The genus name Empetrum comes from the Greek en, which means upon, and petros, which means rock (Fernald 1970). This name alludes to the way this species grows on rocks. The common name black crowberry refers to the black color of the fruits and makes reference to the fact that, at least in the arctic where this plant also grows, birds relish the fruits (Waller and DiGregorio 1997). This plant's Inuit name, paurngait, means "which looks like soot", and refers to the black berries (S. G. Aiken et al 1989).
There are 19 known populations. Nine of these populations are ranked excellent or good. Some of these are quite large with one containing an estimated 250,000 individuals. The overall range of the extant populations is relatively small. All the populations are restricted to the high peaks region of the Adirondacks. There are an additional two populations, also from the high peaks region, that have not been seen in over 85 years but additional survey work is needed before these populations can be determined extirpated. There is also one disjunct population known from the South Fork of Long Island which has not been seen since 1924. This population is believed to be extirpated.
There are no clear data on short-term trends, although trampling by hiker traffic has most likely, at least slightly, reduced the size of many populations in recent years.
The one disjunct population from eastern Long Island has not been seen since 1924. There is strong evidence that it was destroyed due to erosion caused by the ocean. There are two additional populations that have not been seen in over 85 years but additional survey work is needed to determine if these populations are still extant. Therefore, long term trends indicate at least a slight decline in the past 150 years.
At many of the populations trampling by hiker traffic threatens at least parts of the populations. Left unchecked, global climate change is also a threat.
The Summit Steward program which works to inform hikers of the fragile nature of alpine plants is a critical program which is helping to reduce trampling of alpine vegetation. This program and other efforts designed to reduce trampling of alpine meadows are needed.
Additional survey work is needed at the two populations which are only known from historical records to determine if these populations are still extant. Further survey work in the high peaks region may turn up additional populations. Clear and consistent estimates of population size at extant populations is needed to help determine the trend of this species.
In New York, this species occurs on many of the highest summits of the Adirondacks, in alpine meadows sometimes adjacent to krummholz. It is also known at least historically from slightly lower sites on rock ledges and outcrops, and perhaps a bog, in cool microclimates in the high peaks region of the Adirondacks. There is also one disjunct extirpated population that was known from a maritime site on eastern Long Island (New York Natural Heritage Program 2007). Exposed, peaty and rocky areas (Haines and Vining 1998). On rocks (Gleason and Cronquist 1991). Arctic regions, peaty soils in more southern locations, alpine areas of northern New England and New York (Fernald 1970).
In New York this species occurs predominately in the high peaks region of the Adirondacks. It is was also known historically from one population in Suffolk County, Long Island, but that population is believed to be extirpated. New York is at the southern edge of its range.
Empetrum nigrum ssp. hermaphroditum occurs in the northern parts of Europe and Asia as well as Greenland and eastern North America, south to northern Minnesota, Michigan, the coast of Maine, the alpine areas of northern New England and New York, and formerly one disjunct on Long Island (Fernald 1970, Anderberg 1994, New York Natural Heritage Program 2007). Depending on the circumscription of this taxon it is also considered to occur in the arctic regions of western North America south to the alpine areas of northern California to southern Alberta (Fernald 1970).
Black crowberry is a very low trailing shrub that makes an attractive dense ground cover in the exposed alpine areas where it occurs. Its twigs, at least when young, have hairs with glands on the tips. The evergreen leaves are short and needle-like with tiny glandular teeth along the margins. The leaves are mostly without hairs and spread or reflex back from the braches where they arise. The small and inconspicuous flowers occur in the axils of the leaves. The fruits are about .25 to .35 inches in diameter, black, and sometimes have a thin white waxy coating (Fernald 1970, Gleason and Cronquist 1991).
This species is a trailing woody evergreen shrub. The twigs and branchlets especially when young are minutely stipitate-glandular and are not densely white-tomentose or white-villose. The leaves are evergreen, needle-like, and stiff. The flowers are mostly bisexual. The drupes are black and glaucous.
This species can be easily identified throughout the year when snow is not covering it, although, fruits make identification easier.
