In June 1990, the International Association of Pteridologists met in conference at the University of Michigan in Ann Arbor. During the week before this meeting, 27 of us who came for that conference visited Northern Michigan and the Upper Peninsula, and found many rare ferns and fern allies. The leaders of this expedition were Jim Montgomery, Joe Beitel, and Florence and Herb Wagner, who knew all the best spots and took us all there.
In addition to the four leaders, the group consisted of 14 professional pteridologists, 2 graduate students, 6 serious amateurs, and one pretty pterrific spouse. Many of the professionals were world-class experts in various genera. People came from as far away as Mexico, Scotland, Japan, Poland, Hawaii, Belgium, and New Zealand.
We were promised a lot of ferns, and ended up seeing 81 species and hybrids. The emphasis was on Dryopteris hybrids, Botrychium, and the fern allies.
On Sunday, June 17, we met for last-minute instructions and received a very complete, excellent description of the foray from Jim Montgomery. We set out bright and early the next day, and returned to Ann Arbor tired, happy and satisfied on Friday, June 22. We were put up at the University of Michigan Biological Station on the shores of Douglas Lake, in Northern Michigan, where the accommodations were comfortable and the food wholesome. During the days we went from spot to spot in a bus, making as many as six stops per day. Each of the stops was described and shown on a detailed map, so we always knew what to look for in advance. Even on the first day, we had a stop in the Upper Peninsula after driving from Ann Arbor.
We discovered new locations for a few ferns, and most of us got our first look at several newly described Botrychium species. On the first day we encountered Polystichum lonchitis, the green spleenwort Asplenium viride, and the walking fern A. rhizophyllum. Ronnie Viane from Belgium spotted Cystopteris laurentiana in a new location, but not the first in the state. This rare fern, which arose from an ancient cross between C. bulbifera and C. fragilis, can be recognized in part by its abortive mini-bulblets. We found only one of its parents nearby; what looked like C. fragilis was actually C. tenuis.
We spent Tuesday in the Upper Peninsula. First we visited the Hiawatha National Forest and saw many species of Botrychium. Most of these are tiny little things, easily overlooked. The two Wagners had only recently described B. campestre, B. hesperium, B. spathulatum, and B. acuminatum, all of which we saw before the week was out. In addition, we were introduced to an unannounced taxon, probably a species, tentatively to be named after Hiawatha National Forest. These are all similar to the moonwort B. lunaria, which we also saw. In all, we found some ten Botrychium species that day, including the tiny B. pallidum in a new location, spotted by Joyce Drife. Later that day we went to a very interesting limestone pavement location where the rare male fern Dryopteris filix-mas was growing in profusion. Finally, we visited a location with Selaginella eclipes and where, much to our surprise, S. selaginoides was found by Iván Valdespino, who is working on a thesis on this genus. This unusual site also yielded one of a long series of Lycopodium species and hybrids, Huperzia x buttersii, a hybrid offspring of H. lucidula and H. selago.
I guess I have to explain what has happened to the Lycopodium group of fern allies. Your books probably list these two species as Lycopodium lucidulum and L. selago. The modern view embraced by the foray leaders is to group the northern North American Lycopodium species into four genera. First there is the surviving genus Lycopodium, containing L. obscurum and the similar species L. hickeyi and L. dendroideum, along with L. clavatum, L. lagopus, L. annotinum and some others. These have a creeping rhizome, upright branched stems, and distinct strobili where the spores are found. Next is the new genus Diphasiastrum, which also has spores in its strobili, but has more flattened branches because the small leaves are fused to the stem. The species include D. tristachyum and the similar species D. complanatum and D. digitatum (formerly flabelliforme), D. x sabinifolium, and others. The third genus is Huperzia, whose species bear their spore cases in axils of normal leaves. The three Huperzia taxa listed in the previous paragraph are the only ones we encountered on this foray. Finally there is the "whatever is left over" genus Lycopodiella, of which we found only L. inundata.
On Wednesday we stayed in the Lower Peninsula and seemed to specialize in Equisetum and Dryopteris. But first we visited a swamp where Gymnocarpium robertianum and the more common oak fern G. dryopteris grew. This was an unusual site for G. robertianum, which usually likes limestone cliffs. But then perhaps this is par for the course in Northern Michigan, since on a nearby island there is a famous location where Polypodium virginianum grows on a log, rather than a rock. Some ferns simply don't know where they're supposed to live.
After visiting a magnificent stand of Diphasiastrum tristachyum, we went to a rich damp slope with Adiantum pedatum, Dryopteris goldiana, Equisetum hyemale, and other species. Then we ate lunch and had our picture taken among Botrychium lanceolatum, B. matricariifolium, and various other species. Finally we visited a swamp with lots of Dryopteris hybrids, including D. x uliginosa, D. x triploidea, D. x boottii, D. x slossonae, and D. intermedia x marginalis.
Thursday found us back in the Upper Peninsula, on the Grand Sable sand dunes along Lake Superior. We had a fine time hunting Botrychium , finding a total of ten species. While most of us were eating lunch, Carl Taylor, an expert on the quillworts, waded out into Grand Sable Lake and brought back Isoëtes lacustris and I. echinospora. It was the first time some of us had ever seen these plants and examined the megaspores. Carl claims he can distinguish the Isoëtes species by feeling them with his toes. At this site Tom Morgan found Polystichum braunii. On the return trip, we stopped at a borrow pit. This term is used for what is left after the Highway Department takes some of the soil for road construction. A borrow pit is an example of a disturbed location, and it seemed that many of the sites we visited had unusual ferns or fern allies growing on them precisely because the disturbed locations offered unusual habitats. This particular borrow pit was nothing short of Lycopodium Heaven; we found 12 hybrids and species from all four genera.
[Note added March, 1999: Readers are reminded that disturbing or removing plants is not allowed within national or state parks without a collecting permit. Grand Sable Dunes and Grand Sable Lake fall within a National Park, Pictured Rocks National Lakeshore.]
On Friday our disappointment at having the trip almost over was not even tempered by the discovery of Equisetum x ferrissii growing by the roadside near our dormitory. After a stop to see Selaginella rupestris we had an uneventful return to Ann Arbor, in time for the IAP conference, which started the next day. It rained every day we were out, but with these 81 ferns to see, nobody seemed to mind.
Species and hybrids seen (81 total):