perennial (80 years and counting for one clone) is dependent upon a relatively stable environment to survive. It is quite resilient to short term disruptions such as a six-week drought. If the drought is severe and occurs during the early stages of fruit development as it did in western Quebec in 1991, the capsules are sacrificed for that season. However well adapted this orchid is to natural phenomena, it cannot do battle with the developer or the collector. Fortunately, serious attempts are now being made to raise quantities of this species from seed. This hopefully will relieve collection pressure on wild populations.

ORCHIDS THAT BLOOM IN SUMMER (June/July)

Cypripedium reginae - The Showy Lady's Slipper

The Showy Lady's Slipper is perhaps the most spectacular orchid of eastern and central Canada and the neighboring U.S.. It can form large colonies of plants. One well publicized site, located 75 km (48 miles) west of Ottawa, is the Purdon Conservation Area, Lanark, Ontario. Here a colony of approximately 16,000 Showy Lady's Slippers blooms in mid-June. A boardwalk keeps one dry shod while passing amongst masses of almost meter-tall orchids growing in a fen. Interpretive staff are on hand to answer questions. There are at least three colour forms to be seen and these are easily observed without disturbing the plants. The most common flower has a medium pink pouch. Less frequent are those with carmine red or white lips. The petals and sepals of all forms are uniformly white. When visiting Purdon Fen or other wet conservation areas come prepared with a camera as well as your favorite brand of insect repellent. Fens are favorite breeding grounds for mosquitoes as well as orchids!

The late Joseph Purdon, discovered much about this orchid including the fact that the plants must have adequate sunlight to bloom. He accommodated the orchids by selectively thinning Eastern White Cedar (Thuja) and Larch (Larix) that grow with them. The orchids prefer a moist humus but will cease growing if substantially flooded, especially in spring. Joe Purdon controlled water levels in the fen with a dam. Before he died, he ensured that the plants would be protected by giving his fen to the care of the Mississippi Valley Conservation Authority. There seems little doubt that the Showy Lady's Slipper orchids of Purdon Fen have flourished thanks to the work of this pioneer conservationist.

The Showy Lady's Slipper is now being raised from seed in commercial quantities. There is no excuse to collect plants from the wild.

Malaxis monophylla var. brachypoda - The White Adder's Mouth Orchid

This orchid would not win a beauty contest, indeed few of the genus Malaxis would, but someone must have admired this orchid enough to give it an interesting common name, the White Adder's Mouth Orchid. The tiny 3 mm flowers are pale green to white. As the specific epithet implies, there is generally just one leaf. It is often the leaf and not the blooms that first catch the eye. These are not easy orchids to find although they range from Newfoundland to Manitoba. The favoured habitat is a fen, growing in a mat of Mnium moss in deep shade provided by Eastern White Cedar (Thuja) or in the fen edge amongst sedges. Nearby orchid companions could include Platanthera hyperborea and P. psycodes, Cypripedium reginae and Liparis loeselii. I found my first White Adder's Mouth Orchid when I dropped a lens cap through a tangle of branches and sedges so thick I could barely move. Although the spot was heavily shaded, there were a group of small White Adder's Mouth Orchids, blooming in all their glory. The flowers were white. My second find was in a much more convenient and sunny spot. Convenient, I say because one could examine the flowers without acrobatics! Interestingly, it was the leaf that first caught my eye. It was glossy and strikingly different from nearby and similar-shaped foliage of companion herbs. The flowers on this specimen were green. As tiny and inconspicuous the flowers may be, some are pollinated and develop equally tiny, 5 mm-long capsules. Wetland conservation should ensure the continuity of this species. It is not presently being considered for horticultural use.

