Friday, May 31, 2013

Pollination of the Showy Orchis

  Rube Goldberg could have used the Showy Orchis pollination system as an inspiration for one of his elaborate contraptions.  The Showy Orchis uses a complex combination of some commonplace components to effect cross-pollination.  One of the system's components is an intentionally sticky situation - on the part of the orchid.  As a result of this orchid's pollination process, its bumblebee visitors temporarily gain an extra pair of antennae.  It follows that a naturalist thinks about this remarkable pollination method every time he sees a Showy Orchis.
Showy Orchis - Galearis spectabilis
  When a bumblebee visits a Showy Orchis for some nectar, it gets more than it bargained for... it leaves with an extra pair of antennae glued to its head.  Here is a photo of the orchid's pollinia stuck to a twig - which I used in place of a bee for demonstrative purposes.
Showy Orchis pollinia glued to a "fake" bee
 How does a bumblebee get tricked into getting these pollinia glued to its head?

   Well, let's take a close look at this orchid's pollination mechanism.  Of course, the whole flower has a part to play in this masterfully designed system - one designed to help ensure cross-pollination.
  • The large white lip serves as a landing pad for the bees.  
  • The long white spur is where the nectar collects to attract the long-tongued bees that visit the orchid.  
  • The little orchid's lavender hood protects the pollination mechanism.
  • The vital pollen are clumped together in twin masses and are hidden under membranes near the top of the hood.
  • Twin glue-dots are strategically placed to contact the unsuspecting bumblebee's head.
Showy Orchis - Galearis spectabilis
   Incidentally, the orchid flower looks harmless enough doesn't it?  If you were a long-tongued bee and were interested in gathering nectar, wouldn't you land on that inviting white landing pad and extend your tongue into the orchid's well? 
Showy Orchis - Galearis spectabilis pollination
Notice the twin balls convieniently placed at the head of this nectar well (the spur) where the bees will be sure to touch with their head?   Therein lies the "trigger" - a very key part of this pollination system ... those innocent-looking balls are the lumps of sticky glue that will adhere to a visiting bumblebee's head.
hood of the Showy Orchis - Galearis spectabilis
   Take a look at this series of photos of the orchid pollination mechanism in action (keep in mind for demonstrative purposes I used a twig in place of a bee).
   This first orchid photo shows the lip (or landing strip) extending to the right and the lavender hood or helmet partially covering the key components of the pollination mechanism.
pollination mechanism of the Showy Orchis
Can you picture a bumblebee sitting on the orchid's lip and reaching deep into the orchid's spur for some nectar?  Perhaps a twig will make a good imaginary bee. 
pollination mechanism of the Showy Orchis
Remember those innocent-looking twin balls?  Now they have contacted our bee's "head" and their protective covering has released some sticky glue... see the shiny, sticky substance where the twig contacted the balls?  The term for the sticky stuff is "viscidia", and the protective covering is called "bursicles".
   As our "bee" retreats, the sticky viscidia have adhered to its "head" and as a result the pollinia are being removed from their protective membranes.
pollination mechanism of the Showy Orchis - Galearis spectabilis
Here is another photo of the pollinia as they are pulled from their protective bursicles.
pollination mechanism of the Showy Orchis - Galearis spectabilis
Here is a close-up photo of the Showy Orchis hood as the pollinia are further removed from their protective coverings.
pollination mechanism of the Showy Orchis
In this next photo the freshly removed pollinia of the Showy Orchis are nicely displayed - similar to how they would be attached to a real bumblebee.
pollinia of the Showy Orchis
   Now, picture this bumblebee flying to the next orchid with its extra pair of antennae.  It's like a cartoon... see what I mean about this orchid's pollination system reminding me a Rube Goldberg machine?  The orchid's pollination is an elaborate, complex system of interacting parts that effect a commonplace result - the cross-pollination of some small, inconspicuous orchids on the forest floor.
pollinia of the Showy Orchis
   Have no fear, I had our fake bumblebee, with pollinia attached, visit another orchid up the creek.  I hope I affected some cross-pollination like a real bumblebee would have done had it visited this particular Showy Orchis.
Showy Orchis - Galearis spectabilis
We hope a few bumblebees do likewise.

See some more photos of the Showy Orchis in my previous post.

Friday, May 24, 2013

Showy Orchis

   We found this pretty little orchid, the Showy Orchis, growing near a creek.  This orchid could easily go unnoticed as its flowers barely rise above the forest floor.  Each time we see one of these native orchids it's like a little surprise because they are small enough you are almost on top of them before you see them.  Speaking of surprises... the Showy Orchis has a surprise gift for its bumble bee visitors (I'll explain later).
  Here is a photo of the Showy Orchis (Galearis spectabilis) growing under a Maidenhair Fern.
The Showy Orchis has two broad leaves close to the ground and a short, leafy stalk where its lavender and white flowers bloom only inches from the ground.
The Showy Orchis has a lavender-colored hood and a good-sized white lip for its bumblebee landing pad.  Also, there is a long white spur from the back of the flower... this is where the nectar collects.
Isn't the Showy Orchis a lovely orchid?
Have you seen what this orchid does to bees?
   Yes, our native orchids each have a bee-tricking apparatus that functions as part of the complicated orchid pollination process.  The Showy Orchis is no exception, despite its unassuming size and habitat.
   Next up.... a look at the Showy Orchis and its pollination mechanism

