Monarchs Arrive in Europe!

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Monarch butterflies, once strictly limited to the New World, are now found in Europe too. Source: Kenneth Dwain Harrelson, Wikimedia Commons

The famous migratory butterfly, the monarch (Danaus plexippus), is native to North and Central America and northern South America. (Elsewhere in South America, it is replaced by the southern monarch [Danaus erippus], a similar but essentially non-migratory species.) But, while the adult butterfly can feed on the nectar of a wide range of flowers, the larva of this species is extremely limited in its food sources. It can consume only milkweed leaves (Asclepias spp.), a genus originally limited to the New World, as well as those of its next-of-kin, the false cotton bush (Gomphocarpus spp.), originally from South Africa. However, the monarch never managed to find the way to South Africa. So, for tens of thousands of years, the monarch was strictly limited to the New World where milkweeds abound.

Expansionist Ideas

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The narrow leaf false cotton bush (Gomphocarpus fruticosus) is one of the food plants that have allowed the monarch to settle in new territories. Source: Xemenendura, Wikimedia Commons

That’s no longer the case! Humans have planted various species of false cotton bush and milkweed as ornamental plants, and a few have become naturalized well outside of their natural range. Tropical milkweed (Asclepias curassavica) and narrow leaf false cotton bush (Gomphocarpus fruticosus), for example, are well established in most subtropical regions around the world and that’s been the case since at least the beginning of the 19th century.

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Monarch butterfly distribution today  . Source: monarchlab.org

The northern monarch (D. plexippus) has taken advantage of the widened distribution of its host plants to expand its range. It first established a foothold in the Hawaiian Islands in the 1840s and from there spread throughout the islands of the South Pacific in the 1850s and 1860s. It first appeared in Australia and New Zealand in the 1870s and is now firmly entrenched in both countries, even fairly common in some areas.

So much for the Pacific. It somehow crossed the Atlantic as well, first showing up in the Canary Islands, off the coast of Africa, in the 1880s, then spreading to other islands in Macaronesia (Madeira, the Azores, etc.).

By Wind, Wing or Sail?

No one knows for certain how this dispersion took place. Did the butterfly travel as a stowaway on boats from one continent to another? Did it fly on its own? (Since adults can travel 1,400 miles [2,200 km] in the wild, that’s far from impossible). Or were they carried across oceans by the wind? We may never know.

Now Continental Europe

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Monarch butterfly and caterpillar on tropical milkweed (Asclepias curassavica). Source: www.jungledragon.com

Monarch butterflies have been showing up sporadically in Europe for hundreds of years, but at first, showed no inclination of trying to settle down permanently. Then in 1980, a population of monarchs was found naturalized in southern Spain (Malaga) and it has since spread along the west coast of Portugal and the southern coast of Spain, two regions where tropical milkweed (Asclepias curassavica) and narrow-leaf false cotton bush (Gomphocarpus fruticosus) are well established. It is also seen in summer and early fall in France and the British Isles. In fact, one female laid eggs on a milkweed in Kew Gardens in London, but the gardeners there brought them indoors to hatch, so the next generation never had a chance to start a local generation.

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Butterfly weed (A. tuberosa) is a hardy species that is grown as an ornamental in Europe, but probably not extensively enough to support a local population of monarch butterflies. Source: Aaron Carlson, Wikimedia Commons

Indeed, the monarch butterfly may never be able to fully settle in temperate Europe due to the lack of cold hardy milkweeds there. Some hardy species are now being grown as perennials, but only in gardens. Butterfly weed (A. tuberosa) and swamp milkweed (A. incarnata), for example, are known to European gardeners, but have not naturalized, which limits the possibilities for breeding monarch to settle there permanently.

Still, the many European readers of this blog can monitor the presence of this insect in their gardens in summer and early fall. The monarch is easy to recognize not only because of its flamboyant orange color with black veins, but also because it is the largest butterfly in Europe.


Whether the monarch only maintains a tenuous foothold in Europe or fully establishes itself remains to be seen. And whether its presence on European soil is a good thing or not is also questionable. Only time will tell!