Cypripedium montanum - The Mountain Lady's Slipper

When traveling through the foothills of south-western Alberta, through southern British Columbia, or in Montana in June, keep your eye open for this distinctive orchid blooming in roadside ditches and on steep rocky hillsides. The Mountain Lady's Slipper favours well-drained neutral to slightly alkaline soil over limestone. It will frequently be found blooming in full sun but also thrives in light shade amongst trees and shrubs such as Spruce and Alders (Alnus). The white-lipped blooms are unmistakable, even at a distance. The Mountain Lady's Slipper carries two or three sweetly scented flowers on a 20-30 in (50 to 75 cm) stem. The staminode is yellow blotched with mahogany brown, the pouch pure white, and the sepals and slightly twisted petals, a rich purple brown. Other Lady's Slippers such as the yellow-flowered Cypripedium parviflorum may be growing in close proximity. A natural hybrid of C. parviflorum and C. montanum ,(x C. columbianum), has been found in fens and marshes, with alders and horsetails (Equisetum) as companions. The most common form of this natural hybrid has a pale creamy yellow lip and tan sepals and petals although, and as one would expect, the hybrid flower color can be quite variable. Much of the habitat favored by the Mountain Lady's Slipper is subject to natural and human disruption such as landslides, lumbering and grazing yet the orchid has survived. Its greatest vulnerability is to collectors. Progress is now being made concerning seed propagation of this lovely orchid. We look forward to its entry into horticultural trade.

Epipactis gigantea - The Giant Helleborine

The Giant Helleborine is one summer-flowering orchid of the West Coast whose range barely extends into the southern British Columbia interior such as the Kootenay Valley where it blooms in July. This rare orchid can be difficult to find but will be unmistakable when seen. It favors limestone, especially sunny to semi-shaded spots where a hot spring bubbles to the surface. Plants form clumps of stems up to a meter tall, bearing about ten bright rose/orange, 1 in (2.5 cm) wide blooms in loose racemes. Some plants produce greenish flowers. This orchid should not be confused with the Broad-leaved Helleborine (E. helleborine) which has become established in the U.S. and in Canada. This European colonizer has much smaller and less colorful flowers in a more densely packed raceme. The plants are generally solitary or in clumps of 2-4 stems, blooming later, from mid-July into September.

Both species of Helleborine are now raised from seed with blooming plants possible within four to five years. Calopogon tuberosus - The Grass Pink

The Grass Pink (Calopogon tuberosus) and its relative, the Dragon's Mouth Orchid (Arethusa bulbosa), are often found growing and blooming together in sphagnum bogs in Newfoundland, Nova Scotia, southern Quebec and Ontario, and in similar habitat from Maine south to Virginia and west to Minnesota. The Rose Pogonia (Pogonia ophioglossoides) might be found sharing the same bog but will be growing in floating mats of moss rather than in the drier edges. The Grass Pink is a very showy species, having one to six magenta pink, non-resupinate blooms. White and pale pink flowers are occasionally found. The flowers are 3 to 4 cm in diameter and brandish a tuft of bright yellow hairs on a hinged lip. The hairs resemble pollen-bearing anthers even to the point of absorbing long wave ultraviolet light as does real pollen. Pollen-gathering insects such as bees are attracted to the pollen signal of the lip hairs, landon the lip and are immediately thrown onto the column below. If the insect already carries pollen, it is deposited onto the sticky stigma. The sticky material also aids attachment of pollinia to the back of the insect as it escapes. Most flowers are successfully pollinated. The seed germinates readily, some seeds germinating immediately but most requiring a cold period before doing so. Within a year, small hard corms have formed and within three years, the seedlings can bloom. Seed-raised stock is now commercially available.

I have found that the Grass Pink grows in intimate connection with its companion moss. Close inspection of the orchid roots, especially the root hairs, reveals continuity of fungal hyphae (presumably a mycorrhizal partner) from the orchid root via the root hair tip into an adjoining living moss plant. It has been suggested that the orchid is vulnerable to rodents feeding on the corms but loss of unique sphagnum bog habitat is probably a more significant threat. Bogs can be quite dangerous places to visit, especially for the unwary. They are also fragile environments easily damaged by human activity. Some of the most easily accessed bogs are those formed in long, narrow crevices within granite such as exist in coastal regions south of Halifax, Nova Scotia. The granite provides secure footing so one is not tempted to set foot on the bog. The orchids are often so close that they are easily photographed.

Platanthera hyperborea - The Northern Green Orchid

The Northern Green Orchid is one of the most common and widespread orchids found in Canada and in the norther United States. You may find a metre-tall plant growing in the sun-dappled, wet margins of a fen: you can also find much more diminutive plants, no more than 6 to 10 in (15-25 cm) tall, in heavily shaded valleys. Flowering extends over a long period from mid-June to mid-August with plants in warm, wet micro-climates emerging and flowering sooner than those found growing in cooler sites. While the flowers of both forms are indistinguishable, the plants growing in bright, wet locations are generally more robust than those living in the shade. A diminutive albino form has been discovered, absolutely identical to the common green forms. The Northern Green Orchid can be self-pollinating: the pollinia flip down onto the stigma if insects fail in their task. After pollination, the lip curves up over the column, preventing further access to the flower.

