CPC National Collection Plant Profile

Corema conradii

Jean Baxter

Heading for profile page
CPC Home Join now
About CPC
CPC National Collection
Conservation Directory Resources
Invasive Plant Species Plant News
Plant Links Participating Institutions
Search CPC
Search    Alphabetical List    Reference Finder    CPC Home

CPC National Collection Plant Profile

Corema conradii

Common Names: 
broom crowberry, broom-crowberry, poverty grass
(Torr.) Torr. ex Loud.
Growth Habit: 
Subshrub, Shrub
CPC Number: 


Profile Links

Corema conradiienlarge
Photographer: Jean Baxter
Image Owner: New England Wildflower Society

Corema conradiienlarge
Photographer: John A. Lynch
Image Owner: New England Wildflower Society

Corema conradii is Fully Sponsored
Primary custodian for this plant in the CPC National Collection of Endangered Plants is: 
Irina Kadis contributed to this Plant Profile.

Corema conradii

Named after its discoverer, S. White Conrad (1779-1831), Corema conradii is one of the rarest plants in Massachusetts. It is a low, densely branched evergreen dioecious shrub with heath-like leaves and purplish flowers (Brown 1913, Norton 1913, Campbell and Hyland 1975). It belongs to a small genus distributed on both sides of the Atlantic and represented by only two species: one in Spain and Portugal, the other, C. conradii, on the Atlantic Coast of eastern North America (McEwen 1894, DiGregorio and Wallner 1989).

Distribution & Occurrence

State Range
New Jersey
New York
State Range of  Corema conradii
  Corema is a plant of coastal plains. It grows on sandy soil, open sand, or siliceous rocky plateaus, ledges, and summits (Fernald 1921, Dunwiddie 1990, Dunwiddie et al. 1997). On open hilltops, it is found in pitch pine (Pinus rigida) stands, forming a springy carpet in pine barrens (Sorrie 1987). All of these habitats have relatively open light conditions, a requirement for the plant. This may be due to disturbance, often in the form of infrequent fire (Sorrie 1987).

  This species has a disjunct distribution (meaning a few, widely separated populations) occurring on sandy or rocky coasts from Nova Scotia to Massachusetts, in the New Jersey pine barrens, and in the Shawangunk Mountains of New York (Program 1985, Dunwiddie 1990).

Newfoundland--most abundant and of largest size
Quebec, Canada (Magdalen Is.)
Prince Edward I.
Nova Scotia--most abundant and of largest size

Maine: coastal hills north of Camden (not on the sand)
Hancock Co.
Lincolnville, Knox Co.
Lincoln Co.
Sagadahoc Co.
Cumberland Co.

southeastern Massachusetts--
Western Cape Cod Locations:
1. North of DeGrass Rd., South Mashpee (open hilltops, under pitch pines)
2. North Falmouth
3. Osterville
4. Dennis
5. West Brewster
6. Eastham--Provincetown (on open sand)--most abundant
7. Lowell Holly Reservation
8. Wellfleet (on the sand)
Martha's Vineyard

New York:
mostly near the cost
inland in Ulster Co.
Shawangunk Mts. (southern N. Y.)--"Gertrude's Nose" Promontory (not on the sand)

New Jersey: pine barren area

Number Left
  Remaining sites and populations are largely unknown. The greatest abundance of C. conradii is known from New Jersey's Pinelands (Good et al. 1979). In 1983, populations were surveyed on the Provincetown Peninsula; occurrences were observed in relict dune ridges, pine barrens and along road embankments (LeBlond 1983).


Global Rank:  
Guide to Global Ranks
Federal Status:  
Guide to Federal Status
Recovery Plan:  

State/Area Protection
  State/Area Rank Status Date  
  Canada nothing 12/5/2001  
  Massachusetts SC 6/15/2000  
  New Jersey S1 E 9/1/2001  
  New York S1 E 4/1/2001  

Conservation, Ecology & Research

Ecological Relationships
  Fire directly kills adult plants but results in an abundant establishment of seedlings (Dunwiddie 1990). Plants can be extensively browsed by deer.

  Lack of frequent fire causing habitat succession
Herbivory, especially deer browsing
Shoreline or cliff erosion
Human trampling
Development in the form of quarrying, sand mining, housing or road construction

Current Research Summary
  The reproductive investment of male and female plants has been studied by Rocheleau and Houle (2001).
Individuals at the Botanic Garden of Smith College have studied germination of this species with only limited success. (2002)
Propagation by seed: all treatments have shown low germination rates. Although seeds are abundant in nature, the natural mechanism that brings about germination is not yet known. Smoke treatment may bring about a higher germination rate.
Propagation from hardwood cuttings: Oct-Jan in 50/50 sand-perlite under poly cover, with 2,500-500 ppm K-IBA treatment yields 80%+ rooting.

