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|
Can anyone describe success restoring this plant effectively over a large area?
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:
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 email@example.com.