Plant More Than Milkweeds to Save Monarchs

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The enigmatic monarch butterfly is having a hard time surviving. Source: LyWashu, Wikimedia Commons

In North America, the serious decline of the monarch butterfly (Danaus plexippus), the black-veined orange migratory butterfly that winters in Mexico and California and travels all the way to Canada in the summer, has been highly publicized. It’s hard to imagine of anyone who hasn’t heard about it. Its population has been declining for at least 50 years, and since 2008, the population has dropped dramatically, from 1 billion to 93 million butterflies. That still sounds like a lot of butterflies, but if the population keeps dropping at this rate, within a generation this emblematic butterfly will no longer grace our fields and gardens.

Several authorities attribute the decline to modern agricultural practices, especially the widespread use of herbicides (deadly to milkweeds, the unique food of monarch caterpillars), as they create vast surfaces where nothing but the crop in question (maize, soybeans, etc.) grows. Monocultures stretching as far as the eye see offer neither food nor shelter to migrating monarchs.

In addition, several years of climate disruption in Texas, a state through which almost all the monarchs in eastern America have to pass, including severe droughts and unseasonable frosts, have aggravated the situation. As have the illegal cutting of forests in Mexico where the butterflies spend several months in winter dormancy and the indiscriminate use of insecticides everywhere along their route.

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There are programs all over North America teaching people what they can so to help protect monarch butterflies. Source: planobluestem.blogspot.ca

In recent years, associations have appeared throughout North America that seek to protect monarch butterflies. Most have developed some sort of program that asks home gardeners to “do their share” and offer an oasis for monarchs on their lot: a garden often called a monarch way station, somewhere monarch butterflies will not only be tolerated, but actually encouraged.

The principle is certainly simple enough: monarch butterflies need flowers in order to survive, so if enough people create flower beds all along the route that butterflies follow from Mexico to southern Canada, that should help the monarch population to recover!

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A monarch caterpillar munching on the leaf of a butterfly weed (A. tuberosa). Source: Marshal Hedin, Wikimedia Commons

Especially put forward is the idea of planting milkweeds (Asclepias spp.). Indeed, monarch larvae (caterpillars) can only feed on milkweeds (and plants of the related African genus Gomphocarpus): they have no other source of food. They’ll die if offered anything else. Plant a milkweed, save a butterfly: it certainly sounds simple enough.

No Sooner Said Than Done!

Gardeners definitely understood the last point. They are planting more milkweeds. The sale of milkweeds, once rather obscure plants, is booming in Canada and the United States: everybody seems to be planting them, notably with school teachers pushing the idea in the classroom and kids asking their parents to plant them … and that’s great. Every little effort helps. But planting milkweeds is not going to entirely solve the problem: it’s a bit more complicated than that.

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Monarch butterflies feed on the nectar of a wide range of flowers, not just milkweeds. Here they’re feeding on wild ageratum (Conoclinium coelestinum). Source: pxhere.com.

Just as important as planting milkweeds to feed larvae is planting and maintaining nectar plants for adult butterflies. Adult monarchs, in fact, are not in any way limited to milkweed flowers, but instead feed on a wide range of nectar-rich blooms. They need plants in bloom as a food source whenever they’re in a given region. That is, from spring through late fall in the south and in the summer and very early fall in the northern part of their range.

Storing Up for the Return Trip

It is especially important to offer an abundance of nectar-rich flowers in late summer and in fall. Here’s why:

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The monarch’s migration: step by step. Source: askabiologist.asu.edu

Contrary to their spring migration, which is multi-generational (monarchs migrate in stages, stopping on their way north to lay eggs at different points and produce new butterflies that will complete the route to the North, and therefore milkweeds are essential for feeding the caterpillars of the up-and-coming generation), the return from the North to the South is done in a single generation. The same butterfly born in the summer on a milkweed in, say, Northern Ontario, at the extreme northern edge of the monarch’s range, has to fly all the way to the heart of Mexico, a distance of about 3,000 miles (4,800 kilometers). Before it leaves, at summer’s end, it needs to stock up on lipids (fats) that will help carry it down to Mexico. Then all along its route south, it needs to stop regularly to feed on flowers rich in nectar.

Note that milkweeds (Asclepias) are not at all necessary on the return trip and at any rate, most will have finished blooming by then. Monarchs don’t need milkweeds in the fall, because the females will not be laying eggs on their way south, nor will there be any caterpillars that need to feed on milkweed leaves. Actually, it won’t be until March or April of the following year, when monarch butterflies wake up after their winter dormancy and start to fly north, that they need to find milkweeds on which to lay their eggs. Instead, southward migrating monarchs need other nectar-rich flowers: late-blooming ones.

