Sunday, September 27, 2009

Finis coronat opus Gentiana!

The end crowns the work - may the last be the best! The glorious time of Gentians is upon us - another growing season putting on its final show. The beauty of Gentians is enhanced by the lovely places they inhabit, the splendor of the autum sky, and the magic of falling leaves, among many other good things. All photos from Lake County, Indiana, 9-27-09.
"Blue thou art, intensely blue;
Flower, whence came thy dazzling hue?" James Montgomery

Prairie Gentian - Gentiana puberulenta

Fringed Gentian - Gentianopsis crinita

Bottle Gentian - Gentiana andrewsii

Soapwort Gentian - Gentiana saponaria

Tuesday, September 22, 2009

How's About A Plant Quiz? - We've Got A Winner!

I recently posted this photo as a plant quiz...

Keith wasn't fooled by my shenanigans. These are the bulblets of the roots of Dicentra cucullaria, Dutchman's Breeches. These bulblets go dormant after the plant goes to fruit, and they remain dormant until fall. The beginning stages of leaves and flower buds are then formed underground. These primordial leaves and flower buds remain dormant until the spring, when they emerge from the mesic forest floor.

Dicentra cucullaria

There is a spectacular photo of a Dicentra cucullaria plant, including flower, leaves, and root with bulblets on flickr that you can access by clicking here.

Keith mentioned the bulblets of Dicentra canadensis looking similar to those in my quiz but being more round and more yellow-orange. That's exactly right, and a photo of these bulblets is shown above. Some botanists claim to be able to distinguish between these two closely related species based on the color of the undersides of the leaves... if you're ever in doubt, just clear off a little soil and check out the bulblets to tell for sure which species you are dealing with.

Dicentra canadensis

Thursday, September 17, 2009

Fringed Gentians of the Northeastern United States

Late summer brings on the charismatic blues of fringed gentians in calcareous soils throughout the northeastern United States. I have recently spoken with several people who have confused our two species of Gentianopsis. It's certainly easy to confuse these two, as they are very similar, and intermediates between the two species have been observed. In fact, in looking through some of my old photos, I found at least one that I think I misidentified many years ago. With this post, I hope to clear up some of the confusion.

Sometimes treated as a single genus (Gentiana), the gentians in the northeastern United States are taxonomically split by most authors into three genera: Gentiana, Gentianella, and Gentianopsis. Before I get to the fringed gentians, let's look at how the three genera, in the strict sense, differ.

The photograph above shows an open flower of Gentiana saponaria. The flowers of this species are usually more closed than this, but this photo nicely shows one of the important characteristics of the genus Gentiana when separating it from Gentianella and Gentianopsis. Between the corolla lobes, you will see membranaceous appendages. Gentiana, sensu stricto, has teeth, appendages, or plaits between the corolla lobes, while Gentianella and Gentianopsis lack this character. Also, members of the genus Gentiana are perennial, while those of the genera Gentianella and Gentianopsis are annual or biennial.

Gentianella amarella is shown in the photograph above. As stated previously, members of the genera Gentianella and Gentianopsis lack the appendages between the corolla lobes that are present in members of the genus Gentiana. To distinguish Gentianella from Gentianopsis, look at the corolla lobes. Gentianella does not have fringed corolla lobes, while the corolla lobes of Gentianopsis are fringed along the sides and often around the top.

You can see in the photograph directly above and those below that the corolla lobes are conspicuously fringed, so all of these photos show plants in the genus Gentianopsis. The photograph above shows Gentianopsis crinita, Fringed Gentian. The photograph quality is poor, but you can see that the corolla lobes are fringed across the top and along the sides with long (2-6 mm) linear segments. You can also see broad, lance-ovate leaves (often more than 1 cm wide)characteristic of this species.

Above is a close-up of the flower of Gentianopsis procera, Lesser Fringed Gentian. Notice the long, linear fringes on the sides of the corolla lobes, but the short (less than 2 mm), irregular, broad-based fringes along the top of the corolla lobes. In the photograph below, you can see the vegetative distinguishing character between the two species of Gentianopsis. In Gentianopsis procera, the upper leaves are linear or very narrowly lanceolate (often less than 1 cm wide).

Now get out there and admire these cerulean marvels!

Wednesday, September 9, 2009

Virginia Creeper / Woodbine

Many people would look at the two photographs below and call both plants Virginia Creeper or Woodbine, Parthenocissus quinquefolia, without as much as a second thought. But let's take a closer look. Below, I will explain how these two plants can be morphologically separated into two distinct species.

The plant in the photograph above is Parthenocissus quinquefolia, while that in the photograph below is P. inserta (which is treated as a synonym of P. vitacea by some authors, though the nomenclature of these two is quite confusing).

One thing to notice is that the leaflets of P. inserta are more shiny above than those of P. quinquefolia, which often appear dull on the upper surface.