I have found this orchid flourishing in a grassed picnic area in Bow Valley Provincial Park, Alberta, blooming in a deeply shaded fen in eastern Ontario, and in an east-facing stream valley in Gatineau Park, Quebec. Extensive habitat destruction could be the only threat to this common orchid. It is not a candidate for propagation at this time.

Platanthera grandiflora and Platanthera psycodes - The Large and Small Purple Fringed-orchids

Tall spires of mauve or purple fringed blooms are the hallmark of these showy eastern North American species. There are three significant features that aid field identification of the Large and Small Purple Fringed-orchids. These are the flowering season, the shape of the nectary opening, and the space between the pollinia. The Large Purple Fringed-orchid, Platanthera grandiflora, has up to 3 cm wide, spurred, mauve purple blooms arranged in a long raceme. The flowers are quite variable in dimensions and in the amount of fringing evident on the lip. Variable also is the color, ranging from rich rosy purple through shades of mauve. The nectary opening is large, round and easily seen. This species is most frequently found growing in the organic silt of marshes or in the rich, slightly acid, sandy loam of wooded stream banks in southwestern Quebec, the Atlantic Provinces and adjacent States. It is endangered in some locales possibly because all suitable habitat has been lost to development. Companion plants include ferns, Red Maple and Birch. In Quebec, flowering occurs during the first week of July, about two weeks before the Small Purple Fringed-orchid begins its blooming season. I have not found the two species growing close together.

The Small Purple Fringed-orchid, Platanthera psycodes, is similar to its larger-flowered relative except for the fact that it generally blooms from mid-July onwards. The flowers are variably colored, from the palest pink, even white, to rosy purple and deep magenta. Robust specimens carry more than 100 flowers on a strong erect raceme. The rectangular-shaped nectary opening is a definitive distinguishing mark. This species can be found growing in damp woods on fen margins, along old beaver dams and silted ponds, or in wet meadows. The soil is generally heavily buffered and neutral. Plants growing in shaded sites are sparsely distributed and not as robust as specimens found in open areas. The foliage of woodland specimens is smooth, glossy dark green and similar to that of P. grandiflora: plants growing in sunny locations have crisp, tough, yellowish green leaves. The Small Purple Fringed-Orchid can have mass flowering of one hundred or more blooming plants per hectare in wet meadows where they grow with sedges, grasses and the fern Onoclea sensibilis. As far as can be determined, the mass flowering is a response to high rainfall one year previous to the event. This precipitation response can extend into two or three more seasons then no blooming plants appear again until above average rainfall triggers another mass flowering. Mass blooming may be important for gene flow in a population: more than 75 percent of the flowers in a mass flowering develop capsules. Using rainfall records as a predictor, we should be able to forecast mass blooming in suitable habitat and develop conservation measures to conserve the seed resource. Simply mowing later in the season after the capsules have dehisced, such as is practiced in Europe with Dactylorhiza, etc. has been suggested as an inexpensive but effective conservation strategy. Although this orchid is widespread and considered common, more study is needed to understand it fully. Both species can be raised from seed and commercial sources may not be far off.

Platanthera orbiculata - The Large Round-leaved Orchid

Two large, round, glossy leaves laying flat on the ground in a cool, damp, boreal forest glade are the hallmark of the elegant yet rarely seen Large Round-leaved Orchid. When not in flower, it might be confused with Hooker's Orchid (P. hookeri) but the leaves of the latter species are half the dimension and gray green rather than bright green. In flower, there is little doubt as to the identity. Hooker's Orchid blooms in early June and has yellow-green flowers. The Large Round-leaved Orchid blooms in July: the long-spurred flowers are whitish-green to white suggesting a long-tongued moth to be the pollinator. This orchid grows in the company of Hemlock (Tsuga), Eastern White Cedar (Thuja), and other orchids such as the Spotted Coralroot (Corallorhiza maculata). I once found a small clump growing beneath a canopy of Balsam Fir (Abies) beside a portage trail in Algonquin Provincial Park. It was a refreshing sight after having carried our canoe and packs up to the height of land between two small lakes. The air here was fresh and cool even though it was a hot, sunny July day.