This is such an important factor that some scientists believe that to try to boost the monarch population, planting milkweeds is considerably less important than preserving and planting late-blooming flowering plants! (See the study done by Cornell University: Linking the continental migratory cycle of the monarch butterfly to understand its population decline.)

Create Your Own Monarch Oasis

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A garden designed as a monarch oasis. Source: esusbranch.wordpress.com

If you want to create a monarch garden on your lot or organize one at your school or in a local park, here are some considerations:

  1. Ideally, it should be in full sun in a spot protected from the wind.
  2. It should contain milkweeds (Asclepias spp.) to feed the caterpillars in the spring (southern locations) and in early to mid-summer (elsewhere), as well as a good variety of nectar-bearing flowers to feed the adult butterflies throughout the summer and into fall.
  3. The larger the flower bed, the more it will be used. (Do you really need the vast sea of green lawn that surrounds most houses and that is the equivalent of a monarch butterfly desert?)
  4. You have to learn to accept a bit of imperfection in a butterfly garden. Yes, some leaves will be munched on: the caterpillars need to eat something! And there will probably be less attractive insects on your milkweeds (they do have their share of insect pests) you’d do best to learn to ignore.
  5. Avoid treating your butterfly garden with products toxic to butterflies, such as insecticides. If you feel you have to treat plants in the garden, prefer gentle treatments like a sharp spray of water or hand picking. Even organic insecticides, likes insecticidal soap and neem, can harm caterpillars and butterflies.

Plants That Feed Monarchs

To feed monarch caterpillars, it’s essential to include milkweeds in your monarch oasis.

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The two most common perennial milkweeds in garden centers: butterfly weed (Asclepias tuberosa), left, and swamp milkweed (Asclepias incarnata), right. Source: Derek Ramsey, WC & http://www.robsplants.com

Butterfly weed (A. tuberosa), zone 4, with orange or yellow flowers, and swamp milkweed (A. incarnata), zone 3, with pink or white flowers, are the easiest to find in plant nurseries. The first prefers very well-drained to dry soils, while the second is better adapted to average garden soils, which are richer and more humid.

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Common milkweed (Asclepias syriaca) is a weedier species you may not need to grow if it is common in your area. Source: Stefan.lefnaer, Wikimedia Commons

In eastern North America, common milkweed (A. syriaca) is already widespread in the wild, as is its western equivalent, showy milkweed (A. speciosa), in its territory. Neither are widely available commercially and can be a bit invasive in a flower bed.

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Tropical milkweed (Asclepias curassavica) is a good container plant. Source:  Jeevan Jose, Wikimedia Commons

Gardeners in mild climates and those limited to balcony and patio gardening could try tropical milkweed (A. curassavica). It will grow as a perennial in zones 9 to 11 and in pots as an annual in colder climates.

There are some 140 other milkweed species, but the commercial distribution of most is very limited.

Nectar Plants

So, you’ve planted milkweeds to feed monarch caterpillars. Now you have to nourish the adult butterflies. For that, you need a good variety of plants that produce abundant nectar. Milkweeds do work, but likely won’t be enough. You need plenty of flowers of all kinds.

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Monarchs prefer clustered flowers, like those of ‘Herbstfreude’ sedum (Hylotelephium ‘Herbstfreude’, syn. Sedum ‘Herbstfreude’). Source: Darkone, Wikimedia Commons

Butterfly plants usually produce inflorescences with clustered flowers, such as are found in the Asteraceae, Apiaceae and Verbenaceae families. Either loose clusters, like lantanas or verbenas, or dense flower heads, like rudbeckias and echinaceas, will do. The latter even come with a butterfly landing platform, the ray flowers (their so-called petals) that surround the flower head. Butterflies generally find individual flowers less attractive.

Brightly colored flowers attract monarchs, but they are relatively indifferent to perfumes (except for the fragrance of milkweeds, which they can detect from a great distance). Beware of double flowers: sometimes, but not always, the extra petioles render the nectar inaccessible to monarchs.

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Don’t be afraid to mix imported flowers with native ones: studies show this attracts more butterflies. Source: charismaticplanet.com

The traditional belief that you should choose strictly native flowers for your monarch oasis is now considered erroneous: recent studies show that a mixture of native and imported flowers attracts and feeds the most butterflies.

