Thursday, December 06, 2012

Wild and Crazy Foxglove


At first it seemed like a restoration attempt that failed. Then, for a while, this partly parasitic beauty just barely hung on. Gradually, we learned to nurture a species that could be called "wild and crazy."

The eared false foxglove (Tomanthera auriculata) is threatened in Illinois and under review by the U.S. Fish and Wildlife Service for the federal endangered list.

Eared false foxglove – first confirmed near the North Branch by a student of H.S.Pepoon, 
who probably traveled to its habitat on the “Crazy Train.” 
According to the “National Collection Plant Profile” of the Center for Plant Conservation, this species has “About 40-50 known occurrences, most with populations of only 25-250 individuals.” The largest populations are found in Arkansas, Mississippi, and Missouri. Recently discovered in Kentucky. Presumed extirpated in Michigan, New Jersey and Texas.

The species was already rare here in 1927 when H.S.Pepoon published the Flora of the Chicago Region. But one of the three occurrences he listed was a few miles south of Somme at “Dunning” – then a relatively wild and unsettled area. Most people didn’t want to live there, because that was the location of Chicago’s insane asylum. The main transportation to Dunning was called the “Crazy Train.” This false foxglove may actually be a bit unbalanced itself; the species seems not to do well in settled situations; the little rascal seems to need violent disturbance.

Methods

We noticed this foxglove in small numbers at three sites in Cook County; at each it seemed to be associated with areas where shrubs had recently been burned back by fire. Fluctuating shrub borders were once a major feature of the tallgrass landscape. Shade from shrubs can kill prairies. When we started with Tomanthera, most prairie managers were trying to wipe out shrubs completely.

We wondered if this species might have a role in the savanna dynamic (Packard 1988). We collected a few seed capsules from a few plants south of Dunning. We broadcast that seed in areas of Somme Prairie Grove that seemed similar to where we found it and had similar plant associates to those listed by Swink and Wilhelm (1994). A few years later we heard from Ron Panzer that a large population near Midlothian was about to be destroyed. Panzer provided us with about one quart of seed capsules, and we broadcast that seed where a few of the Dunning plants had first bloomed.

Date of the First Seeding

Oh, yes, it would be great for this report if I could find records of those first plantings. I can’t, so far. I do remember that they happened.


Tomanthera’s seeds are odd and fragile looking, yet they survive in the soil 
and germinate after many years. What’s with the honeycomb effect?

A 1988 reference in Natural Areas Notes suggests that I may have sowed the seeds that early. I was collaborating then with Gary Horn, a fellow volunteer steward and an animal keeper at Brookfield Zoo. He carefully managed the “south of Dunning” site. We had just started to burn that newly discovered prairie, and the foxgloves popped up next to some burned shrubs. Gary has sharp eyes, and he discovered that deer were eating all the foxgloves before they could set seed. So he tried some recommended deterrents: he scattered human hair near the plants (a failure) and then lion hair (also failed). He finally succeeded with his ‘ultimate weapon’ – leopard dung. According to Gary, “Leopard dung has a smell beyond imagining.” He reported that his rare plants then flowered and set seed.

The first foxglove entry I can find in the Somme field journal comes ten years later:

“Sept. 4 (1998). Tomanthera auriculata appeared for the first time (although I can easily believe it’s been there previously; it would have been easy not to find it; especially since the flowers fall off by afternoon).”

For five years, no subsequent mention of Tomanthera in my journal – but in 2003 there’s the note:

“August 24. Found Tomanthera auriculata for the first time in years. Also first time in years that that area has burned. 31 plants along old footpath to Circle Grove … scattered up to 10’ from the trail. Also found one plant 2/3 of the way to the Pothole Pond ... Both of these (areas) have now been scythed.”

Here's the translation: An intense fire – scorching a brushy area that hadn’t usually burned – results in thirty-one foxglove plants. And why scything? A scythe is that long-bladed implement that Father Time carries on New Year’s. We had noticed that saw-tooth sunflower and tall goldenrod could be “thugs” – nasty and destructive competitors. In high quality ecosystems, they’re not common but multiply after disturbances, like a scab that helps heal a wound. In degraded ecosystems, like we’re working to restore, they can get out of hand and prevent healing. In previous experiments, scything these thugs back into balance seemed to have long-term benefits for diversity generally – and especially for some rare plants. Now we started to help out Tomanthera by scything thugs in areas where it used to thrive. We later found that the foxglove sometimes returned years after scything. One good thing about crazy annuals is that seed may lie in the ground for years or decades, waiting for the right conditions.  

