Bryum rubens from Niagara Falls, New to New York State
P. M. Eckel and J. Shaw
Res Botanica, a Missouri Botanical Garden Web site

Originally published in Bryologist 94: 80-81. 1991.

Republished with permission.

The Bryologist 94(1), 1991, pp. 80-81

Copyright 1991 by the American Bryological and Lichenological Society, Inc.

Bryum rubens from Niagara Falls, New to New York State


Clinton Herbarium, Buffalo Museum of Science, Buffalo, NY 14211


Department of Biology, lthaca College, lthaca, NY 14850

Abstract. Bryum rubens Mitt. is reported new to the moss flora of New York State, from the fifth station known for North America. This taxon is most likely a weedy introduction from Europe.

Ketchledge (1980) listed Bryum tenuisetum Limpr. in the New York State flora as only a literature report, without a corresponding bibliographic citation. In a manuscript in preparation regarding the rare mosses of the state for the New York Natural Heritage Program inventory, Clemants and Ketchledge consider the demographic status of B. tenuisetum in the New York flora unknown. The taxon is not listed as globally rare. They also indicate that there is some question as to its taxonomy, perhaps following Crum and Anderson (1981) who provisionally grouped Bryum tenuisetum in a complex of gemmiparous taxa under B. radiculosum Brid., S.I., pending further study.

A. C. Crundwell kindly identified for us a recently collected specimen of Bryum from Niagara Falls, New York, as B. rubens Mitt. He emphasized the distinctive lax areolation of the specimen and numerous additional characters setting it off from other species in the complex, such as B. radiculosum, B. klinggraeffii, and B. micro-erythrocarpum. Bryum rubens has not previously been reported from the state of New York, and ours is the fifth collection known from North America (Crundwell & Whitehouse 1978).


The specimen from Niagara Falls keyed out satisfactorily in both the Crum and Anderson key to the segregate species listed under B. radiculosum and in Crundwell and Nyholm's key to the B. erythrocarpum complex (1964). According to Crum and Anderson's key, B. rubens differs from B. tenuiseturn by the latter's lemon-yellow rhizoidal gemmae and smaller size, compared with the red gemmae and generally more robust plants of the former species. Leaves of B. rubens also have a distinct border. In the Niagara Falls specimen the border is generally one cell wide, with the cells elongate and not differentiated by color or cell-wall thickness. The leaf border of B. rubens varies from well developed in robust plants to absent in depauperate material (Crundwell & Nyholm 1964).


Crundwell and Nyholm (1964) found that species in the B. erythrocarpum complex showed indications that "plants with large or medium-sized red gemmae can be separated into two groups by their pH reactions." In the herbarium packet, plants of B. rubens from Niagara Falls had reddish stems, the leaves were green to yellowish-green with reddish costae, and the gemmae were red-violet. One plant, when wetted with a solution of HCI, had stem and leaves paler green to lemon-yellow, and the gemmae clear red-orange. The stem and leaves of a second plant, in 2% KOH, turned light orange becoming darker (brownish) and the gemmae deep, obscure (black-)violet. Upon letting the slides stand for an hour, during which the water evaporated but the stems remained wet, the color differences became extreme and unambiguous, the red-orange of the gemmae soaked in HCI tending to be more orange than red-orange, the gemmae in KOH becoming ever deeper (blacker) violet.


This color reaction to acid-alkaline solutions conforms to that described by Crundwell and Nyholm (1964). Subjecting doubtful specimens in the B. erythrocarpum complex (Crundwell & Nyholm 1964) to acid-alkaline wetting agents may indeed become a useful tool in separating these taxa by making more emphatic the color characters which, to a beginner, may seem arbitrary and subjective.


As mentioned by Crum and Anderson (1981), Crundwell and Nyholm (1964), and Crundwell and Whitehouse (1978), the spotty distribution of B. rubens in North America, that is, an extreme disjunction between California and Maryland with in- termediate stations in Tennessee and Oklahoma, among other evidence, supports the contention that this species and other taxa in the B. erythrocarpum complex are weedy introductions to the North American moss flora. Specimen data supporting the occurrence of the species in North America recorded by Crundwell and Whitehouse (1978) demonstrate an association with disturbed habitats. In Europe the species is associated with ephemeral habitats, in old fields, ditches, and road embankments, and it is the most common of the species in the B. erythrocarpum complex in Great Britain (Crundwell & Nyholm 1964). The limestone gorge and other habitats adjacent to the cataracts of the Niagara River, actually a strait linking Lakes Erie and Ontario, with its exposure to strong prevailing winds, extensive horticultural plantings, and visitation by more than four million people annually, provides a favorable environment for the establishment of introduced diaspores.


U.S.A. NEW YORK. NIAGARA CO.: City of Niagara Falls, Green Island just north of Goat Island in the Niagara River; old dolomite ballast on south side, wet to moist river margin, with Pottia truncata, Phascum cuspidatum, Amblystegium tenox, P. M. Eckel & M. P. Eckel 9004156 (BUF; HERB A. C. CRUNDWELL; ITHACA COLLEGE).



Grateful acknowledgment is made to A. C. Crundwell and R. H. Zander for their helpful comments. This research was funded in part by a grant from the Niagara Frontier Chapter of the Adirondack Mountain Club and by the Niagara Frontier State Park Commission, a division of the New York State Department of Parks, Recreation and Historic Preservation, to the senior author.




CRUM,H.A.&L.E.ANDERSON. 1981. Mosses of Eastern North America. New York.


CRUNDWELL, A. C. & E. NYHOLM. 1964. The European species of the Bryum erythrocarpum complex. Transactions of the British Bryological Society 4: 597-637.


& H.L.K.WHITEHOUSE. 1978. Bryum rubens in North America. THE BRYOLOGIST 81: 323-324.


KETCHLEDGE,E.H. 1980. Revised Checklist of the Mosses of New York State. New York State Museum Bulletin 440. Albany.