Vitaceae Seedlings; A Mystery No More

Sampling plants in quadrats is a challenging endeavor. It requires a taste for botany in its most raw and primitive state. Plants encountered in quadrats are almost always sterile and range from newborn seedlings to the withered remains of plants that may have senesced earlier in the year; and everything green in between. The field botanist spends countless hours in a growing season on his knees, head buried in vegetation, straining to use a hand lens at ground level in order to examine such subtleties as the red calluses on the teeth of Ceanothus americanus seedlings or the length of the ligule that separates Andropogon virginicus from Andropogon scoparius (Schizachyrium lacks taxonomic credibility when applied to Little Bluestem).
All this with the discomfort and sometimes fear that ticks, chiggers, horseflies, deerflies, yellow jackets, mosquitoes, gnats, spiders, snakes, falling limbs, storms, poison-ivy, heat and meth-heads illicit all around you. You know you have reached the pinnacle of a seasoned field botanist when you choose to examine a deftly teased Scleria achene between your fingers before you tend to the thousands of seed ticks that have just colonized your hand, or to wipe the searing sweat from your burning eye sockets.

In spite of this, the forests, woodlands, glades and prairies are our laboratories, where we test and untangle the differences in taxa by their simplest organs; their leaves and stems. Hard won are the tricks of our trade and they evoke an excitement that can be shared with few and appreciated by even fewer. After 12 years in the field, I am still a student of the flora and each day I am humbled by the myriad challenges of the trade.

I write this as a prerequisite for the information below in the hope that it will put the breadth of these findings into perspective. For each season a few new mysteries are solved; the knowledge that the Vaccinium can be distinguished by their venation patterns, that Impatiens can be discerned by the number of teeth on the leaf margins, that species in the genus Aristida actually have solid vegetative characters. This is the gold you can never mine from “the literature”. Sadly, it has no outlet.

One of the great unsolved mysteries in vegetative sampling has always been how to distinguish the cotyledons of Parthenocissus quinquefolia (Virginia Creeper) from Vitis aestivalis (Summer Grape). Both are members of Vitaceae (the grape family), both are commonly encountered and both germinate and persist throughout the summer. In the past, when these little groaners were encountered, they were entered onto the datasheet as “Vitaceae”; a moniker that lacks ecological significance and provides no information other than simple occurrence. This has all changed.

Earlier this summer I was innocently sampling a plot when what should appear within the boundaries of my quadrat but a bushel of Vitaceae seedlings. The first one I glanced at had three leaflets on the first true leaf emerging from between the cotyledons thus instantly giving it away as Parthenocissus. The next had one distinct leaf of a Vitis aestivalis. As I surveyed the quadrat and surrounding area I realized I was in an ocean of both species all with cotyledons intact and with one corresponding true leaf. Perhaps the tree above, lacking vines of either species, had been a turkey roost or an opossum hangout. Regardless, the area was strewn with an incredible density of both species in seedling form. I told myself that this was an opportunity not to be missed.

After a half hour of examining everything from stem thickness to overall color, I could find nothing consistent to differentiate these two beast and I had all but decided that my little observational study was as it had been, inconclusive. Then I noticed the broadly truncate-ovate bases of the Parthenocissus cotyledons and how the cotyledons were about as long as broad and thus rather deltoid in outline.

Comparing a Vitis seedling, I found the cotyledons of Vitis to be more rounded at the base and cleanly ovate in outline (longer than broad but broadest below the middle).

Twenty or thirty seedlings later, I was consistently and accurately using these characters to distinguish the two. I collected and pressed several examples and went about my merry way. For the remainder of the summer, as I have hiked to plots or walked between quadrats all over the Ozarks, I have kept an eye out for more seedlings and have found these characters to hold with 100 percent consistency. In fact, I don’t even pause anymore. They are so distinct that now I can’t imagine how this difference has gone undetected for so long.

Though this may seem insignificant in the grand scheme of nature and its study and though these findings will never grace the pages of Science, I smile every time I think of the simple hidden beauty that eluded field botanists for so long. Discoveries like this fuel my hope that some day field characters for such notorious complexes as Zizia aurea/Thaspium trifoliatum and Liatris aspera/scariosa/squarrulosa will seem as obvious as the vegetative differences between Impatiens capensis and I. pallida. The more we learn, the cleaner the data we collect. The cleaner the data, the better the management decisions based on these data will be. To me, this is science at its best; ever learning, ever revising and always hashing out the details regardless of the annoying gnat in your eye, the itch of poison ivy or the hundreds of chiggers slowly digesting the flesh from around your ankles. Afterall, science is stone.

