Green-and-Gold (Chrysogonum virginianum)

Living in southeastern Ohio for the last handful of years has really allowed your blogger the opportunity to explore and familiarize himself with a landscape quite different from his childhood base of west-central Ohio.  As an adopted son of the hills and hollers, I feel just as at home immersed in the unglaciated Allegheny Plateau as I do back on the Wisconsin till plains.  The scenery and flora/fauna has yet to grow old or stale and still has plenty of surprises and welcome discoveries to share.

Hillside patch of green-and-gold in full bloom

Earlier this week I had the pleasure of finally making the acquaintance of a southeast Ohio exclusive that has sat unchecked on the life list since my initial move to the region.  Green-and-gold (Chrysogonum virginianum) is also known by the common names of golden knees or goldenstar and is one of the most striking yellow wildflowers I've had the pleasure of seeing with my own eyes.

Green-and-gold (Chrysogonum virginianum)

Green-and-gold is a state-threatened species here in Ohio and is only known from extant populations in Athens and Washington counties.  This particular population was located in rural Washington county near the Ohio River on a steep roadside embankment under a canopy of white oak, red oak, sugar maple, yellow buckeye, white ash, flowering dogwood, and redbud with a scattering of your typical spring ephemerals.

Closer look at the green-and-gold's flowers

If you take a close look at the center of the "flower" expecting to see a pistil and flurry of stamens, you will actually see a composite flower head with numerous disc flowers exerting their own individual stigmas and anthers. Despite appearing as a marsh marigold-like plant from a distance, green-and-gold is actually a spring-blooming member of the aster or composite family (Asteraceae).  It also happens to be the only Ohio composite containing (typically) five yellow ray flowers.

Green-and-gold (Chrysogonum virginianum)

Some may recognize this as a plant they have in their landscaping or wildflower garden as it is a popular and frequently used ground-cover for its ability to spread rather quickly by rhizomes.  It does best when you can imitate its favored conditions in the wild of moist, rich, and acidic soils in partial to full shade.

Chrysogonum virginianum North American distribution (courtesy BONAP)

Looking at a map of its natural distribution throughout eastern North America, you can see it just barely makes it into our state via the southeast.  It occurs predominately east of the Appalachians in the Piedmont and along the coastal plains of the Atlantic and Gulf states.  The species has been assigned two varieties split by a more northern or southern distribution.  Following this treatment, Ohio's material belongs to var. virginianum while the southern Piedmont and coastal plains belongs to var. australe.

Zoomed in view of receptacle and disc flowers

View of the attractive, hairy green foliage

A macro shot shows the details of the aster family's characteristic receptacle and numerous disc flowers in the photograph above left.  What look like petals on a composite flower are actually called ray flowers and bear fertile reproductive parts as well. The basal leaves of green-and-gold have an aesthetic appeal of their own with densely fuzzy petioles and crinkled margins.  I can easily see and understand why this plant would be a welcome addition in anyone's landscaping and hope to utilize it someday in the future myself.

Hillside patch of green-and-gold in full bloom

While photographing and admiring the golden-knees, I found myself frequently pausing to close my eyes and soak in the surrounding sounds of the back country road's environment.  The swift sounds of rushing water in a nearby rain-swollen stream were intermittently interrupted with the sweet calls of dueling cerulean warblers overhead accented with American redstarts, hooded warblers, and wood thrush as well.  I even managed to get my year's first ruby-throated hummingbird as two tiny blurs gave an unmistakable chitter as they buzzed by.

Hillside patch of green-and-gold in full bloom

While many plants may find a roadside existence to be stressful and worrisome, I believe it may be a saving grace for this specific population.  Competition from surrounding/taller vegetation and natural succession can choke out this species quite easily or at least reduce it to non-flowering vegetative material due to too much shade but seasonal cutting and mowing by the township or perhaps a local resident seems to keep this embankment relatively free and clear of encroaching woody vegetation.

