Species Profile

Drooping Trillium

Scientific Name: Trillium flexipes
Taxonomy Group: Vascular Plants
Range: Ontario
Last COSEWIC Assessment: April 2009
Last COSEWIC Designation: Endangered
SARA Status: Schedule 1, Endangered


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Quick Links: | Taxonomy | Photo | Description | Distribution and Population | Habitat | Biology | Threats | Protection | Recovery Initiatives | Recovery Team | National Recovery Program | Documents

Image of Drooping Trillium

Drooping Trillium Photo 1

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Taxonomy

No varieties or subspecies have been formally recognized, but one of the many forms of the Drooping Trillium Trillium flexipes has been named T. flexipes forma walpolei. This reddish or maroon form is likely a hybrid with the Red Trillium (T. erectum).

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Description

The Drooping Trillium is a perennial herb. Its erect, robust stem is 15 to 60 cm tall and is surmounted by three large leaves without a stalk, or petiole. They are up to 20 cm long and wide, narrow from near the middle to the base, and taper to a long point. A single plant may have one or more stems growing from a horizontal underground stem, or rhizome. Not all stems or individuals bear flowers. The solitary flower is supported by a stalk, or peduncle, that is 3 to 12 cm long arising from the centre of the leaves. As the name of the Drooping Trillium suggests, the peduncle is often curved, but is sometimes horizontal or erect. The flower has three large spreading petals, 2 to 5 cm long, and often has a stale or musty fragrance. The petals are normally white, but can be reddish or maroon in the forma walpolei. The lance-shaped sepals are about equal in length to the petals. The fruits are berrylike, rosy red to purplish, fragrant and very juicy at maturity. They are 2 to 3.5 cm long and 1 to 3 cm wide. The Drooping Trillium can have a very similar appearance to two species found in British Columbia: the Red Trillium and the Nodding Trillium. The Drooping Trillium can be differentiated from these two species by its large spreading petals and by the cream-coloured tips of its stamens. It can also be distinguished from the Nodding Trillium by its larger leaves, and from the Red Trillium by the white lower part of the female reproductive organ.

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Distribution and Population

The Drooping Trillium occurs in Ontario and in 17 states in the north-central and eastern United States. In Canada, the species was known historically from seven sites in southern Ontario, but is thought to persist at only two locations. The two confirmed extant sites are along the Sydenham River at Strathroy and along the Thames River in the Municipality of Dutton/Dunwich. In Canada, a total of 1465 flower stems were reported in 2007, which represents a smaller number of individual plants (perhaps 500 to 1000), because there are one to several flowering stems per plant. This number does not include the small number of individuals without flowers, which are difficult to distinguish from the other similar trilliums. Numbers appear to be stable or increasing at the two extant sites. The number of flowering stems at the Strathroy site has apparently doubled since 1989, and the number of flowering individuals at the Dutton/Dunwich site increased from 75 in 1993 to 453 in 2007. The increase may be the result of the maturation of individuals that were not flowering in 1993 or a natural variation in numbers.

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Habitat

The Drooping Trillium is typically found in mature deciduous forests, usually crossed by streams. The open spring canopy and more closed summer canopy conditions at the two extant sites in Ontario suggest that the species is dependent on fairly high light intensity during the early stages of growth and during the flowering period. It grows on dry, neutral, well-drained, sandy clay soils. The species favours the slightly higher elevations of microsites on the floodplain, which are better drained and warmer than average. It may also benefit from periodic disturbance caused by flooding. The Strathroy site along the Sydenham River has undergone some timber harvesting in the past, but it appears to have remained relatively unchanged since the initial discovery of this population almost 100 years ago. Its bottomland location within a small floodplain made it no doubt undesirable for agricultural use. However, a few suitable sites were lost by the development of a golf course. Selective logging of large-diameter trees occurred at the Dutton/Dunwich site in 2003.

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Biology

In Canada, the Drooping Trillium is a herbaceous plant that typically flowers from mid-May to early June. This perennial can take 10 years to flower and can live for several decades. Each individual plant has one to several flowering stems. Their mating system is not well understood, but pollination seems to be accomplished by insects that carry the pollen from one flower to another. Hybridization of the Drooping Trillium with the Red Trillium and White Trillium has been observed in natural populations. Reproduction is primarily sexual with ants playing a role in short-distance dispersal of seeds. The seeds must remain in the soil for two seasons of cold to germinate. The species can also reproduce vegetatively by rhizomes. Juveniles and mature plants of all trillium species are susceptible to a fungus that attacks the leaves and weakens the plant. Deer strip the leaves, flowers and fruit of the trillium, leaving behind only the bare stalks. These herbivores may also disperse seeds over considerable distances, provided the seeds survive passage through the animal’s digestive tract and are voided in suitable habitat.