This orchid is not considered endangered but is not common. Pollination is infrequent and the few specimens I know are self-incompatible.

ORCHIDS THAT BLOOM IN AUTUMN (August/September)

Goodyera pubescens - The Downy Rattlesnake-plantain

The Downy Rattlesnake-plantain may seem an odd common name for such an attractive orchid but the leaves do resemble those of Plantain (Plantago) and snake skin. The leaves are approximately 5 cm long x 2.5 cm wide. The broad midrib is white; the veining a lovely silver tesselation on dark velvet green. This orchid is cherished more for the foliage than for the white flowers which appear in August. It is a long-lived orchid. The foliage is evergreen with large numbers of overlapping rosettes forming gradually over many years. Flowering is sporadic. Some years, many tall stems of inconspicuous, small, white flowers are produced. Other years, few if any colonies flower, even in widely disjunct localities. Climatic conditions seem the only possible explanation for this behavior. The Downy Rattle-snake Plantain is in the northern part of its range in Quebec and Ontario where it most often is found growing in acid humus beneath Hemlock (Tsuga canadensis). Usually, a pond or lake is close by. This uncommon orchid is long-lived but has few defenses against collection pressure which is probably its greatest threat. As far as I know, no seed raised stock is as yet commercially available although such an eventuality is possible.

Spiranthes cernua - The Nodding Ladies'-tresses

My first encounter with this common orchid was not with its flowers but with its roots! We had been planting small trees in a spring reforestation project in southern Quebec. Upon encountering the long, thickened orchid roots, I turned the sod and searched for the inconspicuous rosette. The few, short, grass-like leaves were well disguised. The plant had recently emerged and would not flower before late August or early September. The Nodding Ladies-tresses has the happy although unpredictable capacity to flourish in disturbed habitats such as sand and gravel pits, fields and ditches. It also can be found in moist meadows near the shore of Lake Erie. The soil is almost always sandy and acidic. Companion plants can include Strawberry, Hawkweed (Hieracium), various Asters, and the Fringed Gentian. This is one of the last orchids to bloom. The flowers are sparkling white. An easy way to find this orchid in suitable habitat is to scan the site in the direction of the sun. Any inflorescences will sparkle like jewels in the sunlight. The plants stand about 8 in (20 cm) tall when in bloom.

Spiranthes casei - Case's Ladies'-tresses

Where the Nodding Ladies-tresses have pure white flowers, Case's Ladies-tresses have cream-coloured flowers with yellow towards the base of the lip. These two orchids can be found growing together in close proximity but S. casei will occupy the better drained location. It may also be a little bit taller. The two species flower at slightly different times: Case's Ladies-tresses flowers about two weeks before the Nodding Ladies-tresses, that is, in mid to late August. I have found it growing in a mat of Polytrichum moss, Wild Strawberry and other herbs on exposed sandstone in western Quebec where it is extremely rare. In Ontario, it is restricted to suitable habitat on the massif of very ancient rock known as the Canadian Shield, from the head of Lake Huron into eastern Ontario. All orchids of meadows, ditches and open spaces risk being mowed before they have had an opportunity to reproduce, especially if they bloom late in the season. Conservation measures such as timed mowing permit these orchids to reproduce yet still control coarse herbs and shrubs which might overgrow the dainty plants.

Spiranthes romanzoffiana - The Hooded Ladies'-tresses The Hooded Ladies-tresses is the most widespread of the Canadian Ladies-tresses and one of the earliest to bloom. The flowering season extends from late July through August. This orchid can be found in every Province and Territory of Canada, most frequently growing along rocky and sometimes seasonally flooded shorelines, in seasonally wet pools on exposed granite, in bogs and in marshes. The vanilla-scented flowers are distinctive with the creamy white petals and sepals forming a five-part hood. Where the lip of S. cernua projects out from the petals before bending downwards, the lip of S. romanzoffiana begins to curve downwards within the hood. The plants are small yet robust and up to 40 cm tall when in bloom. As with most species of Spiranthes, the Hooded Ladies-tresses are easiest to locate when in bloom.