In July 2004 eighteen Tomantheras bloomed. So far so good. But a note in my journal that fall indicates that only one plant survived to make seed. That hurts. I remember a foreboding: What’s wrong here? Is Tomanthera doomed – a few plants pop up some years; then they’re gone, perhaps no new seed being made for the future. 

Almost certainly I took half the seed from the one successful plant and scattered it in other likely places. I find no note to that effect, but that's what I would have done with so rare a plant.

In 2005, the data page shows a whopping 75 plants bloomed. Did they survive to make seed? Did I check? No note on that. Certainly I had good intentions - but lots of competing work and only so much time. My comments in 2006 suggest disaster  and a determination to do better.

August 27, 2006: a jumble of rushed words:

“Put out 2 cages and 8 mouse traps for Central Swale population of Tomanthera. (There had been 6 plants on the 25th. One of them cut off at ground level on the 26th.) 28th: 1 short-tailed shrew. 29th: 1 each deer mouse and meadow vole.”

There my notes stop, but my memory is vivid. Mouse traps? Short-tailed shrew? The battle has just kicked up a notch.

Here's the drama, as it unfolded: On August 25th I had been excited to find six foxglove plants far from the area where I’d seen them in the past. (Probably I’d broadcast seed in all these areas back when Panzer donated it. Probably the little crazy little devils sense chemical and physical changes that indicate conditions may be right for them. Then they germinate and bloom. If they can set seed, the population may continue. If not, the population flickers out.) When I checked the next day, one of the six had been cut and sectioned. Not only were the deer eating the foxgloves from above; the meadow voles were attacking from below.

Voles are clever. They stay in grass tunnels but drag lofty seedheads down to them. A vole stands up and gnaws through the stem, grabs the new bottom, pulls it down to the ground, stands up, makes another cut, and keeps repeating that sequence until it has a pile of vole-length stems on the ground and the seed capsules down where it can eat them in safety. Hawks eat voles that are not hidden in the tunnels they make through the grass.

So on the 27th I probably pirated a couple of deer protection cages from some lesser priority species and put out 8 humane Havahart live traps baited with oats, peanut butter and molasses.

Next day, despite my efforts, another stem was vole-cut. Four left. If we could only protect just a few long enough for next year’s seed. I had a dozen snap traps to fight off the mice that otherwise devastated the rare seed we gathered and stored for later planting. But killing the little gerbil-ish rodents in the wild (even with FPD approval) felt different and more ugly. All the same, losing an endangered species population felt worse. However, no voles blundered into the snap traps despite delicious bait. One shrew was in one trap. Next day, another foxglove was gone.

On the 29th, one vole and one mouse died in traps. But others had avoided Havahart and snap traps to get another Tomanthera. The assortment of contraptions looked insane amidst the nature.

Next day, another foxglove down. Now just two left. I have other things to do in life. I don’t have time for this. But I go to the hardware store and get talked into a package of stinky stuff – blue cakes of foul stench – guaranteed to repel voles. I place four of them around those two vulnerable stems.

Next morning I return, wracked by angst. Yet the scene I see makes me laugh out loud. It’s an oddly free and happy laugh – a laugh of the absurd. I stare down at a little piece of wilderness decorated by 2 big green deer cages, 8 silver Havahart traps, 12 tan and gold snap traps, 4 bright blue stench cakes, and the last two foxglove stems sectioned and lying carnage among the pathetic technology. Every last ripening seed has gone to its doom.

I began to experiment with vole exclusion cages. They are harder to make and harder to install – a cylinder of half-inch metal mesh. I’m hoping they don’t need tops, because voles stay low. One more “to do” during a busy time of year – yet they work. 

Note from 2007: tried spraying repellent on the foxgloves.

2008:, all but three plants were destroyed by voles. Those three plants wore the newly invented vole cages.

An Angel from Darwin or God

Then a human miracle happened. A year earlier, mild-mannered occasional volunteer Lisa Culp asked if there was more she might do. I hardly knew her. She said later that I “baited” her with fringed gentians. Not really. But I did tell her that deer and voles had been eating nearly all of those rare beauties, and would she like to adopt them? Lisa, who sometimes compares herself to “the Energizer Bunny,” made deer and vole cages for every gentian, scores of them, a lot of work.