Current Management Summary
  C. conradii is partially protected within state parks. For example, populations in the pine plains community in New Jersey and relict dune ridge areas in Provincetown are protected (Russel 1994, LeBlond 1983).

Research Management Needs
  C. conradii needs to be consistently monitored and fire ecology in relation to all life history stages needs to be investigated (Mallik and Gimingham 1985, Fimbel and Kuser 1993).

Ex Situ Needs


Books (Single Authors)

Campbell, C.S.; Hyland, F. 1975. Winter Keys to Woody Plants of Maine. Orono, Maine: University of Maine Press.

DiGregorio, M.; Wallner, J. 1989. A Vanishing Heritage: Wildflowers of Cape Cod. Missoula, MT: Mountain Press Publishing Company.

Gleason, H.A. 1952. The New Britton and Brown illustrated flora of the northeastern United States and adjacent Canada. New York, NY: Hafner Press. 1732p.

Harshberger, J.W. 1989. The Vegetation of the New Jersey Pine Barrens. New York City: Dover Publications, Inc. 329p.

Scoggan, H.J. 1978. The Flora of Canada. National Museums of CA, Publications in Botany.

Books (Sections)

Good, R.E.; Good, N.F.; Andreson, J.W. 1979. The pine barren plains. In: Forman, R.T.T., editor. Pine Barrens: Ecosystem and Landscape. Academic Press. New York. p 283-295.

Kartesz, J.T. 1999. A synonymized checklist of the vascular flora of the U.S., Canada, and Greenland. In: Kartesz, J.T.; Meacham, C.A., editors. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden. Chapel Hill, NC.

Electronic Sources

(2002). New York Metropolitan Flora Project: Metropolitan Plant Encyclopedia. [Searchable Web site] Brooklyn Botanic Garden. http://www.bbg.org/sci/nymf/encyclopedia/contents.htm. Accessed: 2002.

MANHESP. (1993). Massachusetts Endangered Plants Fact Sheets. Massachusetts Natural Heritage and Endangered Species Program; Division of Fisheries and Wildlife, Westborough, Massachusetts. http://www.state.ma.us/dfwele/dfw/nhesp/nhfactplt.htm. Accessed: 2002.

Journal Articles

Brown, S. 1913. Corema conradii Torrey. Bartonia. 6: 1-7.

Dunwiddie, P.W. 1990. Rare plants in coastal heathlands: Observations on Corema conradii (Empetraceae) and Helianthemum dumosum (Cistaceae). Rhodora. 92, 869: 22-26.

Dunwiddie, P.W..; Zaremba, R.E..; Harper, K.A.. 1997. A Classification of Coastal Heathlands and Sandplain Grasslands in Massachusetts. Rhodora. 98, 894: 117-145.

Fernald, M.L. 1911. A Botanical Expedition to Newfoundland and Southern Labrador. Rhodora. 13, 151: 109-162.

Fernald, M.L. 1921. Expedition to Nova Scotia. Rhodora. 13: 136-273.

Fernald, M.L. 1921. Gray Herbarium Expedition to Nova Scotia. Rhodora. 13: 136-273.

Fimbel, R.A.; Kuser, J.E. 1993. Restoring the pygmy pine forests of New Jersey's Pine Barrens. Restoration Ecology. 4: 117-129.

Fogg, J.M. 1930. The Flora of the Elizabeth Islands, Massachusetts. Rhodora. 32: 167-179.

Grandtner, M.M. 1967. Les ressources vegetales des Iles-de-la-Madeleine. Fonds de recherches forestieres de l'Universite Laval. Bulletin No. 10

Gray, A. 1848. Chloris Boreali-Americana. Corema and other North American genera, 1-14. Mem. American Academy of Arts and Sciences. 3: 1-56.

Kim, K.H.; Nilsson, S.; Praglowski, J. 1988. A note on the pollen morphology of the Empetraceae. Grana. 27: 283-290.

Kim, K.H.; Nilsson, S.; Praglowski, J. 1988. A note on the pollen morphology of the Empetraceae. Grana. 27: 283-290.

Mallik, A.U.; Gimingham, C.H. 1985. Ecological effects of heather burning. II. Effects on seed germination and vegetative regeneration. Journal of Ecology. 73: 633-644.