CONCLUSION

I remember as a small child, playing amongst Yellow Lady's Slippers blooming beside a woodland stream on the Island of Montreal, Quebec. Before long, the woods had been 'developed', the stream and lady's slippers were no more, and other children now played on that same spot - on streets lined with green lawns. The Lady's Slippers had gone but it was not long before some of the lawns became home to an adept European orchid colonizer, the Broad-leaved Helleborine. First recorded in Canada near Toronto in 1890, the orchid is now found coast to coast in a variety of woodland and urban environments. The orchids, pollinated by wasps, bloom from mid-July to September. Plants are generally 20 in (50 cm) tall including the inflorescence although some specimens stand over a 36 in tall, carrying 10 or more leaves and approximately 80 flowers. These stout plants almost always grow where there is a constant supply of moisture in the soil such as in a ditch or at the foot of a slope near a spring: they are particularly long-lived and emerge every year. Specimens from drier upland sites are much more diminutive, with only three or four leaves and less than a dozen flowers. They are relatively short-lived, some flowering only once before dying. The flower color of the these upland plants is variable, ranging from light and dark pink through yellowish green and cream. The Broad-leaved Helleborine is a colonizer but does not appear to compete with native plants. Indeed it is often the only herb growing on the forest floor beneath the trees. You might also find this European orchid blooming in such unlikely places as a vegetable garden, in lawns, along building foundations and the roadside. It is ironic that this unlikely orchid has become the most likely one to be seen by visitor to Canada.

REFERENCES
Catling, P.M. (1983) Terrestrial Orchids in Canada in North American Terrestrial Orchids, E.H. Plaxton, ed., Michigan Orchid Society, Michigan.

Fisher, R.M. (1980) The Orchids of the Cypress Hills. Published privately, Alberta.

Luer, C.A. (1975) The Native Orchids of the United States and Canada excluding Florida. New York Botanical Garden, New York.

Petrie, W. (1981) Guide to the Orchids of North America. Hancock House Publishers Ltd., North Vancouver.

Sheviak, C.J. (1992) Natural hybridization between Cypripedium montanum and its yellow-lipped relatives. American Orchid Society Bulletin, No. 6, Vol. 61:546-559.

Szczawinski, A.F. (1959) Orchids of British Columbia. British Columbia Provincial Museum Handbook No. 16, British Columbia.

Whiting, R.E. & Catling, P.M. (1986) Orchids of Ontario. The CanaColl Foundation, Ottawa.

Temperate Terrestrial Orchids
by Marilyn Light
WBS, Sat, 11 Feb 98

Present were 18:
James
Steve
Fleur
Marilyn
Uncle Earl
Lois
Harold
John
Sam
Carol
Evlyn
Paula
KB Barrett
foxtail2
Rayma
Butch
Gail
Peterlin

marilyninOttawa
Tonight's topic is a vast one. 'Temperate Terrestrial Orchids'. We can approach the discussion in many ways. I suggest some of the following for starters. We can discuss 1) What kinds of terrestrial orchids there are and how they grow; 2) How to observe these orchids; 3) How to go about growing seed-raised plants in the garden/greenhouse; and 4) Cultural details.

JCY8S
Marilyn - I was very interested in the pre-discussion material, particularly the Epipactis gigantea. I found it in the mountains behind us and brought out one growth many years ago. It grew into a large plant that unfortunately died in all the rain we had two years ago. Marilyn - If the other Epipactis helleborine?) is an import, does it come under the same restrictions as native plants?

marilyninOttawa
Good question, John. It is protected in Europe where it is native. It is protected as are all plants when found growing in parks and conservation areas. Because it belongs to the Orchid Family, it is considered Appendix II under CITES with all the ramifications if one wishes to export it. (I do not believe that is listed for special protection in North America)

Native orchid (Carol in Maryland)
I don't believe there is state protection for Epipactis in my area.

uncleearl (Earl from Vacaville, CA)
Marilyn, as regards 2) 'how to observe.....', how does one go about finding out the locations of native orchids, as well as species and their flowering times?

Native orchid (Carol in Maryland)
Uncleearl, the local chapter of a native plant society will know.

marilyninOttawa
When we start searching for terrestrial orchids, we should first get a good idea of what kinds grow where we intend to search. When I visited New Zealand a few years back, I read all that I could in orchid journals beforehand. I wanted or at least hoped to find examples of Pterostylis and Corybas. I then planned my trip to include natural areas such as parks and similar sites where these orchids were stated to grow. Finding them of course was another challenge. Locals may know where certain plants are located and when they flower but may be reluctant to divulge 'secret' sites. We walked many trails until, when bending down to tie a shoe lace, I spied my first one. A diminutive Pterostylis trulla. Really quite a find being so tiny, and beside it was a Corybas already finished blooming. I observed the site carefully and sure enough, a pattern emerged after several later sightings: these orchids grow just within the edge of an opening (light gap), in Kauri tree leaf litter.

