Moss Musings –
Leratia exigua (Sull.) Goffinet – New to Ohio, but Is It Native?

In September 2019, during the Fall Foray in Ashtabula County, I collected Platygyrium repens from the bark of a red maple tree (Acer rubrum). While examining the material with the dissecting scope, I noticed a small moss that I assumed was a member of the family Pottiaceae. Unable to give it a name, I put the specimen aside, marked “to be determined”. During the past couple of years, I went back to the collection but quickly gave up because I made no progress.

This fall, I took the specimen to my moss mentor, Dr. William Buck, retired curator at the New York Botanical Garden. He pointed out all the reasons that it was not in the Pottiaceae, but in the Orthotrichaceae. Although the specimen was sterile, members of the genus
Orthotrichum that have superficial stomata also have elongate and somewhat nodulose basal cells. This helped narrow down the group (capsules with superficial or immersed stomata) to which the specimen belonged. The plants were claviform because of the appressed leaves, and the leaves had an abundance of brood bodies. Bill identified this material as Orthotrichum exiguum Sull., now Leratia exigua (Sull.) Goffinet.

Needless to say, I’m always excited about finding a bryophyte species new to Ohio. Upon checking the distribution in the Consortium of North American Bryophyte Herbaria (https://bryophyteportal.org) (accessed 16 November 2021), I found that this species had been collected in North America only 12 times. Between 1850 and 1951, there are collections from Tennessee, North Carolina, South Carolina, Georgia, and Oklahoma. Crum and Anderson (1981. Mosses of Eastern North America, Vol. 2, Columbia University Press), added a specimen from Virginia. Crum and Anderson make no mention of the Oklahoma specimen.

The Ohio locality is disjunct from the southern populations. It was found growing on a red maple tree in a parking lot for a boat launch along Lake Pymatuning. Wind currents, typically blowing from the south toward the northeast, probably would not have transported spores. A possibility could be birds, or it could have been on a boat or boat trailer. Another possibility is that the red maples in the parking lot (probably planted) came from a nursery within the region where the moss is native.

Is Leratia exigua native to Ohio? Are there overlooked populations between Tennessee and northeastern Ohio? For now, Andreas 19801 is housed in the herbarium at the New York Botanical Garden. In the future, I’ll spend more time examining Platygyrium populations on red maple trees.

-Barbara K. Andreas