Looking at the undersides of the leaflets, those of P. quinquefolia (above) are almost always pubescent, while those of P. inserta (below) are more often glabrous. There is, however, a rare hirtellous form of P. inserta known as P. inserta f. dubia.

Another part of the plant to check is the junction of the petiolules with the petiole.

In P. quinquefolia (above), this junction is also pubescent; in P. inserta (below), the junction is glabrous.

Growth habit is yet another way to distinguish between these two similar species.

Parthenocissus quinquefolia (above) is often high climbing, but it can also be found growing at ground level. Parthenocissus inserta (below), however, sprawls over the ground, structures, or other vegetation.

The reason for this difference in habit is all in the tendrils...

The tendrils of P. quinquefolia (above) have several branches that end in dilated adhesive discs, which are used to attach to vegetation or structures, allowing the plant to climb. Those of P. inserta (below), however, have few branches and no adhesive discs, and it therefore does not have the ability to climb the way that P. quinquefolia does.

Finally, if you are lucky enough to have flowers or fruit, the distinction between these two species is simple. However, as Swink and Wilhelm point out in Plants of the Chicago Region, P. quinquefolia rarely produces fruit, while P. inserta produces fruit routinely.

As you can see in the photograph above, the inflorescence of P. quinquefolia has a distinct central axis, with 25-200 flowers/fruit in panicled groups of cymes. The inflorescence of P. inserta (below), however, is dichotomously branched and therefore does not have a central axis. It most often has 10-60 flowers/fruit per inflorescence. The fruit of P. quinquefolia are a bit smaller in diameter than those of P. inserta, as well.

It's as easy as that. There is no longer an excuse for lumping all members of the Vitaceae with five palmate leaflets into P. quinquefolia. Now that you can distinguish between mature plants of Parthenocissus, be sure to check The Vasculum to see how to determine the difference between Parthenocissus and Vitis in the cotyledon stage.

Tuesday, September 8, 2009

Another Plant Quiz

Good call Mary! Diarrhena americana it is - American Beak Grass, or Beak Grain. This uncommon, native grass is easiest to locate in late fall when the entire plant turns bright orange, after the surrounding vegetation thins out. It is well known for holding on to last year's grain well into the following spring. I have always thought it looks remarkably like a Carex, superficially at least.
Both photos are rejects, but they are interesting because I never saw the Crane Fly until I viewed them on the computer. Photographed on sandy alluvium in relatively deep shade, slightly elevated above a woodland stream.

Saturday, September 5, 2009

Plant Quiz - Elephantopus carolinianus

Habitat: old field, shady, lower on a slope, SE Indiana (Fayette County)
Any help?

Answer - Elephantopus carolinianus. Good job, Scott. I had never seen this flower before. Apparently, the florets are considered to be disc flowers, not ray flowers.

Gentian Feevah!

With the sudden interest in gentians (what timing!); here is Gentiana linearis photographed in southern Vermont (8/18/09), where it is considered rare. First time seeing it: it is found only in the U.P. in Michigan (4 counties as of this summer thanks to the illustrious Bradford Slaughter). Looks a heck of a lot like G. andrewsii (incidentally also rare in VT) to me, the main difference in G&C's key being the leaves and are not "scabrous-ciliolate" (at least not at 16X).

Friday, September 4, 2009

Gentiana rubricaulis

While working in Superior, Wisconsin a few weeks ago, we came across a gentian that I had never seen before, with dull grayish-blue closed flowers and a reddish stem. Upon running the plant through a key, we determined that we had found Gentiana rubricaulis, Red-stemmed Gentian.

Gentiana rubricaulis differs from similar species such as G. andrewsii and G. saponaria in having smooth-margined leaves and calyx lobes (as opposed to leaves and calyx lobes with ciliate margins). In addition, the plaits between the corolla lobes in G. andrewsii are longer than the lobes, while those in G. rubricaulis are shorter than the corolla lobes. Another important feature used to distinguish G. rubricaulis from similar species is that the the calyces and lower portion of the flowers are usually sunken within the involucral leaves. Finally, the leaves of this gentian are a lighter green color than those of most other members of the genus.

Sometimes referred to as Great Lakes Gentian, the distribution of G. rubricaulis is primarily centered around the Great Lakes; it is known only from four states (Minnesota, Wisconsin, Michigan, and Maine) and three provinces (Manitoba, Ontario, and New Brunswick) in North America. With an affinity for alkaline conditions, G. rubricaulis can be found in sedge meadows, bogs, fens, alder thickets, and coniferous swamps. The closed flowers are pollinated when bumblebees force them open in search of nectar and pollen.

The genus Gentiana was named after Gentius, the King of Illyria, who discovered that the roots of some members of the genus could be used to treat malaria. Rubricaulis is Latin for red stem.