Like a Marble, or an Eye

More small blue things from May. Between travel and rain I haven’t had the opportunity to go hunting in Maryland for several weeks now.

This annual is truly one of my favorites, and I make a point of hunting for it every year. Venus’ looking glass (Triodanis perfoliata) likes poor soils; look for it in open rocky or sandy places.

 

 

I have been having so much fun shooting with The Beast (70-200mm lens). Just look at the sparkle on those petals!

 

 

 

This is a species of Sisyrinchium, probably S. angustifolium though I can’t be sure. Blue-eyed grass is the common name, and indeed the leaves are grass-like. It’s in the iris family.

 

And speaking of irises, the ones I obsessed over last year are going strong. The ones along the canal are, anyway. The ones in the vernal pool are growing like crazy but I haven’t seen flowers on them yet.

I wish I had some new pictures of Baptisia australis to share, but honestly I haven’t even been out to shoot them. We’ve had tremendous amounts of (badly needed) rain in recent weeks, and I know that part of the river well enough to know that one stand is under water. Here’s what they looked like budding up in early May this year.


The other stand I’m sure is fine, but the channel I need to cross to get at them is flooded, too. Here’s a picture from last year.

That’s More Like It

Remember those irises that I obsessed about last summer? One of the stands is located in a vernal pool that’s been dry for two years, but we’ve finally gotten enough rain for the pool to recharge. This will keep me from getting close up shots when they bloom in about a month, but the plants are looking really happy now.

Winter Blues

Virginia bluebells carpeting a Potomac River floodplain last spring

Happy new year! I’m back, after a truly epic case of writer’s block. Not that there’s anything blooming to write about yet, since the local wildflower show won’t be starting until late February at the earliest, more likely mid-March if this winter stays as cold as it has been. Which has been pretty darn cold compared to the last five years or so, but not that unusual compared to, say, the past 50 years.

At any rate I’m fighting the winter blues by recalling blue flowers I found this past year. Here are a few from the Maryland Piedmont.

Anemone americana (formerly Hepatica nobilis var obtusa; round-lobed hepatica; Ranunculaceae)
This species is hibernal – the basal rosette of leaves will be out right now, though likely hidden under leaf litter. The leaves will die back as the small flowers appear just an inch or two off the ground. In the Piedmont I’ve seen them as early as early March and as late as mid April, though they don’t bloom for long; they just seem highly variable about when they start blooming.

Baptisia australis (wild blue indigo; Fabaceae)
This species is found primarily in prairies, but also occurs in some prairie-like habitats east of the Appalachians, including bedrock terraces in the Potomac gorge. According to the Maryland DNR’s new RTE list, there are only a few populations here. It’s listed S2/Threatened. Finding it is a real treat.

Clitoria mariana (Atlantic pigeonwings, butterfly pea; Fabaceae)
I’ve only seen this in a few places, always in rocky areas in a bit of shade, and there’s never much of it. Start looking in mid June.

 

 

Conoclinium coelestinum (formerly Eupatorium coelestinum; blue mistflower; Asteraceae)
This medium-height plant blooms from June through September in wet soils next to the Potomac River – not right on the banks, but close by.

 

Houstonia caeulea (azure bluet, little bluet, Quaker ladies; Rubiaceae)
These tiny flowers bloom en masse in April and May in moist, rocky soils in open wooded areas. Sometimes you’ll see only a few, but other times you may find them carpeting a meadow. They are really tricky to photograph up close, as even the slightest breeze sets them in motion.

Ionactis linariifolia (formerly Aster linariifolius; flax-leaved aster; Asteraceae)
I’ve seen this species blooming in a rocky meadow in the Carderock area in October of the last few years, but also in open, rocky areas of the Billy Goat A trail – in June!

 

Iris species, either I. versicolor or I. virginica (northern blue flag or southern blue flag; Iridaceae)
These flowers drove me nuts in 2017. I posted many times about my quest to determine exactly which species it is. There are scattered stands along and near the C&O Canal from the Marsden Tract upstream to Widewater; look for it in late May or early June.

Lobelia siphilitica (great blue lobelia; Campanulaceae) stands dramatically tall on riverbanks. I’ve seen two stands of them along the Potomac: one just upriver of the American Legion bridge, the other near Fletcher’s Boathouse in DC.

 

Mertensia virginica (Virginia bluebells; Boraginaceae)
This spring ephemeral often grows in large swaths in floodplains, like in the lead-in photo above. The pink buds start turning blue as they open. This species can also flower in pure white, pure pink, and pale violet; I love hunting for these variations every April.

Phacelia covillei (Coville’s phacelia, buttercup scorpionweed; Boraginaceae)
A short annual plant with tiny flowers that have to be seen up close to be appreciated. Currently listed S2/Endangered by the Maryland DNR, with a proposed change of status to Threatened.

Phacelia dubia (small-flowered phacelia or scorpionweed; Boraginaceae)
A fellow botanerd directed me to a large stand of this species last spring. Most of those flowers appeared white, but up close a few had this pale blue cast.