55SS (James in Fresno )
Anyone know anything about Cephalanthera austinae

marilyninOttawa
Cephalanthera or Euburophyton austinae is a West coast species. I have only seen photos as it is quite rare or rarely seen. The common name of C. austinae is the Ghost Orchid.

Fleur (Tasmania)
I have a wonderful little pocket book 'Orchids of Tasmania' it has a colour painting and a location guide for each plant.

marilyninOttawa
Sounds like a delightful pocket guide, Fleur.

[R. Dale Thomas & Charles M. Allen, in cooperation with the Louisiana Department of Wildlife & Fisheries, National Heritage Program, and the Nature Conservancy, Louisiana Field Office put out "Atlas of the Vascular Flora of Louisiana" - Volume 1 is Ferns & Fern Allies, Conifers, & Monocotyledons - monocotyledons of course. Includes geologic, general soils, natural vegetation, and Checklist and Distribution maps! Only $12 including postage in the U.S. This will give an idea of some organizations to check with for something similar for your state...mlg]

Native orchid (Carol in Maryland)
Marilyn, how many different species are recognized in North America?

marilyninOttawa
Carol, I would have to estimate numbers of terrestrial species in all of North America if we include Mexico but I expect that there would of the order of several hundred. If we speak only of the temperate US and Canada, then we a talking of the order of 125. I am not certain of the exact number.

uncleearl (Earl from Vacaville, CA)
Just from intuition, Marilyn, I would guess you to be on the low side!

[There are about 110 species and an additional 40 forms and varieties published giving us of the order of 150 taxa. I am told by Ed Greenwood that we could consider an additional 400 temperate terrestrial species for Mexico. ML.]

marilyninOttawa
In my experience, many terrestrial orchids like edge effect. They grow in a zone between acidic and calcareous soil, or, along the edge of a wetland.

Native orchid (Carol in Maryland)
I found Cyps growing along the road sides in local parks. Maybe that 'edge' effect as far as light goes, too?

marilyninOttawa
Light availability is important for successful flowering of many terrestrial orchids. Many spring-blooming orchids grow quickly before the trees leaf out or the grass grows tall and so take advantage of light when the soil is still cool. Later, the plants are shaded during the heat of summer.

uncleearl (Earl from Vacaville, CA)
From what I've seen in Hawaii, a "lot" of orchids thrive when grown 'on the edge', though some (like vandas) liked to be closer. Orchids can often tolerate higher light levels early and late; just need protection from that hot afternoon stuff.

Native orchid (Carol in Maryland)
I remember reading of some natural hybrids in Cyps. Is it a common occurrence when two species overlap? ...or are bloom times among our native cyps so different?

marilyninOttawa
Certainly bloom times must overlap and the two species must share the same pollinator for cross pollination to happen. Some cyps such as C. parviflorum and C. montanum bloom at the same time and share some of the same pollinators. Several different kinds of bee can visit an orchid and it just takes one cross visit to get hybrid seed. One chance event is enough to start the ball rolling.

[See the delightful article in this quarter's issue of Orchid Digest on the newly discovered Cattleya xmesquitae - natural hybrid of C. nobilior X C. walkeriana var. princeps. both of which bloom in Sep-Oct (late Brazilian winter/early spring)...mlg]

uncleearl (Earl from Vacaville, CA)
Carol - Not only must populations and bloom times overlap: more important is pollinator affinity for both. Then if any of those species (of bees) should also visit a concurrently blooming other orchid species, a hybrid "could" occur.

Native orchid (Carol in Maryland)
I think bumble bees are thought to be the pollinator of Cyp acaule. ...but I don't know any of the other Cyps. Marilyn, do you know?

Fleur (Tasmania)
Is there a connection between temperatures and plant habit? of all our native orchids in Tasmania only one that I know of is not a terrestrial.

