Eastern Flowering Dogwood
Scientific Name: Cornus florida
Taxonomy Group: Vascular Plants
COSEWIC Range: Ontario
COSEWIC Assessment Date and Status Change: April 2007
COSEWIC Status: Endangered
COSEWIC Status Criteria: A3e+4ae; C1+2a(i)
COSEWIC Reason for Designation: A small understory or forest-edge tree present only as small populations within the fragmented woodlots of southern Ontario’s Carolinian forest. The spread of dogwood anthracnose disease has caused dramatic declines in the Canadian populations that reflect similar declines throughout the species’ range in eastern North America. This assessment of risk applies only to wild populations and not to cultivated plants in nurseries, parks, and gardens.
COSEWIC History of Status Designation: Designated Endangered in April 2007.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2009-03-05
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
The Eastern Flowering Dogwood is a small tree measuring 3 to 10 m in height. In larger specimens, the bark is brownish grey and separated into quadrangular plates, giving it the appearance of alligator skin. The main branches are arranged in a clearly tiered pattern around the trunk. The oval leaves are opposite each other on the branches. The small flowers, which grow in clusters at the tips of small branches, are surrounded by four conspicuous white leaves similar to petals. The fleshy, egg-shaped fruit grows in tight clusters. Although similar to the Alternate-leaved Dogwood, the Eastern Flowering Dogwood can be distinguished by the position of its leaves, the presence of white “petals” around its flower clusters, and the colour of its fruit, which is scarlet red as opposed to dark green or blue.
Distribution and Population
The Eastern Flowering Dogwood occurs in eastern North America from southern Michigan, Ontario, and Maine, to eastern Texas and northern Florida. It is common to the deciduous forests of the central and southern United States. Two extremely isolated populations are known to exist in the mountains of eastern Mexico. In Canada, this species is only found in the deciduous forests of southern Ontario: in Oakville just west of Toronto, along the Niagara escarpment through Halton and Hamilton, and in several sites scattered throughout the Niagara region and towards the southwest. The Eastern Flowering Dogwood is particularly plentiful on the sand plain of Norfolk County. From 1975 to 2005, 154 Eastern Flowering Dogwood populations were documented in 12 counties and regions in southern Ontario. The total number of specimens was estimated to be between 1200 and 1300. Certain populations had no more than a single tree, many had from one dozen to several dozen trees, and one population had more than one hundred trees. Several populations have declined significantly (average rate of 7% to 8% per year) since the onset of dogwood anthracnose, a leaf disease that leads to the death of the tree. This has resulted in a massive decline (86.5%) of Canadian populations since the early 1990s.
The Eastern Flowering Dogwood generally grows in the understory or on the edges of mid-age to mature, deciduous or mixed forests. This species is generally found in the drier areas of its habitat, although it is occasionally found in slightly moist environments. The Eastern Flowering Dogwood grows in sandy soil, more or less clayey. The species typically occurs in clusters within larger parcels of apparently suitable, though unoccupied, habitat. Historically, the Eastern Flowering Dogwood occupied a significant portion of the Carolinian forest in southern Ontario. However, large portions of the forest have been cleared to make way for agricultural activities, residential areas, and industrial facilities. This profound transformation resulted in a significant reduction and fragmentation of forest cover and suitable habitat.
The Eastern Flowering Dogwood is a slow-growing tree with a long lifespan. The tree flowers in mid-spring, just as the leaves begin to develop. The large, white, petal-like leaves that surround the flowers make them particularly conspicuous; they attract pollinating insects, thus ensuring that reproduction will occur. Although the flowers have both male and female parts, seed production is optimal when flowers are pollinated with pollen from another flower. The fruit turns red at the end of the summer, once it has matured. Ripe fruits are eaten and dispersed by several bird species and a few mammals species. Seeds germinate in the spring one or two years after dispersal. Germination and the establishment of shoots occur in the forest shade, although exposure to intermediate light levels stimulates growth.
The main threat to this species is dogwood anthracnose, a leaf disease that is new to Ontario. Anthracnose is caused by a microscopic fungus that triggers the massive die-back of leaves, which, in turn, causes the death of trees. This disease has decimated several populations. In fact, only a few populations appear to have been spared to date. In addition to causing massive die-offs, dogwood anthracnose compromises the production of flowers and fruit in surviving specimens. Other threats to the Eastern Flowering Dogwood include the fragmentation and loss of forest land in southern Ontario, particularly in the extreme southwest of Essex County and in the Chatham–Kent region. The deterioration of the dogwood’s habitat reduces the probability that birds can effectively disperse seeds over long distances from occupied habitats to suitable unoccupied habitats.
The Eastern Flowering Dogwood is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
The Eastern Flowering Dogwood is not protected under any provincial law in Ontario.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Eastern Flowering Dogwood (Cornus florida) in Canada
Status Final posting on SAR registry
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
10 record(s) found.
- Reports on the Progress of Recovery Document Implementation (1 record(s) found.)
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Action Plans (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Exceptions (1 record(s) found.)
Reports on the Progress of Recovery Document Implementation
COSEWIC Status Reports
Response Statement - Eastern Flowering Dogwood (2007-12-04)A small understory or forest-edge tree present only as small populations within the fragmented woodlots of southern Ontario’s Carolinian forest. The spread of dogwood anthracnose disease has caused dramatic declines in the Canadian populations that reflect similar declines throughout the species’ range in eastern North America. This assessment of risk applies only to wild populations and not to cultivated plants in nurseries, parks, and gardens.
COSEWIC Annual Reports
COSEWIC Annual Report - 2007 (2007-08-30)2007 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.