Lactuca....hirsuta?

Lactuca hirsuta is one of the most under detected species of vascular plants in the Midwest. There I said it. It is completely off the radar for most folks, yet I see it with considerable frequency, at least here in the Ozarks. The USDA Plants website shows that it occurs in most every state northeast of Texas (north to MN and east to Maine and GA) yet it is listed from shockingly few counties in these states. I don’t know how this creature has escaped detection. Perhaps its anomalous distribution stems for the common precept that Lactuca canadensis can be distinguished from other Lactuca by the salmon/orange sap color. While this it true, one must then distinguish Lactuca hirsuta which also possesses this quality. This is easily done since L. hirsuta, as the name implies, is hirsute and L. canadensis is glabrous (disclaimer: some specimens of L. canadensis can be very slightly pubescent and some L. hirsuta can be sparsely pubescent but the vast majority are clear-cut).

Here is quick shot of the stem and leaves of L. hirsuta (above). And for comparison, here is a shot of the stem and leaves of L. canadensis (below). Also notice the difference in overall leaf shape between the two species.

There are other subtle but taxonomically satisfying characters. Most notably, the leaves of L. hirsuta are progressively shorter toward the top of the stem while those of L. canadensis remain roughly the same length from tip to toe. Also, the involucres of L. hirsuta are range from 15-22mm long where those of L. canadensis are typically 10-14mm long.

Lactuca hirsuta (above)
Lactuca canadensis (below); my thumb nail is 15mm long, for scale.

Esteemed Missouri botanist Alan Brant pointed out to me that the inflorescence (branches and involucres) of L. hirsuta are often infused with a dark purple coloration while those of L. canadensis are mostly green with some hits of purple here and there. That can clearly be seen in the involucre photos above.

So, as Lactuca are bolting and blooming across eastern North American, in your travels, keep an eye out for the lonely but hairy L. hirsuta. While I don’t have a great grasp on its habitat requirements (perhaps a bit more conservative than L. canadensis), it seems to prefer dry acidic soils with just a touch of disturbance suffused with a sparkle of full sun. Rocky soils with sparse vegetation that have recently witness fire are ideal. I remember seeing it at Indiana Dunes National Lakeshore. I can imagine that open sand would suit it just fine. Another place to find it would be the neglected stacks of almost any herbarium in eastern North America, where it has undoubtedly been misidentified as L. canadensis. Hey, let’s print off some annotation labels and head to the herbarium!

A Sabatia Induced Rant

In Richard Manning’s book “Grassland”, he wrote the following:

I once heard a story of a man who had perfect recall, so he could never carry on a conversation. He had to live in isolation because the merest stimulus, the merest sentence from outside his own head would recall everything. All the information in his head would come tumbling forth in a great rush, and he would be crushed by the pain of seeing.
I imagine that must be what it is like sometimes to be a botanist. I have been afield with many of them, and they are different, almost invariably quiet, distant. Undeniably, they see something different from what I see, as if the knowledge of the plants lifts a veil. The whole of it is there in the plants to be read, the full soul of a place, its life and the abuses of its life, the creation’s intentions and the manifest violation of those intentions. Botanists are our shamans.

While this is clearly a romantic notion, there is some truth to it. Most botanists I know often reminisce about the days before they understood the harsh realities expressed in the flora of a place. When our non-botanists parents or friends remark at how beautiful the honeysuckles smell in the summer, we grit our teeth and try to explain to their rapidly glazing eyes why honeysuckle is bad (of course they usually miss the point and come away with the thought that they should be ashamed of enjoying the fragrance). In quiet hours I often mourn the loss of such innocence. But knowledge is a heavy burden, and I derive far greater pleasure in knowing. To me, it is knowledge that is bliss. I mention this because I believe this is one of the fundamental social functions of the botanist; to shoulder the burden of the knowledge of place and attempt to interpret the landscape for those off chasing money or fame or any other thing that an honest botanist will never know.