The hillside of flowering green-and-gold proved to be worth the wait as I would be hard pressed to find another spring wildflower graced with such a rich golden color.  It's my hope this site will continue to see good fortune and be something I can return to in future springs to enjoy their enlightening charm.

Missouri Ironweed (Vernonia missurica)

As I become a more experienced and knowledgeable botanist it's hard not to play favorites when it comes to certain families and genera of vascular plants.  By now you all know of my passion and deep-rooted love for the wild orchids (Orchidaceae), which more than likely would be placed first on my list of most admired.  There are plenty more that keep those rare and delicate plants company on that list, such as the Ironweeds (Vernonia spp.).  They aren't the showiest nor the rarest species to be found in our wide array of native flora but there's just something about them that really directs my focus to understanding and studying them.

About a week ago I published a post starting my treatment on the Vernonia genus in Ohio and its four members.  It can be found by clicking the link HERE for those interested in getting a grasp on the Tall Ironweed (V. gigantea) and the Prairie Ironweed (V. fasciculata).  I mentioned in that post that I would be attempting to collect, photograph and study the two remaining species that have been recorded from our state.  A difficult task when taking into consideration the rarity of the latter two species; Missouri Ironweed (V. missurica) and New York Ironweed (V. noveboracensis) inside Ohio's borders.  This past Sunday I made the journey to Daviess County in southwestern Indiana with high hopes of finding the third species of Ironweed I'd like to discuss, the Missouri Ironweed (V. missurica).

Missouri Ironweed in native habitat

Flowehead(s) of Missouri Ironweed

My destination was one of the areas most pristine and diverse nature preserves in the state known as Prairie Creek Barrens.  A large expanse of wet prairie containing numerous rare and fascinating plant species has survived years of land abuse from the surrounding agricultural landscape to remain intact and well managed to keep the rare ecosystem thriving.  I plan on doing a separate post about my experiences with the other gorgeous flora of the preserve but my focus was directed at the tall wands of purple swaying in the morning breezes.  At first glance Missouri Ironweed looks almost identical to the much more common Tall Ironweed.  As I mentioned in the previous Ironweed post, habitat differentiation goes out the window with these species as they all prefer wet to moist expanses of open ground with plenty of sunlight and commonly grow together.  In fact, there was Tall Ironweed to be found growing amongst the Missouri in Prairie Creek Barrens.

Taking a look at the corymb of flowerheads it's still not too easy to differentiate from the more common Tall Ironweed.  Both have very similar rayless disk flowers of a magenta color, tightly overlapped phyllaries that look very much alike as is the spacing and density of the flowerheads.  The number of individual disk flowers per flowerhead can be used to separate the two.  Missouri tends to have more, with an average over 30, while Tall Ironweed typically has a number less than 30.  A close glance at the inflorescence's stem or peduncle can begin to clear the air.  On Tall Ironweed the stem is generally finely pubescent if not a bit more smooth and glabrous.  On Missouri Ironweed the stem is noticeable hairy with a dense covering of wooly hairs.  Hair is the name of the game with Missouri Ironweed as you'll come to see when looking at the rest of the plant.

Glancing at the distribution map for this species it's pretty evident this species is most common in the Mississippi river region, with some disjunct populations to the east and west.  Ohio lies at the eastern edge of the range where it's only known to occur in the Oak Openings area (Lucas County) as well as a remnant tall grass prairie patch along the railroad (Clark County).  There have also been recorded collections of a natural hybrid between Missouri and Tall Ironweed in several northwestern counties.  This has lead to some botanists and authors to question the true genetic integrity of Missouri Ironweed in Ohio.  Having never seen Ohio's alleged true V. missurica I really have no opinion in the matter but can understand the skeptical outlook of the doubting minds.