Later Bloomers

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Late-blooming nectar plants, like this Canada goldenrod (Solidago canadensis), are the most important suppliers of pollen for the monarchs’ trip back to Mexico. Source: Harry Rose, Wikimedia Commons

At the end of the summer, things start to get serious. Monarchs will need to drink a lot of nectar to accumulate good reserves, essential for their flight south. Thus, the utility of nectar-rich flowers increases as summer winds down. The list below concentrates on plants that will be in bloom from mid-August on, the time of year when monarchs need nectar the most:

  1. Ageratum (Ageratum spp.) — annual
  2. Ageratum, Hardy (Conoclinium spp.) — zones 5–10
  3. Alyssum (Lobularia × hybridum) — annual or zones 9–11
  4. Aster (Aster spp., Symphyotrichum spp. and several other genera) — zones 2–9
  5. Balloon Plant (Gomphocarpus spp.) — annual or zones 10–11
  6. Bergamot, Wild (Monarda fistulosa) — zones 3–9
  7. Black-eyed Susan (Rudbeckia spp.) — zones 3–9
  8. Blanket Flower (Gaillardia spp.) — annual or zones 3–10
  9. Blazing Star (Liatris spp.) — zones 3–8
  10. Bluebeard (Caryopteris spp.) — zones 5–9
  11. Boltonia (Boltonia spp.) zones 3–8
  12. Boneset (Eupatorium spp.) — zones 3–9
  13. Bottlebrush (Callistemon spp.) — zones 9–11
  14. Butterfly Bush (Buddleia spp.) — zones 6–9
  15. Buttonbush (Cephalanthus occidentalis) — zones 4–10
  16. Catmint (Nepeta spp.) — zones 3–9
  17. Celosia (Celosia spp.)  – annual or zones 10–11
  18. Chives, Garlic (Allium tuberosum) — zones 3–8
  19. Cockscomb (Celosia argentea cristata) — annual or zones 10–11
  20. Coneflower (Echinacea spp.) — zones 3–9
  21. Coreopsis (Coreopsis spp.) — zones 3–9
  22. Cosmos (Cosmos spp,) — annual
  23. Crownbeard (Verbesina spp.)  – zones 4–8
  24. Culver’s Root (Veronicastrum spp.) — zones 3–9
  25. Dahlia (Dahlia × hortensis) — annual  
  26. Dewdrops, Golden (Duranta spp.) — zones 9–11
  27. Echinacea (Echinacea spp.) — zones 3–9
  28. Flame Vine (Pseudogynoxys chenopodioides, syn. Senecio confusus) — annual or zones 10–11
  29. Gaillardia (Gaillardia spp.) — annual or zones 3–10
  30. Giant hyssop (Agastache spp.) — zones 2–10, according to species
  31. Globeflower (Gomphrena spp.) —annual
  32. Goldenrod (Solidago spp.) — zones 3–9
  33. Heliotrope (Heliotropium arborescens) – annual or zones 9-11
  34. Hempvine, Climbing (Mikania scandens) — zones 6–9
  35. Ironweed (Vernonia spp.)  – zones 4–9
  36. Joe-Pye Weed (Eutrochium, formerly Eupatorium spp.) — zones 3–9
  37. Lantana (Lantana spp.) — annual or zones 9–11
  38. Marigold (Tagetes spp.) — annual
  39. Milkweed (Asclepias spp.) — zones 3–10
  40. Mint, Moutain (Pycnanthemum spp.) — zones 4–8
  41. Mistflower (Conoclinium spp.) — zones 5–10
  42. Phlox, Garden (Phlox paniculata) — zones 3–8
  43. Porterweed (Stachytarpheta spp.) — annual or zones 9–11
  44. Rose (Rosa spp., varieties with single flowers) — zones 3–10
  45. Rosinweed (Silphium spp.) — zones 4–8
  46. Rudbeckia (Rudbeckia spp.)  — zones 3–9
  47. Sage (Salvia spp.) — annual or zones 5–11
  48. Sage, Russian (Perovskia spp.) — zones 4b-9
  49. Sedum (Sedum spp. et Hylotelephium spp.) — zones 3–9
  50. Spirea, Blue (Caryopteris spp.) — zones 5–9
  51. Spirea (Spiraea spp.) — zones 3–8
  52. Star Flower, Egyptian (Pentas lanceolata) — annual or zones 9–11
  53. Sunflower (Helianthus annua) — annual
  54. Sunflower, Mexican (Tithonia rotundifolia) — annual
  55. Thoroughwort (Eupatorium spp.) — zones 3–9
  56. Tickseed (Coreopsis spp.) — zones 3–9
  57. Verbena, Garden (Verbena x hybrida) — annual or zones 9–10
  58. Verbena, Rose (Glandularia canadensis) — annual or zones 6–9
  59. Verbena, Tall (Verbena bonariensis) — annual or zones 7–9
  60. Yarrow (Achillea spp.) – zones 3-9, according to species
  61. Zinnia (Zinnia spp.) — annual