Monday, May 20, 2013

Yellow Ladys Slippers On A Pennsylvania Hillside

a lovely native orchid - the Yellow Lady's Slipper (Cypripedium parviflorum)
   There is at least one place in Pennsylvania where the Yellow Lady's Slippers grow like weeds.  Over the weekend, we went on a hike at that spot.... a wooded limestone hillside where these large, yellow, native orchids love to grow.  What fun!
  We noticed the orchids often grew in pairs like the ones in the photo below.
Native orchids - the Yellow Lady's Slipper on a limestone hillside
 The orchids sometimes grew in clusters.
cluster of large yellow orchids

Sometimes the yellow orchids grew singly.   This lone Yellow Lady's Slipper isn't really alone.  I can see about five or six other flowering orchids in the background.  I could see about a dozen of these bright yellow orchids from the spot where I took the picture.
Yellow Lady's Slipper Orchids on a Pennsylvania hillside

   My regular readers know I am fascinated with orchids and the variety of tricks they play on bees.  Each kind of orchid seems to have its own method of bamboozling bees during the pollination process.
  The Yellow Lady's Slipper orchid uses a trap-and-funnel pollination mechanism.  The trap is the pouch, or slipper, of the orchid.
 Yellow Lady's Slipper  (Cypripedium parviflorum)
When a bee (or bumblebee) is attracted to the orchid by the bright yellow color and/or the faint, pleasant smell, it finds a convenient hole where it may expectantly drop into the roomy yellow pouch.
the slipper-shaped bee trap pouch of the Yellow Lady Slipper
 You guessed it!  The yellow pouch is all "puff"... it is an empty, reward-less trap.
 Here is another photo of the orchid's bee trap... doesn't it truly look like a slipper?
the bee trap pouch of the Yellow Lady's Slipper
   The pouch is designed to make escape difficult... at least if the bee tries to fly, or scramble, out of the hole it entered.  Eventually, the bee finds a tunnel to crawl through to exit the orchid.  As the bee navigates the short tunnel, it first get its back "swept" by the stigma for any pollen from a previous Yellow Lady Slipper visit.  Then, right at the exit, a sticky pollinium is stuck to its back for the bee to transport to the next Yellow Lady's Slipper.
Yellow Lady's Slipper pollination mechanism
   Can you picture how that pollination system works by looking at the picture above?  See my post about the Pink Lady's Slipper and my diagram of that orchid's pollination mechanism.  The two orchids use a similar system... the difference is... the Pink Lady Slipper uses more of a trapdoor for an entrance into its trap, while the Yellow Lady Slipper uses what I call a "well".
  I hope some bees repeatedly "fell" for the Yellow Lady Slipper's traps this year.
Yellow Lady's Slipper Orchid
Don't you?

Up next are some little orchids, the Showy Orchis (Galearis spectabilis), that were growing at the bottom of this hill.

Saturday, May 18, 2013

A Few Native Orchids

We had a very successful hike today scouting for native orchids.  We saw three kinds of wild orchids.  This photo shows my son beside a cluster of Yellow Lady's Slippers.
 Yellow Lady's Slippers (Cypripedium parviflorum)
 We were hiking through a rich woods on a limestone hillside.  These knee-high orchids were scattered everywhere...  one here, a few there, a couple more of the yellow orchids right up there!
 Yellow Lady's Slipper (Cypripedium parviflorum)
 I'll post more photos of the Yellow Lady's Slippers (Cypripedium parviflorum) soon... and of course I'll examine their pollination mechanism.

Here is another wild orchid we saw today.  This lovely little orchid is a Showy Orchis (Galearis spectabilis) that was growing under a Maidenhair Fern. 
Showy Orchis (Galearis spectabilis)
 We found plenty of these small orchids growing along a stream... well, high on its banks and on its floodplain.  I'll post about the lavender and white Showy Orchis in the near future.

No, I won't forget to investigate its pollination mechanism.

On the rocky ridge top among the large boulders we saw a number of Pink Lady's Slippers.
Pink Lady's Slipper Orchid
Remember my post about the Pink Lady's Slipper and its pollination mechanism ?

A short hike filled with a variety of bountiful wild orchids.... that's what I call FUN!

Friday, May 17, 2013

Red Trillium Does Threes

When I saw this Red Trillium, I thought of the number three... for some reason.
This post also has something to do with threes.
  1. Three photos of a Red Trillium (Trillium erectum)
  2. Three details about Trilliums
  3. Three hundred Nature Posts.
First photo... notice the Trillium's three maroon-colored petals framed by the three pointed sepals.  Second photo... notice the whorl of three bracts (leaves).
Third photo... you can't see it in this lower resolution photo, but there is a fly on the Trillium's right petal near the center of the flower.  Flies are pollinators of Trilliums - they are attracted to the rotten-smelling flowers.
Yes indeed, this three-themed flower made a great subject for my three hundredth Nature Post, eh?

