Wednesday, July 13, 2011

Another helping of Botany, anyone?

Purple Coneflower, Echinacea purpurea

The Midwest Native Plant Symposium brought together a combination of botanical experts, local native plant vendors and plant/nature enthusiasts for a weekend of wild activities of all sorts. Mornings began with bird walks, just as the sun was making its way onto the sprawling greenscape of Mount Saint John. As anyone with an interest in our birds or bugs soon discovers, they owe their existence to an intimate connection with our native plants as well, which provide that broad base to the food chain, determining and supporting all life above it. Nights wrapped up with moonlit jaunts along the wooded trails or between plots of prairie in search of insects roused as darkness fell--assorted crickets, beetles, moths and katydids. And between those outdoor, exploratory pursuits, a choice of classroom sessions covered everything from Ohio’s champion trees to the tiniest parts of a flower.

A dinner plate scattered with flowers and a hand lens wrapped in its long, black cord waited on each chair in David Brandenburg’s classroom. I had met Dr. Brandenburg before and carry his invaluable guide to wildflowers wherever I go. This morning, we would take a closer look at the Aster family—look more deeply into the largest family of flowering plants, easily recognized by having an inflorescence (flower head) composed of many florets (smaller flowers, each with distinct characteristics). Easily recognized, yes--but perhaps not so easily understood.
There’s a lot going on beyond what the untrained eye can see while watching from the garden’s edge. Breaking open those beautiful flower heads and jumping in with a hand lens is the only way even the experts are able to sort it all out!

Dr. David Brandenburg serves up a plateful of Asters

Some of the most common and well-known flowers belong to the Aster family, Asteraceae (or Compositae)--daisies, dandelions, and thistles—and even to the naked eye, their differences are pretty easy to see. What gives these “flowers” their distinctly recognizable profiles, however, are the tiny florets composing each inflorescence—3 types, which, when arranged in different combinations, create 3 very different looking flower heads.

Beneath the hand lens, the familiar flower parts we all learned in grade school suddenly appear on the face of the daisy. Packed by the hundreds into its center, there are small flowers, each with a tube of 5 united yellow petals and a column of fused anthers. A hair-like style in the center of each emerges and splits into two delicate branches. Each of these minute florets, described as tubular or regular, is called a disc flower and possesses both male and female parts.
But, around the daisy’s white edge, the florets look very different. Strap-like or irregular, these small flowers have 5 united petals, as well, though they projects as a unit only to one side. They are known as ray flowers, which may be female (as in a daisy) or, in some species, neutral, acting only as a flag to attract a pollinator to other non-sterile florets within the flower head. (sunflowers)
Ligulate florets, like disc florets, contain both male and female flower parts, the column of anthers and branched style, but, like ray florets, have fused petals appearing as a single strap.

Combinations of florets create the 3 basic flower heads. The daisy, a radiate head, is made up of a field of disc flowers surrounded by a ring of ray flowers. Thistles are composed of disc flowers entirely and illustrate the discoid head. While dandelions, composed entirely of ligulate flowers, are said to have a ligulate head.

Fen Indian-Plantain, Arnoglossum plantagineum

It's in the Aster family--look closely at the tiny florets making up each 5-part flower! The photo above shows each floret's petals still tightly closed.
Click photos for a closer look!

Now, the fine white petals have curled back to reveal the columns of anthers (those brown things sticking out). Some even show the 2-part styles which have emerged through the columns to tower above them. The orange coloring at the anthers' tips is pollen that is pushed out through the top of the column by the style from below as it lengthens and grows within the column. Cool, huh? And, oh, so tiny!

flowers have passed

So,... what of all these technical terms? Is it simply to sound smart and impress others with a newly-learned, secret language?

Nope, not at all.
Take one peek into any serious plant manual, and you’ll soon understand the importance of getting a grasp on botanical language. With over 22,000 species of asters alone worldwide, subtle differences separate similar species. Keys are written and flowers described with consistent terms to eliminate confusion.
Without concise language, navigating a dichotomous key would be like attempting to follow a roadmap through New York City—one without any street names.
In no time at all, everyone would be lost.

Jim McCormac, our trip leader, quizzes us about the flower heads of asters

The next day, in a trip to Cedar Bog, the classroom language was reinforced in the field. Cedar Bog is far more than a collection of asters, though, with scores of rare or endangered plants at every turn along the 1-mile boardwalk. And, as you’d expect in an area so botanically diverse, we found far more than native plants.

Steve McKee and Cheryl Harner assist from the back

It all starts with the native plants, though.
And our understanding of them and their significance to everything else.

Cheryl Harner and Derek Hennen pause to enjoy the cool breeze from the shade of Northern White Cedars

For contrast, a Michigan Lily, Lilium michiganense--
NOT an aster, no hand lens needed here!

The National Wildlife Federation
Field Guide to Wildflowers of North America
by David M. Brandenburg

Thank you, David, for tweaking this explanation
and straightening out all these florets in my mind!

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Endment said...

Fun post and I learned a lot - thanks so much for sharing!!!

Patricia Lichen said...

Love the photo of everyone peering into their lenses!

KaHolly said...

Love this post!!! So thorough. I'm envious of your experience!! Someday I hope to be able to take advantage of a similar experience. (Our asters haven't started to bloom yet.) Looks like you had a great time!! ~karen

Q said...

Thank you for taking us along on your aster adventure. Wow, a wonderful workshop.

Mike Whittemore said...

Wow what an opportunity! I love Ohio for its richness and passion for nature. I'm interning in ND and met many Ohioans on the Prairie Potholes Birding Fest. We far outnumbered the other states. I'm definitely proud to be a resident and to have the opportunity to be around such cool and informational events like this and Flora Quest! I'll have to sign up for this next year!

Mary Ann said...

wonderful post Nina! As usual, I learned a lot and it reinforced my desire to attend next time. Thanks!

nina at Nature Remains. said...

Mike, you're not alone in that observation.
I've heard others' remarks about, not only how many renowned experts we have in the state of Ohio, but an appreciation for their willingness to share their knowledge during weekends and workshops just like this one.
I never pass by an opportunity to tag along--there's no better way to learn this stuff, than at the elbow of the ones who write the manuals!

Randy Lakes said...

Nina, Once again it was a pleasure to hit the trails with you. However I thought for sure there would be a post by now of the perils of the early instars of Copiphorinae (coneheaded katydids) :-)

Seriously, keep up the great work both in prose and photography!!!

nina at Nature Remains. said...

Good to see you, too, Randy!
I've added another article, beside flashlight, to next year's packing list for nighttime hikes--gloves!

Deborah Carr said...

Wow...what intriguing information! How did you take it all in? It reminded me of a short video I watched that took us from the milky way, to our solar system, to Earth, to a single cell in a tree on that earth...all to illustrate the intricacy of parts that make up the whole. What we think we see, is actually the sum of so much more than what we can imagine.

The aster's beauty is certainly more than skin deep!

Guy said...

Hi Nina

A great post and very informative. I can see I will have to get a hand lens and a grasp of some terms to carry with me on some of my nature walks.

Thanks Guy

Mist Eliminator said...

What a lovely post... Really interesting...