Do your bit to save monarch butterflies: plant a flower garden!20180328A LyWashu, WC

The Titillating Sex Life of Orchids

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Orchid flowers make themselves as seductive as possible! Source: thecliparts.com, Clipart Library & pngimg.com

Flowers are all about sex. If they look good and smell good, it’s not to please us humans, but to better seduce their pollinators, because most need cross pollination (transfer of pollen from the flower of one plant to the flower of another of the same species) in order to reproduce. And orchids are the masters of sex when it comes to the world of plants.

How Plants “Do It”

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Wind-borne pollen (here from pine trees) can be so copious it coats everything. Source: www.asthmacenter.com

Many plants (conifers, oaks, grasses, etc.) produce extra-light pollen in copious quantities then liberate it massively into the air so it will be carried away by the wind. They do so in the hopes (yes, I’m going to go a bit anthropomorphic in this blog; it just makes the explanations so much simpler!) that a single pollen grain will accidentally land on a receptive flower of the right species. Wind pollination does work (otherwise, the species that do it would have gone extinct), but what a waste of resources! Sometimes the entire landscape is covered with a thin layer of pollen that will never serve the plant in any way.

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Most insect-pollinated flowers offer an abundant source of nectar to encourage repeat visits. Source: http://www.sarahplusbees.com

Other plants use a more reliable pollinator than the wind—usually an insect, although occasionally a bird (a hummingbird, for example) or a mammal—to carry their pollen from one flower to another. Many essentially offer an open bar: they give as a reward a generous amount of nectar and pollen and are none too picky when it comes to their suitors. Think of the common oxeye daisy, Leucanthemum vulgare, found in fields everywhere. It gives off a subtle, sugary, generic odor that attracts a wide range of insects and its florets just drip with nectar. It likewise produces more pollen that it needs so pollen-eating insects can have their share. The daisy can be pollinated by bees, flies, butterflies, beetles or wasps of many different species.

Scientists have a way of spelling things out quite bluntly and call such blooms promiscuous flowers. (If they hadn’t said it, I would have!) Such plants are counting on the likelihood that one of their many pollen-laden visitors will eventually land on a plant of the same species and that some of the pollen that stuck to its body as it fed will come free and ensure fertilization. That’s still a lot of nibbles and booze (oops, I mean pollen and nectar) to give away, but at least the investment is worthwhile if they achieve pollination.

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The yucca moth absolutely depends on the yucca for its survival (Yucca spp.) and the yucca can only be pollinated by the yucca moth. Source: Google Images

Other flowers are very specific … and orchids are often in this group. Pollinator-specific flowers come in a distinct color or form, have barriers to keep unwanted pollinators out or a scent that is only appreciated by one specific pollinator or at least a limited number of pollinators, thus forming a specific plant-pollinator interaction. A good example among non-orchids is the yucca moth (Tegeticula sp.), which pollinates only yuccas (Yucca sp.). The plant absolutely needs the pollinator and the pollinator can’t get along without the plant. Such plants don’t need to produce as much pollen and certainly not as much nectar as promiscuous flowers … but they usually do have to curry the favor of their pollinators by rewarding them in some way: pollen, nectar, oils, housing, etc.

Orchids, though, are not as charitable as most plants. Although their heavy pollen can’t be carried by the wind and they are almost always pollinated by insects (more rarely by mammals or birds), they are very stingy with their pollen. They don’t produce “quantities” of pollen, only two pollinia or pollen masses (singular: pollinium) per flower. And most are not particularly generous with their nectar either. Indeed, many produce no nectar at all.

Obviously, it’s vital for a flower with only two pollinia that the insect that picks up its ever-so-rare pollen deposits them on another orchid of the just right species. Thus, orchids will go to almost any length to please their specific pollinator, using clever combinations of colors, scents, shapes and textures to better seduce it … but many still don’t feed it!