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Threats

Habitat loss and degradation caused by urban and agricultural development are the main current threats to Canadian populations. Habitat loss due to expanding urban development caused the extirpation of the historic populations at London and the two Essex County sites. The relatively small area occupied by the Dutton/Dunwich population renders it particularly vulnerable to habitat loss or degradation. Trampling from increased and inappropriate recreational trail use threatens the Strathroy population. Where the trail passes directly through the population, inadvertent damage to trailside plants has occurred from trampling by hikers, mountain bikers, dog-walkers, and dogs running off-leash. In addition, the unauthorized use of the trail network by all-terrain vehicles does considerable damage. Garlic Mustard, exotic honeysuckles and other invasive species are a threat to the two Canadian populations. Browsing by White-tailed Deer is also a threat, particularly for the Municipality of Dutton/Dunwich population, which is very small. Disease caused by various organisms, including fungi, are a potential threat to Drooping Trillium populations.

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Protection

Federal Protection

The Drooping Trillium 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.

In Ontario, Drooping Trillium is protected under the provincial Endangered Species Act, 2007, which prohibits harming or killing the species or damaging or destroying the habitat upon which it depends directly or indirectly. The Provincial Policy Statement issued under Ontario’s Planning Act also prohibits development and site alteration in the significant habitats of endangered species. One of the Canadian populations is largely protected within St. Clair Region Conservation Authority land at Strathroy. The other is on private land. A recovery strategy is in the final stages of preparation.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.

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Recovery Initiatives

Status of Recovery Planning

Recovery Strategies :

Name Recovery Strategy for the Drooping Trillium (Trillium flexipes) in Canada
Status Final posting on SAR registry

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Recovery Team

Carolinian Woodland Plants Recovery Team

  • Jarmo Jalava - Chair/Contact - Other
    Phone: 705-760-2823  Send Email

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Documents

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.

6 record(s) found.

COSEWIC Status Reports

  • COSEWIC Assessment and Update Status Report on the Drooping Trillium Trillium flexipes in Canada (2009)

    Drooping Trillium (Trillium flexipes) is a member of the Liliaceae, the lily family. No varieties or subspecies have been formally recognized, but one of the many forms has been named, forma walpolei. This reddish or maroon form is likely a hybrid with Red Trillium (Trillium erectum). Drooping Trillium can usually be differentiated from other co-occurring Trillium species by the absence or near absence of leaf stalks and slightly drooping flowers with large, spreading, white petals and a white, ovoid ovary with prominent stigmas.

COSEWIC Assessments

  • COSEWIC Assessment - Drooping Trillium (2009)

    Drooping Trillium (Trillium flexipes) is a member of the Liliaceae, the lily family. No varieties or subspecies have been formally recognized, but one of the many forms has been named, forma walpolei. This reddish or maroon form is likely a hybrid with Red Trillium (Trillium erectum). Drooping Trillium can usually be differentiated from other co-occurring Trillium species by the absence or near absence of leaf stalks and slightly drooping flowers with large, spreading, white petals and a white, ovoid ovary with prominent stigmas.

Response Statements

  • Response Statement - Drooping Trillium (2009)

    A showy perennial species currently present at only two small locations in southern Ontario. It has not been found at five additional sites where it was documented historically. This riparian species is at on-going risk of habitat degradation from the invasion of exotic plants. It is also at risk from recreational activities and the effects of stochastic events due to its small population size.

Recovery Strategies

  • Recovery Strategy for the Drooping Trillium (Trillium flexipes) in Canada (2016)

    The Minister of the Environment is the competent minister for the recovery of the Drooping Trillium and has prepared the federal component of this recovery strategy (Part 1), as per section 37 of SARA. SARA section 44 allows the Minister to adopt all or part of an existing plan for the species if it meets the requirements under SARA for content (sub-sections 41(1) or (2)). The Ontario Ministry of Natural Resources (now the Ontario Ministry of Natural Resources and Forestry) led the development of the attached recovery strategy for the Drooping Trillium (Part 2) in cooperation with Environment Canada.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2009 (2009)

    2009 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.

Recovery Document Posting Plans

  • Environment and Climate Change Canada's Three-Year Recovery Document Posting Plan (2016)

    Environment and Climate Change Canada’s Three-Year Recovery Document Posting Plan identifies the species for which recovery documents will be posted each fiscal year starting in 2014-2015. Posting this three year plan on the Species at Risk Public Registry is intended to provide transparency to partners, stakeholders, and the public about Environment and Climate Change Canada’s plan to develop and post these proposed recovery strategies and management plans. However, both the number of documents and the particular species that are posted in a given year may change slightly due to a variety of circumstances. Last update March 31, 2017