Timmia megapolitana:
Lime-loving, Pretty, and Pretty Rare
Lying just west of Cedarville, owned and managed by Greene County Parks and Trails, lies the 169-acre Indian Mounds Reserve. This is a lovely wooded area with irregular terrain and numerous limestone rock outcroppings. Having a geology and plant community composition similar to nearby Clifton Gorge State Nature Preserve and John Bryan State Park, it’s a great place to see, say, blue ash, hepatica, and snow trillium, along with many bryophytes having an affinity to calcareous sites. Among them are some that are to be expected in places like this: rose moss (Rhodobryum ontariense), hook-beak tufa-moss (Hymenostylium recurvirostrum), and hemisphaeric liverwort (Reboulia hemisphaerica). Having visited this park about a dozen times over the previous decade, and pored over many of the rock ledges in search of lime-loving cryptogams, I was surprised and delighted in the spring of 2019 to see, at one spot, a robust acrocarp with a general aspect suggestive of Atrichum, but having leaves that were uniformly thin, curled upwards (involute) along the margins, and light yellowish- green. This turned out to be Timmia megapolitana, a member of the Timmiaceae, described by Guy R. Brassard in volume 27 of Flora of North America (Oxford University Press, 2007) as “a small, taxonomically isolated family” containing only 4 species, all of which occur in North America (but there’s only this one in Ohio).
The “Habitat” description by Brassard reads thusly: “Almost always with sporophytes. Most often in deciduous forests, on humus in moist, shady calcareous sites, northwards in forested localities, especially along major rivers, and as an adventive in disturbed sites such as lawns, golf courses or cemeteries.”
A peculiar feature of Timmia is that its calyptra has a median longitudinal split that causes it to be persistent on the neck of the capsule or the seta. This upwardly-pointing appendage is the basis for the name “Indian feather moss, explained by Brassard thusly: “The common name reflects the resemblance of the erect, persistent calyptra to the feather headdresses used by some North American Indians.” On iNaturalist it is called “warrior moss,” possibly for the same reason.
Speaking of iNaturalist, that much-utilized natural history observation aggregation web site lists only 34 North American observations for warrior moss; this Indian Mounds location is the only Ohio one. It seems like this is a rare moss.
Its rarity in Ohio is further spoken to by looking at the more comprehensive and bryophyte-centered Symbiota portal, Consortium of Bryophyte Herbaria (https://bryophyteportal.org/portal/), which gathers together records of specimens in Herbaria worldwide. Here we see 2535 North American records, of which 44 are from Ohio. Among the Ohio records, the only 21st-century station is mine from Indian Mounds. The most recent collections besides that are the following: one made in 1975 by Jerry Snider at John Bryan State Park, and before that, two specimens taken on the same day by Paul Redfearn at one location in Clifton Gorge in 1968. Other, earlier, locations are scattered across the state.
As set forth by the Ohio Department of Natural Resources, a native Ohio plant species may be designated endangered if, based on its known status in Ohio, one or more of the following criteria apply.
1. The species is a federal endangered (FE) species extant in Ohio .
2. The natural populations of the species in Ohio are limited to three or fewer occurrences.
3. The distribution of the natural populations of the species in Ohio is limited to a geographic area delineated by three or fewer U.S. Geological Survey 7.5 minute quadrangle maps.
4. The number of plants in all the natural populations of the species in Ohio is limited to one hundred or fewer individual, physically unconnected plants.
A native Ohio plant species may be designated threatened if, based on its known status in Ohio, one or more of the following criteria apply:
1. The species is a federally threatened (FT) species extant in Ohio but not on the state endangered species list.
2. The natural populations of the species in Ohio are limited to no less than four or more than 10 occurrences.
3. The distribution of the natural populations of the species in Ohio is limited to a geographic area delineated by no less than four or more than seven U.S. Geological Survey 7.5 minute quadrangle maps.
Might warrior moss be a suitable candidate for listing as an Ohio Rare Plant? I think so.
Of course, absence of evidence is not evidence of absence, but with the increase in interest in the Ohio bryoflora, especially that associated with OMLA forays and independent outings by our members, we would expect some sightings of this large (for a moss) and distinctive (for a moss) moss. With only three documented locations in over 50 years, coupled with the geographic proximities of Indian Mounds, Clifton Gorge, and John Bryan State Park, it may meet the criteria for “Endangered.” Careful scouting of some of the historical locations and similar limestone-dominated areas might turn up some more instances, potentially properly placing it in the “Threatened” category. Regardless of its potential for listing, let’s keep an eye out for this interesting moss!
-Bob Klips