Note on Taxonomy for Corydalis scouleri: A member of the Fumariaceae family (to which bleeding heart also belongs), this species is also referred to as “Scouler's fumewort” (E-Flora/USDA). Other
Distribution: Elevation: 0-200 m This species is generally found in coastal forests west of the Cascades from Northwest Oregon through Washington to the northern extent of its range on Southwest Vancouver Island. Main populations on the Coast Region are found in the Nitinat watershed Klanawa River valley and Kissinger Lake area to the west of Cowichan Lake (Hartwell & Paige 2004, COSEWIC 2006). This species may be more widely distributed than presently documented and may potentially have populations in the Lake Cowichan and Walbran valley watersheds (Hartwell & Paige 2004, COSEWIC 2006).
Description: Height 400-1200 mm A tall perennial herbaceous plant arising from thick rhizomes with hollow stems which can be branched or unbranched . Scouler’s corydalis often forms extensive colonies in the forest understory. The blue-green 20-80 mm long leaves have a powdered or waxy whitish to blue appearance and are usually found in threes along the middle of the stem. Flowers of this species are one of the most distinct features consisting of 15-35 thin tubular light pink flowers arranged irregularly along a single stem. Flower produce an ovoid capsule 10-15 mm long containing shiny black seeds (Hartwell & Paige 2004, COSEWIC 2006).
Look’s Like? Other species in this genus such as pink corydalis have similar leaf physiology. However pink corydalis has smaller tubular flowers with bright yellow tips and the plant arises from a taproot while Scouler’s corydalis emerges from a rhizome. Another possible (cursory) group of look-alike species are hedge-nettle (Mexican hedge-nettle, Cooley’s hedge-nettle). While these species have distinctly different leaf and stem structure, hedge-nettle are similar in height, have spikes of pink tubular flowers and are often found in similar moist streamside habitats.
Primary Habitat: Scouler’s corydalis is associated with well shaded nutrient rich moist soils found within riparian forests of primarily mature deciduous hardwoods (red alder, big leaf maple) and conifers (Sitka spruce, western hemlock). Associated understory species include sword fern and salmonberry. Adjacent flowing waters can range from small streams to large rivers (Hartwell & Paige 2004, COSEWIC 2006).
Secondary Habitat: While this species has a preference for more organic and well vegetated riverine sediments, it will also colonize coarser floodplain deposits(Hartwell & Paige 2004, COSEWIC 2006).
Critical Features: Moisture, shade and nitrogen rich soils appear to be the key features for populations of this species to persist. Adjacency to flowing waters may potentially be a mechanism for seed dispersal (Hartwell & Paige 2004, COSEWIC 2006).
Seasonal Life Cycle
Jan / Feb / Mar / Apr / May / Jun / Jul / Aug / Sep / Oct / Nov / DecThis species appears able to reproduces well vegetatively from rhizomes resulting in extensive clones with numerous stems arising from a single plant. Sexual reproduction by way of seeds is possible but requires pollination by another separate clone and at times only flowers at the terminal end of the stem reproduce. As well plants take 4 or more years to reach flowering stage. Once produced however capsules burst open with some force dispersing seeds over a wide area.
Habitat Guild: this species has a strong association with mature mixed forests and flowing waters
Threats
q While the typical riparian habitat and associated plant communities for this species are widely available on the Coast Region population distribution appears limited to the certain valleys on southwest Vancouver Island, likely due to limited capacity to reproduce sexually. Reproductive limitations may also create potential genetic heterogeneity for existing populations, making this species vulnerable to disease.
q This species dies back and becomes dormant in summer making it hard to detect. Streamside activities such as trampling from outdoor recreation activities in late summer may impact rhizome integrity.
q While generally protected within required riparian retention buffers in cutblocks, hazard tree and woody debris management (e.g. removal and thinning) may impact rhizome integrity. Thinning may effect shade levels and microclimates.
q This species preference for floodplain habitats makes it vulnerable to flooding and erosion impacts.
q Removal through illegal collection.
q Key Conservation & Management Objectives
q While generally considered stable, data are needed to fully describe critical habitat attributes and threats. A targeted inventory is needed to determine if undiscovered populations exist elsewhere within the Coast Region (i.e. southwest Vancouver Island).
q Ensure existing data on distribution and occurrence is utilized for land use and resource acitivities.
q Conduct outreach to raise awareness of this species and how to identify it to improve distribution knowledge
q Monitor existing populations on an ongoing basis to assess viability and reduce potential disturbance from land use activities.
q Meet objectives for this species and the conservation of its habitat as set out in the IWMS riparian management guidelines and consider increasing the number of present Wildlife Habitat Areas (WHA’s) for this species under the Forests and Range Practices Act to protect new populations if they are identified.
q Sightings, specimens, or observations of activities threatening its habitat should be reported to the regional Species at Risk Biologist at the Ministry of Environment office.
Main References/Literature Cited
COSEWIC 2006. COSEWIC assessment and update status report on the Scouler’s corydalis Corydalis scouleri in Canada. Committee on the Status of
Endangered Wildlife in Canada. Ottawa. vii + 24 pp.
Hartwell, Sharon and Kathy Paige. 2004. Accounts and Measures for Managing Identified Wildlife – Accounts V. Scouler’s Corydalis.
International Forest Products Limited and BC Ministry of Environment. 2003. A Field Guide to Species at Risk in the Coast Forest Region of British Columbia
Develop With Care: Environmental Guidelines for Urban and Rural Land Development in British Columbia.
BC Species & Ecosystems Explorer (BC Conservation Data Center Summary Report)
NatureServe Explorer
Committee on the Status of Endangered Wildlife in Canada
E-Flora Electronic Atlas of the Plants of British Columbia
USDA, NRCS. 2010. The PLANTS Database
Image credits:
Scouler’s Corydalis: Pfly Flickr
Pink Corydalis: D Gordon & E. Robertson
Habitat: Pamela Zevit
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Draft 2010
Disclaimer: This species account and related conservation recommendations are draft only and presently under review and subject to change.