Monday, May 13, 2013

Mushrooming Among Some Elm Trees

   The other day I was scouting for morels and early orchids in a patch of Elms.  I didn't see any morels but I did see another kind of (reportedly) edible mushrooms.  I watched some slugs happily devouring the scaly tops of these large, saddle-shaped mushrooms.
   Here is a photo of these mushrooms.  They are called Dryad Saddles (Polyporus squamosus).  Some folks call them Grouse Wings.
Dryad Saddle - Polyporus squamosus on elm stump
   Since Dryad Saddles like to grow on Elms, they were plentiful... I was in a large patch of elm trees.  I could have gathered some of these mushrooms for eating, but I didn't think we would enjoy their smell or flavor.  Bill Russell, in his book, Field Guide to the Wild Mushrooms of Pennsylvania And the Mid-atlantic , says, "Some people think the mushroom smells like cucumber or watermelon."
Dryad Saddle mushrooms
 He also says, "Someone with a powerful imagination long ago thought that they would make good riding saddles for fairies and such creatures."
Here is a photo of a Dryad Saddle growing out of a moss-covered fallen log.
Dryad Saddle - Polyporus squamosus
 The underside of the cap of Dryad saddles (Polyporus squamosus) is all pores.
pore surface of a polypore

I took some photos of the slugs feeding on the mushrooms.
slugs eating mushrooms
 Large or small, the slugs seem to have a good life with all these large mushrooms fruiting right now.
slugs feeding on mushrooms
 In the next photo the slug has "slimed" it way up a plant stem and is stretching over to "nibble" on the edge of a Dryad Saddle.  That is, if a slug can "nibble" with its radula.
slug feeding on mushroom
 Not all of the fruiting bodies were mature.  I saw some very young Dryad Saddles.
Young Dryad Saddle mushroom
I guess that means the slugs can feast for a little while longer before they have to nibble on some other fungi.

Friday, May 10, 2013

What Happened In The Willows, Part Four

   The willows by the roadside were an unplanned stop, but I found much to keep my attention right there.  When I spotted the little green bee covered with oil beetle larvae, I began to search for those larvae (triungulins) on the tips of branches and stems where they might be waiting in ambush for bees.  I wasn't very successful in finding clusters of those waiting larvae, but I did see an amazing variety of insects on the tips of stems.  Here's a compilation of some of what I saw.
 The most common insects I saw on stem tips were click beetles. 
Click beetle on branch tip
I saw so many just hanging out there that I surmised that these were female click beetles calling males by emitting attracting chemicals.
  Here is a photo of another click beetle perched on a leaf tip.  There are a couple of small shiny black beetles off to the side.  I suspect they are some kind of leaf beetle.
 Here's another photo of a leaf beetle (Paria sp).
Leaf beetle - Paria sp

 Oh, who would expect to find a sleeping bee in the late afternoon?  While many bees were busy visiting Spring Beauties and Bluebells, this Cuckoo Bee was hanging on the tip of a stem by its jaws... sleeping.
Cuckoo bee in sleeping position
 See another post where I have more photos of a Cuckoo Bee hanging by its jaws in this unusual sleeping posture.
   Here is an assassin bug nymph feeding on its prey.  Was the fly "sleeping" on the tip of the leaves when it was ambushed or did it land too close to the nymph?  Perhaps the nymph was well camouflaged on the buds when the fly happened by. 
Assassin bug with prey

This damselfly was well hidden as it rested on some unfurling buds.

As you can see, I saw all kinds of "stuff" while looking for those elusive oil beetle larvae.  I'm not done yet! 
   Look at this incredible sight... A male Dance Fly clinging to a branch with two legs. With the rest of his legs he's hanging onto his mate and her nupital gift.  All the while he's using his head as a prop.
Pair of mating dance flies with nupital gift
 Ouch!  You would think he has a headache. Or at the least, he might be damaging some of his navigational equipment.
pair of mating dance flies with prey
 Notice that the prey the female is feeding on is another dance fly.  The male dance fly would have caught this unfortunate dance fly and presented it to the female as a nupital gift.
pair of mating dance flies holding prey
 She seems pleased with the gift.

Reminds me of another gift.... if you call writing a masterpiece a gift.  
  Whenever I see a Mayfly, I think of Benjamin Franklin's "Soliloquy of an Ephemera".
Basically, in a letter to a French Lady, Ben wrote of overhearing the conversation of some Mayflies.  He says, "... I turned my head from them to an old grey headed one, who was single on another leaf, and talking to himself. Being amused with his soliloquy, I put it down in writing....".
That soliloquy ("overheard" by Ben) is a brilliant piece of writing about Ephemera.
Mayflies... an ephemeral marvel of May.

   Well, that's some of what I saw as a result of stopping at the willow patch.  May I remind you that someone had taken my planned parking spot... otherwise, I may not have seen what I did in the willows that resulted in this series of posts.
What Happened In The Willows, Part One
What Happened In The Willows, Part Two
What Happened In The Willows, Part Three