Missouri Ironweed's leaves

heavy pubescence on underside of leaf

The best means to tell the two nearly identical Tall and Missouri Ironweeds apart is to take a look at the stem and the undersides of the leaves, especially at the petiole.  The leaves are arranged alternately and lanceolate in shape with serrated margins like all other Ohio Vernonia's.  Where the differences begin is very noticeable and heavy pubescence of the undersides of the leaves, especially at the petiole.  The numerous small hairs run along the veins and give off a crystalline look to the emerald leaves.  If you remember the picture of the underside of the Tall Ironweed's leaves they lack the obvious pubescence with just a very conservative scattering of hairs, if any at all.

Missouri Ironweed leaves

Missouri Ironweed leaves

The pictures above really drive the nail home at just how hairy the undersides of the Missouri Ironweed's leaves are.  From a ways back the leaves give off a silvery-green sheen from all the hairs.  The stem is another great place to look for the persistence of hairs on the Missouri Ironweed.  Tall Ironweed's stems can range from glabrous to finely pubescent but rarely anything like the display of hairs the Missouri Ironweed puts on.

Missouri Ironweed's stem

Magenta flowerheads of the Ironweed

In my experience the hairs on the stems of Missouri Ironweed are a whitish-clear color while the hairs of the Tall Ironweed are a purplish-brown color.  I've never read or seen where this is a definitive difference and used in the genera's keys, just an observation I've made in my careful examination and breaking down of the species.  I hope to make a trip down into Kentucky to get the fourth and final Ohio Vernonia, the New York Ironweed (V. noveboracensis) that I can add to this treatment and breakdown of the species.  New York Ironweed was only collected once in Ohio over a century ago and has since been marked as extirpated.  It's very distinct phyllaries end in a long, thread-like hair that can quickly separate itself from the rest of the Ironweed's.  Once again I'm sure this wasn't the most fun post for the majority of the faithful readers but it's been fun for me to delve into this genera and really get a hands on understanding of what sets these beautiful and unique plants apart.  Until next time!

Prairie Ironweed (Vernonia fasciculata)

August already!?  I swear I was enjoying and photographing Trillium and Hepaticas just the other day.  My how time flies when you are having fun!  If you've spent much time outside and kept your eyes focused in on what's in bloom out there you may have noticed the transition that's currently happening.  June and July's summer flowers have given way to the onslaught of those more synonymous with late summer and fall.  Sunflowers (Helianthus spp.), Coneflowers (Rudbeckia spp.), Blazing Stars (Liatris spp.) and other members of Asteraceae are coming to life and coloring our world with yellows, oranges, pinks and purples.  Speaking of purple flowers, a fun and pretty genera of plants is just starting to really come on in Ohio; the Ironweeds (Vernonia spp.).

The Ironweed's are easy to distinguish from everything else by their tall and straight, unbraching stems topped with a beautiful panicle of purple-pink flowerheads.  Despite having four different native species in Ohio, 99% of the time what you see and find is the Common or Tall Ironweed (V. gigantea).  Along the road, in old fields and meadows, along streams and woodland margins; the stuff grows just about every place that has lots of sun and moist soils.  In fact it can almost be considered by some as a bit of an obnoxious weed despite being indigenous to the area.  The other three species are all much, much more rare in Ohio and in fact all are state listed as either threatened, endangered or even believed to be extirpated as in the case of the New York Ironweed (V. noveboracensis), which was only collected once in Ohio in Gallia County well over a century ago.  Missouri Ironweed (V. missurica) is endangered and only currently known from Clark and Lucas counties.  Today's focus is on the fourth species, Smooth or Prairie Ironweed (V. fasciculata) and how to distinguish this rarity from the much more common Tall Ironweed.

Prairie Ironweed is a much more western, Great Plains species of Vernonia that just slips into Ohio at the eastern fringe of its natural distribution.  Listed as threatened in Ohio, it occurs scattered throughout the western half of the state in areas of wet prairie.  Prairie Ironweed's habitat preference is open, wet situations with plenty of sunlight, especially in more deep and rich soils.  It can occasionally be found in marshes as well.  The population I know of grows in a wet ditch along a select stretch of bike path in eastern Clark County.  So let's take a look this versus the common V. gigantea.