(The terrestrial lifestyle takes advantage of the tempered habitat in soil. Great swings of temperature are avoided although it may become quite cold at times. I tend to look at the temperate situation being one not favoring epiphytes rather than favoring terrestrials...ML)

55SS (James in Fresno )
How hard are Cyps to grow in pots?

marilyninOttawa
One of the most important considerations when growing temperate terrestrial orchids in pots is keeping the roots cool. Cyps can be raised in pots. Where we shun overpotting in epiphytic culture, it may be wise to somewhat overpot with terrestrials. Shade the pots and insulate if necessary or sink the pots in beds of gravel or soil. The compost will vary according to the species.

Evlyn
Saw some polystyrene pots one time, like packing material -- thick. Wonder if that would work?

marilyninOttawa
I use polystyrene trays for seedlings. These I sink in the ground. Works well.

Fleur (Tasmania)
We use polystyrene in the base of our pots to help keep things cool.

Native orchid (Carol in Maryland)
Are there many occurrences [of natural hybridization --KB] that are documented? Where I live Cyps are too solitary and few to let the pollinators get around!

marilyninOttawa
Carol. Most orchid populations are discontinuous and quite isolated from each other as far as pollen flow is concerned. We find big differences within and between populations locally. Hand pollination between populations results in almost hybrid vigor yet these populations are ostensibly of the same species. Populations may also intergrade.

(There are known hybrid occurences between Cyp. parviflorum and candidum, between Cyp. parviflorum and montanum. Also there are reported natural hybrids between Platanthera psycodes and P. lacera; and between P. grandiflora and P. lacera. etc...ML)

marilyninOttawa
Cyp. parviflorum has several insect visitors that could be successful pollinators. I have observed three insect pollinator species locally but the most frequent is the bee, Andrena sp. This insect is just the right size to have to squeeze between the anther surface and the pouch edge. This ensures that pollen is picked up as the bee exits the pouch. Too big and the bee must back out. Too small and it never brushes the anther as it exits. I suspect that bumblebees are also occasional pollinators of Cyp. parviflorum var. pubescens. They do visit the flowers, enter the pouch and try to exit out the 'back door' but cannot. They do get some pollen on their head and thorax during the struggle and this is deposited on the front part of the stigma when they enter another flower. If the visitor is the Andrena species, pollen is generally deposited on either of the two back lobes of the stigma.

uncleearl (Earl from Vacaville, CA)
That's another speciation mechanism, Marilyn. Is there any pollen antagonism in Cyps?

marilyninOttawa
Good question, Earl. I investigate pollen germinability in the populations I study. There are big differences between plants as to pollen quality. Stigmas are receptive to pollen (self or out cross) for variable periods of time. Some plants have flowers that are receptive for only a very short time. Other plants are receptive for 8 or more days. We have found the same to be true in three cyp species so far.

uncleearl (Earl from Vacaville, CA)
Makes sense, Marilyn. Probably be true in most populations you study.

Native orchid (Carol in Maryland)
Marilyn, I have a dozen cyps that have wintered in my refrigerator. It is about time they have a spring. What would your suggested method be? Oh, they are 1st year seedlings. If that makes a difference. The older guys are in the cold frame!

marilyninOttawa
I winter cyp seedlings at about 5C or 40F for three months. The length of chilling will probably vary according to the source population. The Showy Ladyslippers require less chilling while the Yellows need a longer period. I try to time things to match our seasons. I keep my seedlings cold until about now (mid-February). Those in flasks already chilled since November will now be planted into soil and kept cold until March/April or whenever spring comes then put outdoors. These orchids grow their roots when the soil is cool, in fall and in spring.

Native orchid (Carol in Maryland)
Do you just take them abruptly from cold storage? ...or do you have a gradual change that you put them through?

marilyninOttawa
Carol, The seedlings are taken from the cold to a cool location. Say from 40F to 50F. I usually top dress the tray/pot with crushed deciduous leaves such as maple leaves. This keeps the shoot buds shaded and maintains a more uniform soil temperature. The warm up past that is gradual. Buds will break dormancy when the soil temperature rises above 55F.

marilyninOttawa
The Platantheras are the next group of orchids that I see making their way into the horticultural market. Several are now being raised from seed much as are the European Dactylorhizas.

(I highly recommend "North American Native Terrestrial Orchids: Propagation and Production," 1996, edited by Carol Allen, as a reference to propagation work involving terrestrial orchids...ML)