Deceptive Flowers

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Deceptive orchids trick insects into pollinating them, but offer nothing in return. Source: scarletblack.ca & moziru.com

The way orchids get away with “offeriing the product, but not delivering the goods” is by mimicry. They try to replicate things their pollinator will find attractive: flowers, fellow insects … even rotting meat! They can do this by smell, taste, appearance, texture, etc. Their pollinator visits them expecting one thing, but gets … nothing in return. But it leaves with orchid pollinia glued to its body.

One estimate suggests that of the 20,000 species of orchids, about 8,000 are so-called “deceptive flowers”: they claim to offer something interesting to a pollinator, but don’t deliver. Orchids are not the only deceptive flowers, but they are by far the best at floral trickery.

Let’s look at a few examples:

Seducing the Orchid Bee

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The lip of the bee orchid looks like a female bee, complete with wings, the better to seduce the orchid bee into pollinating it. Source: Ophrys apifera, BerndH, Wikimedia Commons

The bee orchid (Ophrys apifera) is a terrestrial European orchid, also called (I didn’t invent this!) the prostitute orchid. It sets out to seduce a male bee of an appropriate species (different solitary bees in the genera Tetralonia and Eucera). To do so, the bee orchid starts by producing a flower that is physically quite similar to the female of the solitary bee. It has the same color (from a bee’s point of view; we don’t see colors the way they do), is the same size and even offers a similar shaggy texture.

But the coup de grâce is the perfume: the flower releases a pheromone (sex hormone) very similar to that of the female bee, but not quite the same. Tantalizingly different, you might say. Enough so that, if the male bee has to choose between the orchid and a female of his species, he often chooses the orchid!

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Male bee orchid with pollinia stuck to his head. Source: pinterest

When he lands and tries to copulate with the flower, his movements release the flower’s pollinia that end up literally glued to his head. Frustrated by the flower’s lackluster response, though, he leaves.

Bees may not be very intelligent, but they do learn. As a result, he’ll avoid the next few bee orchid flowers he encounters, remembering the disastrous results of his initial flirtation. But the further away he gets from the original flower, the more his memory fades and soon enough, he’s ready to try again. By now, though, he’s at a considerable distance from the original plant and this ensures that the cross-pollination that occurs will be between plants that are genetically distinct, thus avoiding any consanguinity. Just what the orchid wants!

When he lands on the new flower, the pollinia, if he’s wearing any, get caught in structures in the flower and are literally ripped from his head, then replaced by new ones.

Let’s hope he eventually finds a sweetheart of his own species before he dies of exhaustion!

The bee orchid is hardly an exception. Many orchids mimic the scent of female insects and induce the pseudo-copulation of males for their own reproductive purposes, but few mimic the appearance of the female quite as well as the bee orchid.

A Swarm of Pseudo-Bees

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The pretty flowers of many Oncidium orchids are designed to look like a swarm of bees. Source: sitecgdw.com

Some species of Oncidium in South and Central America have flowers that subtly mimic the appearance of local bees (genus Centris), but it’s not for the purpose of sexually attracting them. The small flowers are grouped in large numbers on arching stems that move in the slightest breeze, even to the point of seeming to shake.

Male Centris bees are very territorial by nature, and when they see what seems to be a swarm of dancing bees invading their space, they go on the attack, repeatedly dive-bombing the flowers … and when they do, they pick up pollinia by accident. After the exhausting but fruitless attack, they pull back, then discover another “flowery swarm” elsewhere, and attack that too, dropping off pollinia from the first orchid, thus ensuring fertilization, and picking up fresh pollinia. And before they learn better (and they will), this can happen four or five times, leaving the orchids pregnant and happy and the bees confused and frustrated.

Lady’s Slippers

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The swollen pouch of a lady’s slipper orchid (here, Cypripedium pubescens) is actually an insect trap … and part of an elaborate pollination scheme! Source: D. Gordon E. Robertson, Wikimedia Commons

Deceptive orchids aren’t limited strictly to the tropics. The beautiful lady’s slipper (Cypripedium spp.), found, in one form or another, throughout much of the Northern Hemisphere, even in the boreal forest … is definitely on the list of deceptive flowers. In other words, she really isn’t much of a lady!