 

Phacelia purshii (fringed phacelia, Miami mist; Boraginaceae)
Listed S3 in Maryland. I’ve found only three stands of it between the Potomac and the Billy Goat B and C trails.

 

Scutellaria elliptica (hairy skullcap; Lamiaceae)
Look for sparse stands of these from Carderock to the Marsden Tract, in rocky soils where the woods aren’t too dense.

 

 

Tradescantia virginiana (Virginia spiderwort; Commelinaceae)
In some lighting situations this flower looks more purple than blue, but oh well. I’ll cover purple flowers in a future post. The plant has iris-like foliage: broad blades with parallel veins. The three-petaled flowers are another clue that this plant is a monocot. Which gives me an idea for another future post.

Drawing the Line

With permission granted to collect just a few more samples, I went back to the iris sites and got two capsules. Each one appeared to be ripe. Took them home, opened them up, photographed them…

And damn if I still haven’t reached a conclusion.

According to the Flora of North America, Iris virginica has

Seeds in 2 rows per locule, pale brown, usually D-shaped, 5–8 mm, pitted, corky. 2n = 70, 72.

while Iris versicolor has

Seeds dark brown, D-shaped, 5–8 mm, shiny, thin, hard, regularly pebbled, not corky. 2n = 108.

How would you describe these seeds?

Once again I sought expert advice, this time from the Species Iris Group of North America and an iris-specific internet forum. One kind gentleman wrote to me:

Elizabeth Miller, please see the paper attached below. Iris virginica is 2N = 70 Iris versicolor is 2N = 108, it is an allopolyploid stable hybrid of Iris virginica and Iris setosa (2N = 38) which occurred post glaciation after the Laurentide Ice Sheet shifted a population (dramatically) from Western North America all the way across to the East, into the range of Iris virginica. Since you have a permit for collection, you may wish to contact your nearest university with a Hort program and see if they can do an analysis. In general from a phenotypic perspective Iris versicolor has short standards, which it inherits from Iris setosa, which has bristle like almost invisible standards. But Iris virginica phenotypes are variable and some occasionally have a shorter or rounder standard. So it is best, and most accurate, to go with a chromosome analysis:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2735315/

[Parental Origin and Genome Evolution in the Allopolyploid Iris versicolor]

I was also pointed to the classic article “The Problem of Species in the Northern Blue Flags, Iris versicolor L. and Iris virginica L.”, by Edgar Anderson, originally published in Annals of the Missouri Botanical Garden [Vol. 15, #3, Sept. 1928].

The article was fascinating, and I’ve been struggling to come up with a way to briefly summarize it while doing justice to the detail. If you’re interested in such things, it’s worth getting a (free) jstor account.

After introductory remarks and descriptions of the species, the author presents a chart of “Comparative Morphology”, followed by some interesting observations:

Wherever either species was studied, the individual plants which went to make up a colony were found to vary strikingly among themselves. They varied in every conceivable characteristic, both vegetative and floral… The flowers varied in size and form, in color and color pattern, in number and arrangement, in texture…

…It is thus apparent at the outset that no biometric method of distinguishing the two species can be a simple matter.

That made me feel better about my own failed attempts. It also made me wonder if I wasn’t right in thinking that the lumpers should have won this round. But earlier in the paper, Anderson writes

It has been found that what commonly passes for Iris versicolor L. is made up of two species… the species are wholly distinct and crosses between them are partially sterile.

So I kept reading, only to discover that after detailed analysis of numerous specimens, Anderson discards mathematical models and comes up with a fascinating method of comparing specimens by creating ideographs based on groups of characteristics. After comparing ideographs, Anderson concludes

In marked contrast to the variation between individuals is the general resemblance between colonies of the same species.

And

Above all, when the ideographs are considered as a whole, the two species remain completely and absolutely distinct. In spite of a wide range of variation in separate characteristics, when the combination as a whole is studied it is found to be strikingly constant. Iris versicolor remains always and unmistakably Iris versicolor, and Iris virginica remains always and unmistakably Iris virginica. There is not the slightest tendency to one species to merge into the other.

So where does all this leave me? I can’t create the ideographs without access to a large number of specimens – quite possibly more than either stand of irises affords. Which leaves chromosome analysis.

And that’s where I draw the line. Even though a botanist friend has promised use of her microscope so I can do it the “old-school way”, should I be able to collect samples of root tissue.

Those Damned Irises

On June 29, with my collecting permit about to expire, I went one more time to visit those two stands of irises near the Marsden Tract*, and collected two more seed capsules. Took ’em home, opened ’em up, photographed, measured, examined with hand lens, etc.

And got nowhere. The seeds just weren’t ripe enough.

My gut feeling is that stand 1 is Iris virginica and stand 2 is Iris versicolor, based on the observed characteristics. The former is on the state DNR watchlist (S3), and there are records of it in Montgomery County, so this is not too far-fetched.

But I like proof, and I haven’t proven anything, except that I’m a little nuts, so I am going to conclude that both stands are probably Iris versicolor, because it’s the more common species.

However… this ain’t over yet.

*see posts from mid May into June