The other species of Empetrum (E. eamesii ssp. atropurpureum) that occurs in New York and can be present with E. nigrum ssp. hermaphroditum is superficially very similar. It differs in having twigs and brachlets white-tomentose or white-villous and not stipitate glandular, and drupes purple-black. Its new leaves have white hairs along the entire margin.
Harrimanella hypnoides is another alpine plant that is believed to be extirpated in New York. It perhaps could be mistaken for Empetrum nigrum ssp. hermaphroditum when vegetative due to its evergreen needle like leaves. It can be distinguished by its smaller size, its rough margined leaves that arise along the entire stem, and its showy, white, bell-shaped flowers at the tips of stems, which mature into dry capsules.
This plant starts to have fruits in July and these can last into the fall. Therefore, the best time to survey for this species is from July through late October although it can be distinguished vegetatively anytime during the growing season.
The time of year you would expect to find Black Crowberry vegetative, flowering, and fruiting in New York.
Empetrum nigrum ssp. hermaphroditum (Lange ex Hagerup) Böcher
Empetrum nigrum L. sensu stricto was originally used in a broad sense to include North American, European and Asian plants. Hagerup (1927 in Anderberg 1994) transferred hermaphroditic, tetraploid plants to E. hermaphroditum. This included the North American plants that had previously been recognized as E. nigrum. Löve (1960 in Anderberg 1994) also transferred other hermaphroditic tetraploid plants from North America into E. hermaphroditum including E. eamesii sensu stricto and E. atropurpureum. The name E. eamesii took priority and the name E. eamesii ssp. hermaphroditum was used. Recognition that E. hermaphroditum is more closely related to E. nigrum than E. eamesii sensu stricto or E. atropurpureum, facilitated the transfer to E. nigrum as E. nigrum ssp. hermaphroditum. Anderberg's (1994) work supports this idea. More work will help to resolve at what rank (species or subspecies) the two taxa (E. nigrum sensu stricto and E. hermaphroditum) should be recognized. Gleason and Cronquist (1991) recognize E. hermaphroditum at the subspecific rank of variety: E. nigrum var. hermaphroditum (Hagerup) T. Sørensen. Li et al. (2002) show that the Empetraceae is monophyletic. Work by Judd and Kron (1993) indicate that the Empetraceae is derived from within Ericaceae and therefore if a broad Ericaceae concept is followed Empetraceae needs to be included for Ericaceae to be monophyletic. Therefore, they lump the Empetraceae into Ericaceae.
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.
Aiken, S.G., M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 2003. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arctic
Anderberg, A.A. 1994. Phylogeny of the Empetraceae, with Special Emphasis on Character Evolution in the Genus Empetrum. Systematic Botany 19: 35-46.
Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.
Haines, A. and T.F. Vining. 1998. Flora of Maine, A Manual for Identification of Native and Naturalized Vascular Plants of Maine. V.F.Thomas Co., Bar Harbor, Maine.
Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.
Judd, W.S.and K.A. Kron. 1993. Circumscription of Ericaceae (Ericales) as Determined by Preliminary Cladistic Analyses Based on Morphological, Anatomical, and Embryological Features. Brittonia 45: 99-114.
Li, J., J. Alexander III, T. Ward, P.D. Tredici, and R. Nicholson. 2002. Phylogenetic relationships of Empetraceae inferred from sequences of chloroplast gene matK and nuclear ribosomal DNA its region. Molecular Phylogenetics and Evolution 25: 306-315.
New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.
New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.
Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.
Waller, J. and M.J. DiGregorio. 1997. New England's Mountain Flowers. A High Country Heritage. Mountain Press Publishing Company, Missoula, Montana.
Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research http://www.fccdr.usf.edu/. University of South Florida http://www.usf.edu/]. New York Flora Association http://www.nyflora.org/, Albany, New York
Information for this guide was last updated on: January 31, 2008
Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Empetrum nigrum ssp. hermaphroditum. Available from: https://guides.nynhp.org/black-crowberry/. Accessed January 15, 2019.