On this note, this year more than any other, I’ve noticed rather interesting changes in the flora. Aberrations like Platanthera lacera have come up by the thousands across the Midwest. Platanthera leucophea has had a boom year in existing populations and new populations have been found. Listera australis, a more eastern and southern species, has been discovered in Missouri and Platanus occidentalis and Morus rubra seedlings are sprouting on the bone dry ridge tops of the Chilton Creek Preserve. Just to name a few examples. On my own 16 acres I regularly take walks and I have noticed a dramatic decrease in the populations of xeric species like Krigia dandelion, Helianthus mollis, Helianthus occidentalis, Spiranthes vernalis, Gymnopogon ambiguus and Polygala incarnata while witnessing an increase in mesic species like Dichanthelium laxiflorum, Salix humilis, Pedicularis canadensis and Senecio aureus. However the most dramatic change, in terms of population and sheer flora display, has been Sabatia angularis (photos distributed throughout this entry).

In a typical Ozark summer, S. angularis blooms in scattered populations across prairies and old fields; a plant here, a plant there. This year, however, the populations are large and dense and the plants are huge! The field in front of my house, in which Sabatia typically goes relatively undetected is literally pink with plants. While driving across the Ozarks one cannot help but notice their abundance. A naturalist friend of ours just sent us a letter documenting the phenomenon throughout Texas County as well. I speculatively attribute this phenomenon to the past two wet years that have followed several very dry years (at least in the Ozarks). I’m sure there is more to the story than this simple answer. And I’m sure this is all within the ebb and flow of the natural order of things where variations in seasonal severity lend boom and bust years to a resilient biota. But I fear there is very little documentation of such phenomena and any trends that may arise. Sure, a handful of rare species are occasionally tracked given funding and time, but who is watching the big floristic picture? There are various projects monitoring the phenology of plants in an attempt to document the effects of climate change, but what about the changes in structure and composition of natural communities in general that may be outside the narrow scope of climate change. Regardless of cause, what if the Ozarks are getting wetter, for example? This would have tremendous effects on glade and woodland restoration/conservation efforts to say the least.

This brings me back to the main point. In the heyday of ecology, botanist/ecologist like Lucy Braun, Henry Cowles and Julian Steyermark spent countless hours documenting the flora through descriptive floristics projects. This included such elements as a list of species, their abundance and frequency and the overall structure of the vegetation of the site. All this from quadrat and transect data. Now such techniques are largely considered to be only of historical significance by academics and are rarely undertaken and almost never funded outside of an occasional study conducted by a graduate student. When I mention this void in the sciences to professionals their reactions are rather dismissive, as though I am evoking some sort of nostalgia-based concept of scientific responsibility rather than anything of ecological or social importance. Perhaps if the topic were polar bears, they would lend a sympathetic ear. It is increasingly obvious that respectable botanists that can identify plants without flowers and the aid of keys, dying breed that we may be, are being underutilized and certainly underappreciated. Sure, our skills are often called upon to put together an occasional species lists or partake in a bioblitz, but these activities lack any ecological significance outside the stark documentation of occurrences. They provide no information about abundance, structure or conservation. Somehow a species list has become an acceptable replacement for actual data.

In a society that continues to destroy natural communities and impact natural processes at an ever accelerating pace, now is not the time to stop describing the remnants. From the ever shrinking crumbs of our natural system, we may yet be able reconstruct or at least envision the cake. To most, crumbs aren’t exciting. After all, far reaches of the tropics still have big pieces of cake upon which to feast the intellect. Sadly, most academic botanists lack the ability to even identify the most common species in the remnant woodlots behind their expensive suburban homes. Meanwhile the only plants most botanists under the employ of state and federal governments get their hands on are the various trees used in the manufacture of their pencils. In effect, environmental consultants are conducting the lion’s share of descriptive ecology, though often by poorly trained staff and for reasons not conducive to ecology or science. So while the botanical “shamans” mentioned by Manning may be a bit of a misnomer, where are they? And who is going to tell us how the natural system is responding to changes, natural and human induced? How will we detect localized extinctions inherent to a fragemented landscape? Gerould Wilhelm once said, “You cannot take care of what you cannot see”. So where are the seers and why aren’t they seeing?