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Wednesday, June 19, 2019

Rotten Bastard Toadflax: and related quandaries

Bastard toadflax (Comandra umbellata) is one of the most important species of the highest quality tallgrass prairies, but it rarely does well in restoration.

We try various approaches. We just began harvesting this year's seed and noticed that much of it seems grotesquely deformed by mold.

Apparently rotten seed on left
Does anyone know what this apparent mold is? Does it destroy the seed? Help the seed? Not make any difference?

Master propagator Rob Sulski experimented with about a thousand seeds given to him by Bernie Buchholz from Nachusa. Only half a dozen germinated. Later Rob experimented by comparing the hard-to-get, fully ripe brownish black seed - compared with light brown, compared with yellow seed, compared to the much-easier-to-get green seed. The riper seed is hard to get because it falls off the plant soon.To his great surprise, Rob found that the ripe seed mostly failed to germinate, but the green and slightly yellow seed germinated abundantly.

There seems to be an unusually large amount of seed at Somme, this wet cold year. So we started picking when we saw seed turning yellow. Unfortunately it seemed that the yellow was mold.


I apologize for posting this disgusting image (or at least I think it's gross, unless someone has better info). The formerly spherical seeds elongate, and, when I poke at them, they seem soft.

Here's what green, non-moldy (possibly unripe seed looks like:
Rob's response to these questions was that the deformed ones are probably useless, but that the round, green ones that look like the above are probably good.

Toadflax is said to be partially parasitic, so he's experimenting by planting seeds with various "host" species. We've been planting out his mixed plugs, but few of them seem to do well, at least at first.

Some of our old plantings seem to have had a seed or two germinate and prosper. Slowly. Over the years. Now those plantings have patches with diameters from a few feet to, in the case of the largest,  about 50 feet.

Well, actually, to be more precise, it's 56' north to south and 53' east to west. For years it had been almost perfectly circular, but then it had some trouble crossing a minor footpath. Finally it crossed, and its inexorable march continues, at the rate of perhaps one foot per year. (We're studying that.) Thus, with a radius of 28 feet, perhaps we planted it 28 years ago, in 1991. But if this species (as some of our observations suggest) is a slow starter, perhaps this seed was planted in 1985 when David Painter was doing so great a job gathering and planting them.

Another thought: Do we really have to do this work? Vegetatively spreading at the rate of one foot per year, toadflax could cover the site by itself, from plants that survive in a small high-quality area near the center of the site. But to get all the way to the north edge (1,295 feet away) and the southeast corner (1,372 feet away) would take 1,295 years and 1,372 years respectively. Until then, perhaps, those un-recovered parts wouldn't be able to live up to their biodiversity conservation potential. And plant and animal species with limited habitat and population size ... could be lost.

Why do the best prairies - where all the rarest plants do best - have lots of bastard toadflax? Perhaps the simplest answer is that they all evolved together?

Please contribute info as a comment (below) or by email at sommepreserve@gmail.com.

8 comments:

  1. Stephen,

    I have no answers, only my observations. It is a very good year for bastard toadflax seed. I have found seed on every toadflax site (Wisconsin) that I know of. This amount of seed is highly unusual as most years there is none. I have not seen any mold on the seed.

    I know one person who claims they had success from seed but it took 25 years before they noticed the plant. I personally had not seen any plants yet from my seeding. I have tried several methods, including inserting the seed directly into clumps of little bluestem grass. I have not been doing it for 25 years so I am still holding on to hope.

    I have been successful moving it around my place by transplanting. And, as you observed, it spreads very slowly. One foot per year is about right.

    Toadflax clones are a great place to observe so many conservative plants. Alumroot, many species of violets, pale spiked lobelia, milkworts, small skullcap and many other hard to find little plants like to hang out in bastard toadflax clones.

    Thanks for all your posts Stephen. Please keep writing.

    David Cordray

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    1. Thanks, David, for good observations. Another curious phenomenon I've observed is that this species often fruits in the most dry and thinly vegetated parts of a site - though it grows luxuriantly in the more mesic parts. I wonder if its roots continue to connect the patch as it spreads, and it uses resources from afar to produce seed where animals would most easily get at it.

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  2. You call that seed, but others say they're drupes. Anyone want to try feeding them to their chickens or tame finches and then collecting the exposed seed for planting post consumption? Sources say toadflax spreads locally as a clone but disperses longer distances in the gut of a bird. Maybe digestion scarifies the seed to allow germination.

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    1. Thanks, Ryan. That experiment could be an interesting one. On the other hand, it's also true that our areas are full of birds that might eat it, and they do a very little spreading. But, as you suggest, if a new plant gets started far away even a very small proportion of the time, that could be of great benefit to a slow-spreading plant.

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  3. This comment has been removed by the author.

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  4. From Kirk Garanflo

    The University of Illinois Plant Clinic (https://web.extension.illinois.edu/plantclinic/) will identify plant diseases for a modest fee.

    It also provides other services. To quote: “Let us help with your plant problems. We do plant and insect identification, diagnosis of disease, insect, weed and chemical injury (chemical injury on field crops only), nematode assays, and help with nutrient related problems, as well as recommendations involving these diagnoses.”

    Kirk

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  5. From a recent GRN blog: Despite collecting thousands of seed over the past 20+ years, we have had virtually no germination in our plantings. We tried every imaginable combination of scarifying and stratifying, various planting depths and addition of soil from existing stems.

    We decided to try a genetic rescue. We’d move pollen from one population more than a mile to the receiving population and hope the resulting seeds would germinate. The biggest challenge is that Comandra flowers are a few millimeters across.

    With high precision tweezers under a microscope my wife harvested tiny pollen bearing anthers. She then delivered it to the stigma of the receiving flowers that had been previously bagged with nylon netting to prevent the regular pollinators – flies and small bees – from beating us to it. I held each stem against the wind, and she dabbed the stigmas with pollen, carefully avoiding the five surrounding anthers.

    We’ll soon collect the resulting fruits, plant them, and hope to see seedlings next Spring. In the meantime, the Chicago Botanic Gardens is looking for mycorrhizae associations among the various populations and a separate genetic analysis to determine if the Comandra is all part of a mammoth clone or distinct populations that we might cross pollinate.

    Update: Our limited experiment of twenty-five transfers yielded only a single fruit. But Emma Leavens, the researcher from Chicago Botanic Gardens, subsequently determined that some of our comandra populations are significantly different geneticallyfrom others. We will use that information next year to select the most promising matches for cross pollination when we try a larger sample.

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