Lisa was celebrating a year of gentian success and happily preparing for the 2009 gentian season when I laid before her the plight of the foxgloves. She gave it some thought. Then the mass production of vole cages began. In 2009, all large plants were protected. Probably as a result, in 2010 Lisa had the great pleasure of being witness to a huge surge of foxgloves 178 plants – too many to cage – even for Lisa. Still, she caged scores of them.

Is this too much meddling with nature? I sympathize with whoever answers yes. To land managers and stewards who don’t want to do it, I say, “Great. Your site tests the No Heroic Action alternative.” Yet the effort seemed good to us. Can it be judged by the results?

2011 – now numbers have blown through the roof. 719 plants. Still caging as many as we can.

The graph below shows this population limping along in very low numbers for many years. Then it seems to explode. By 2012, we’re thinking that we may be “over the hump,” and perhaps so. But after you pause for a happy look at the graph, see concerns below.


In one big way, 2012 is a failure!  This year we rest on our laurels. We cage just a few. We concentrate our energies on other species. Voles eat most Tomantheras without a vole cage – many hundreds. We also lose about half the caged ones, probably to white-footed mice. (Voles stay on the ground, but the rascally white-foots are great climbers.) Maybe some foxgloves make so much seed that losing 95% of the plants is good enough? Many species on the planet lose most individuals – to something or other – and still prosper. Is it even possible that critters actually help distribute seed in some way?

Our decades-long study was gloriously imperfect. It had to outlast changes in jobs, places of residence, life goals, etc. This account suffers from some lost data. But it sure beats doing nothing – or those neat and complete little studies of a year or two. Let me revise that: it offers something that shorter and “more scientific” studies don’t.

Next steps for the foxglove at Somme? We’ll continue to ask advice from the best experts we can find. We’ll probably broadcast the much-increased amounts of seed in various areas and record as best we can what seems to be happening under various management regimes. At some point, probably, we may just tell Tomanthera to sink or swim without our help. It will find niches, or not, and persist, or not. Best of luck, Tomanthera auriculata.

Credits

Principal credit for the success of Somme’s eared false foxglove in recent years goes to Lisa Culp who does most of the caging. She reports that she makes 16 vole cages per hour.
Great credit also goes to Forest Preserve District of Cook County fire manager John McCabe who has vastly improved the controlled burn program in recent years.

Thanks to Karen Glennemeier, Ron Panzer, Gary Horn, John Balaban, Bernie Buchholz, Linda Masters, Steve Flexman, Robbie Sliwinski, Doug Chien, Lisa Culp and many others for edits and for their contributions over the years.

Photos by Lisa Culp

References:

Center for Plant Conservation: www.centerforplantconservation.org/Collection/CPC_ViewProfile.asp?CPCNum=6601
(Note that scientific names change, and Tomanthera is also called Agalinis.)

Cunningham, Maureen and Patricia D Parr, Successful Culture of the Rare Annual Hemiparasite Tomanthera aurucularta (Michx.) Raf. Scrophulariaceae), Castanea 55(4) 266-271. DECEMBER 1990

Packard, Stephen, 1988, Rediscovering the Tallgrass Savanna of Illinois:
digicoll.library.wisc.edu/cgi-bin/EcoNatRes/EcoNatRes-idx?type=div&did=EcoNatRes.NAPC10.PackardSavanna&isize=M

Swink and Wilhelm, Plants of the Chicago Region, 1994.

END NOTES

1. If anyone who lives nearby would like to help on this (or some other) rare species, let us know through “Comments” here or “Contact us” at www.sommepreserve.org. There are lots of great experiments to try for anyone who finds this work compelling.

2. Some people think we should not reveal the locations of rare plants. They may be right. There’s danger of misbehavior if rare species locations are not kept within a limited community. Botanical psychopaths may steal plants or seeds from known populations. They may degrade, damage or destroy other populations or ecosystems as they indulge in “copycat” vigilante efforts of their own design. But secrecy can also kill. We need to build constituency and enthusiasm for endangered species work; we need our ideas enriched by broad discussion. Overall the best results may come from empowering more conservation than can possibly be done by the grant-driven scientists and plodding bureaucracies that, bless their hearts, do most now. This argument suggests the need for “wiki” type safeguards, ethics, and communication. Your thoughts? 

11 comments:

Kathleen Garness said...

The honeycomb pattern on the seeds reminds me of morels. Is it to help absorb moisture from the soil, increase the amount of surface area to absorb nutrients and water? - Just curious. K

Stephen Packard said...