McEwen, M. 1894. The comparative anatomy of Corema alba and Corema conradii. Bulletin of the Torrey Botanical Club. 21: 277-285.

Moore, D.M.; Harborne, J.B.; Williams, C.A. 1970. Chemotaxonomy, variation and geographical distribution of the Empetraceae. Botanical Journal of the Linnean Society. 63: 277-293.

Norton, A.H. 1913. Plants from islands and coast of Maine. Rhodora. 15: 137-143.

Redfield, J.H. 1884. Corema conradii and its localities. Bulletin of the Torrey Botanical Club. 11: 97-101.

Redfield, J.H. 1889. Corema in New Jersey. Bulletin of the Torrey Botanical Club. 16: 193-195.

Rocheleau, A.F; Houle, G. 2001. Different cost of reproduction for the males and females of the rare dioecious shrub Corema conradii (Empetraceae). American Journal of Botany. 88, 4: 659-66.

Russell, E.W.B. 1994. The use of theory in land management decisions: the New Jersey Pine Barrens. Biological Conservation. 68: 263-268.

Smiley, D. 1939. Field trip of September 10 to the Shawangunks. Torreya. 39: 20-22.

Smiley, D. 1940. Weekend trip of May 3 to 5 to Mohonk Lake. Torreya. 40: 131-132.

Smith, A.H. 1882. A New Station for Corema conradii, Torr. Torrey Procedings of Philadelphia Academy. 35.

Smith, C.E. 1880. Corema conradii. Botanical Gazette. 7: 77.

Smith, C.E. 1882. New Station for Corema conradii. Bulletin of the Torrey Botanical Club. 9: 83.

Sorrie, B.A. 1987. Notes on the rare flora of Massachusetts. Rhodora. 89, 858: 113-196.

Stone, W. 1911. General notes: Corema conradii in Ocean Co., N.J., east of the plains. Bartonia. 3: 26.

Torrey, R.H. 1932. The Corema conradii station on Shawangunk Mountain. Torreya. 32: 97-100.

Williamson, G.B.; Obee, E.M.; Weidenhamer, J.D. 1992. Inhibition of Schizachyrium scoparium (Poaceae) by the allelochemical hydrocinnamic acid. Journal of Chemical Ecology. 18: 2095-2105.

Wood, C.E.; Channell, R.B. 1957. The Empetraceae and Diapensiaceae of the southeastern United States. Journal of the The Arnold Arboretum of Harvard University. 40: 161-167.

Woodford, E.M. 1979. Northern Broom-Crowberry in the New Jersey Pine Barrens. New England Wild Flower Notes. winter


2002. Seed germination in Corema conradii. Northampton, MA: The Botanic Garden of Smith College.

Clemants, S. 1997. Broom Crowberry Technical Page. Brooklyn, NY: Brooklyn Botanic Garden. p.2. Web page.

Huth, P.; Smiley, D. 1982. Chronology of Corema conradii in the Shawangunk Mountains-the only New York State location, 1881 - 1981. Mohonk Preserve, Inc.

LeBlond, R. 1983. Survey of the distribution of Corema conradii on the Provincetown peninsula. Unpublished report of the Massachusetts Natural Heritage Program.

Nicholson, R.; Alexander, J. Not dated. Germination trials with Corema conradii. Massachusetts Heritage Program.

Obee, E.M. 1994. Element Stewardship Abstract for Corema conradii. Trenton: State of New Jersey; Department of Environmental Protection. p.10. TNC Stewardship Abstract. 018.

Program, Massachussets Natural Heritage. 1985. Massachussets Rare and Endangered Plants: Corema conradii. Westborough: Natural Heritage & Endangered Species Program, Division of Fisheries & Wildlife. p.2.

Stone, W. 1912. The plants of southern New Jersey with special reference to the flora of the Pine Barrens and the geographic distribution of the species. New Jersey State Museum Annual Report for 1910. p.828.

Zaremba, R. 1984. Corema conradii-Broom crowberry. Massachusetts Heritage Program.


Rocheleau, Anne-Francoise. 1998. Biologie de la Reproduction du Coreme de conrad (Corema conradii), un Arbuste Dioique en Milieu Dunaire aux Iles-de-la-madeleine. [M.S. Thesis]: Universite Laval (Canada). 83p.

  This profile was updated on 9/28/2010
New Mexico
North Dakota
South Dakota
South Carolina
North Carolina
West Virginia
New Jersey
Rhode Island
New Hampshire
New York
New York