Vernonia gigantea flowerheads

Vernonia fasciculata flowerheads

Considering both species will and do grow side by side, habitat differentiation for these plants goes right out the window.  In fact almost all the Ironweeds are known to naturally hybridize with each other, making the I.D. factor difficulty go up tenfold.  Height is the first thing that can help to separate the two.  Tall Ironweed gets its name for a reason, sometimes growing to nearly 7' tall.  Prairie Ironweed rarely gets 5' tall and is generally more in the 2-4' range.  The panicle of flowerheads can also help as well.  As you can see on the left picture above, Tall Ironweed's panicle is more open with spacing in-between the flowerheads while Prairie Ironweed (on the right) is bunched up with almost all the flowerheads densely compacted.  This characteristic can be seen in better detail further down.

V. gigantea inflorescence

V. fasciculata inflorescence

Beginning to take a closer look at the individual inflorescences it can be seen that both differ in the shape, size and color of their phyllaries.  Phyllaries are the little leaf-like bracts that look like little shingles on the involcure which holds all the individual disk flowers together.  On Tall Ironweed the phyllaries are smaller, darker colored (usually a purplish-green) and end in a sharp point.  With Prairie Ironweed the phyllaries are much larger, a distinct mixture of purple and green and are more blunt at the end.

V. gigantea's hairy stem

V. fasciculata's smooth stem

The presence or lack of hairs on the stem can also be used as a distinguishing factor but is one of the weakest areas due to the high level of variability within each species.  Generally Tall Ironweed's stem is covered in a pubescence of fuzzy hairs especially the further down the stem you go.  Prairie Ironweed's stem is almost always glabrous, showing no signs of hair.  I've seen plenty of Tall Ironweed with almost completely smooth stems and hardly any hairs so this is a pretty weak feature to put much faith in.

V. gigantea inflorescence

V. fasciculata inflorescence

Above are a couple more shots of each species flowerheads.  In these pictures it can be seen more clearly just how spaced apart the flowerheads are in the Tall Ironweed against the much more clustered and tightly bunched Prairie Ironweed's.

V. gigantea leaves

V. fasciculata leaves

All members of the Vernonia genera in Ohio have elongated and lance-shaped leaves with serrated margins and alternately arranged but there are varying differences within each species.  The leaves of Tall Ironweed are on average 2-2.5" wide and up to 10" long.  Prairie Ironweed's are significantly shorter and narrower, only averaging 5" long and 1/2" wide.  I've read where Prairie Ironweed leaves undersides can exhibit a habit of pitting; more or less a lot of dark dots.  None of the plants I found had leaves showing that feature but it can be used as an I.D. feature as well.

Prairie on L, Tall on R

Tall leaf on L, Prairie leaf on R

Above are some images comparing the leaves and individual inflorescences/phyllaries of each species side by side.  You can really begin to grasp the size and shape difference between the leaves and especially in the phyllaries.  Sometimes it can be hard to differentiate between similar species without having both to compare at each others side.  Below is another shot of each plants respective phyllaries.  I think the differences can really begin to stick out once you spend enough time comparing the two together.

V. gigantea phyllaries

V. fasciculata phyllaries

Both species are quite pretty to my eyes, coloring the green meadows and fields with tall wands of purple that are covered in all types of butterflies, moths and bees/flies.  While you are not likely to run into much Prairie Ironweed in our state I am just drawn to certain species of plants that can be fun to separate and study.  I plan on making a trip to southern and southwestern Kentucky to study and photograph the other two species of native Ironweeds to complete this treatment.  Perhaps not my most interesting topic ever but it was fun for me and hopefully for those wanting to separate just one of those tricky Asteraceae family members.