Oh, Kathleen, I love your question. I wish I knew the answer. Perhaps someone will have suggestions. In a prairie soil with highly developed crumb structure, this honeycomb surface could actually keep the seed separated from moisture etc. The plant is said to be partly parasitic. More surface for some parasite reason??? Also, many plants that, like this foxglove, are in the figwort family have weird seeds. It would be interesting to look into what that's about as well.

Anonymous said...

When I saw these seeds, I immediately thought the honey comb structure was a fire adaption. The insulating honeycomb should effectively protect the delicate embryo from extreme but quick heat.

In contrast to this rare grassland annual, most other prairie or savannah plants are long lived perennials. If long lived perennials have all their seeds killed by a fire, they have time to wait for a favorable season. Annuals do not have the luxury of trying again next year. This is likely the reason the seeds of Tomanthera and other Scrophulariaceae have evolved an insulating exterior structure. Having one of the few seeds that can survive a fire would be a significant advantage to a seedling following a burn. It is also likely that the honeycomb structure helps prevent germination until after a fire by excluding moisture (as Stephen mentions above).

My college Thermodynamics instructor would have been so proud of me for finding a novel application of the subject.

James

Stephen Packard said...

Interesting comments, James. A quick Google search produced quite a few research articles on the seed germination of Tomanthera (and other fire=adapted species). Many complex issues arise from those papers. It might be fun to research some this more (although I didn't notice any immediate implications for conservation decisions).

Anonymous said...

One implication for conservation decisions from germination studies is that the seed of certain plants, like many grasses, germinate strongest with the most robust seedlings when collected the season after a fire. In contrast, a number of forbs have lower germination and weaker seedlings from seed collected the season after a burn has occurred. The time of seed collectors is best spent collecting certain species from areas that have recently burned and other species from areas which have not burned recently. This does not relate to the Tomanthera specifically, but restoration efforts more generally.

What I have noticed was lacking in the literature was studies on seedling recruitment in the wild after the occurrence of a burn. This information would be useful to those who broad cast seed for restoration. Different species would be sown depending whether a burn was scheduled to occur sooner or later. Fire can have a significant effect on germination. It is well known that certain species like Ceanothus and Baptisia germinate better after heat treatment.

Considering the Tomanthera is hemi-parasitic and seems to like disturbance, I suggest conducting an easy experiment. I would sow seed on the surface of two areas where people and deer have been excluded. One area would be the control and have no treatment. The other area would have the surface disturbed by raking just enough to scratch or beak surface plant roots.

The reason I suggest the above experiment is an additional engineering use of a honeycomb structure is great strength. The structure of the seed might be evolved to protect the embryo from trampling. Trampling that might be necessary for this hemi-parasite to attach to the roots of a host.

James

Stephen Packard said...

James, more good thoughts. Thanks.
The experiment you describe sounds good to me.

Anonymous said...

Of course to do the above experiment you would have to have a population of seeds that had been trampled and a population that were not trampled in each area. It would be worth recording the faces of those on the Nature Preserve Commission when you told them you planned to take very rare seed and step on it. :)

James

Paul said...

You're a much better scientist than most.

Mark said...

This is a very thought-provoking post, Steve. It demonstrates the value of accumulating data over time. At my site Tomanthera stubbornly blooms during a period when one monitor goes on an annual vacation, so plants that formerly were counted in flower are now counted in seed. The predation of plants in seed that you so vividly describe may explain the observed drop in numbers. Yet the now continual presence of a hawk and coyotes on the site may indicate an evolving predator balance that requires no further intervention to maintain the Tomanthera.

Another observation is the apparent shift in the population center toward the wetter end of the prairie. Was that a one-time response to drought conditions? Is it a permanent shift, or just a snapshot of the continual migration of annuals? More data is needed - and more Lisa Culps!

Stephen Packard said...

Mark, thanks for the interesting observations. I too have seen species move around sites, perhaps because of wetter or drier years. Or hotter or colder, or early spring vs. late spring, or whatever. Sometimes it almost seems like some species don't like to stay in one place - as if they've used up something in the soil for now - or they only thrive in one phase of the constant cycling of successional states or sets of associates that seems so compelling in prairies, savannas, wetlands and (perhaps) oak woodlands.

Anonymous said...

Here is an interesting article on others who have tried to propagate this seed:
www.jstor.org/stable/4033421

John Cherry