Its lip, a mutated petal in the shape of a pouch, gives off a honeyed smell that implies an abundant supply of nectar. The insect (a fly, bumblebee or solitary bee, depending on the species of lady slipper: each has its own favorite) lands on the lip looking for the promised nectar. It wanders towards the greatest intensity of scent … to discover itself on the smooth inner surface of the lip. Thus, it slips to the bottom of the pouch where the sweet scent is strongest, figuring it has hit the jackpot, but no, there is no nectar at all. Worse, when it tries to leave, there are downward inclined hairs that prevent it from going back the way it came. The insect is now a prisoner.

Eventually, it discovers an opening at the bottom of the flower and tries to wriggle its way out. In doing so, it drops off any pollinia it was carrying from a previous lady slipper encounter, thus ensuring pollination, but the exit hole is so arranged that, when it does it free, new pollinia are automatically glued to it.

The lady’s slipper orchid is far from the only orchid to use this technique. It’s a fairly common ploy among deceptive orchids.

Stinky Blooms

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The disgustingly scented flowers of Bulbophyllum phalaenopsis look and smell like rotting meat so as to better seduce their carrion fly pollinator. Source: C T Johansson, Wikimedia Commons

The gigantic orchid Bulbophyllum phalaenopsis will surely never win any beauty contest. It has to have just about the ugliest flower of any orchid.

Its 15 to 20 reddish-purple flowers look like rotten meat and swarm with fleshy projections said to look like wriggly maggots. In addition, it emits a truly nauseating odor, one said to replicate the stench of a thousand dead elephants rotting in the sun. It does so to attract a female carrion fly looking for a place to lay her eggs. (This is called “brood site deception.”) As she does so, she inadvertently picks up the flower’s pollinia, then carries them off to another flower. When the fly’s eggs hatch, they simply die: there’s nothing there they can actually feed on.

Again, Bulbophyllum phalaenopsis is not alone. Many orchids, including the those in the foreboding-sounding Dracula genus, likewise attract carrions flies with an odor that seems unbearable to our nostrils, yet so enticing to flies!

Flower Mimics

Not all orchid flowers mimic female insects, marauding bees or dead elephants. Many disguise themselves as other flowers.

When an abundant plant has found the key to success with pollinators, it’s far from uncommon for a local orchid to learn to imitate it to take advantage of its pollinators.

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One of these three flowers is deceptive: it has nothing to offer its insect pollinators. Source: Guérin Nicolas, Mercewiki et Dick Culbert, Wikimedia Commons

In South and Central America, for example, there is a milkweed (Asclepias curassavica) and a lantana (Lantana camara) both of whose flowers share the same color combination (orange with a yellow center) and also the same pollinators—notably specific species of wasps and butterflies—and the two produce abundant nectar to ensure their favorite pollen carriers visit faithfully and thus transfer their pollen. However, a few species of Epidendrum—including E. radicans—have learned to mimic them by producing flowers of exactly the same colors … but with the difference that these orchids offer no reward whatsoever. The insects visit, pick up their orchid’s pollinia, and leave hungry and confused, the promised nectar simply being absent.

Again, there are hundreds of other orchids that mimic other flowers so they can “steal” their pollinators. It’s just something orchids do!

50 Shades of Orchid Sex

Obviously, there are many other deviations in the twisted sex life of orchids that I could have told you about:

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A trigger mechanism in the flower of a Catasetum shoots pollen with such force it can stun the pollinating bee. Source: catasetum-ian.blogspot.ca

  • A Catasetum that shoots its pollinia onto the head of its pollinator with such force that it is sometimes knocked unconscious or even killed by the experience;
  • Darwin’s orchid (Angraecum sesquipedale) so badly wants to preserve its precious nectar from nectar thieves that it stores it at the bottom of a one foot (30 cm) spur so that only its exclusive pollinator, a moth called Xanthopan morgani praedicta, whose probiscus is just long enough, can reach it;
  • Holcoglossum amesianum which, if its preferred pollinator doesn’t show up, self-pollinates in such a very physical way that I wouldn’t dare to describe it in a blog that could be easily read by children;
  • And many more!

Decidedly, orchids are the vixens of the plant world … and they seduce humans too! After all, what do we do when so they shamelessly offer themselves to all and sundry with their sultry flowers, but take them from the wild and grow them in our homes and gardens!

Sex sells: it always has!20180115A thecliparts.com, Clipart Library & pngimg.com