Rare Forest Plants of Southern British Columbia
Biological limitations, habitat alteration, and a lack of formal protection have put these plant species at risk.
Ministry of Environment, Lands and Parks “grass” – refers to the showy flowers insects – cimex means “bug” and fugare of nearly all species of that genus. means “to repel.” The species name The species name, lyallii, honours elata means “tall.” Tall bugbane grows David Lyall, a Scottish surgeon and west of the Cascade Mountains from What are they? naturalist who collected in North Oregon to Washington, and north to id you know that in British Colum- America in the mid-1800s. Lyall’s southern British Columbia, where it is bia about a quarter of the flora is mariposa lily grows on the eastern confined to the Chilliwack Valley. considered rare? More than 600 rare front of the Cascade mountains, There, it grows in deciduous and mixed Dplants have been recorded in our from Washington to the South wood forests, mainly composed of province! While these species are impor- Okanagan region, where it is restrict- bigleaf maple, red alder, Douglas-fir tant components of beautiful B.C.’s ed to a height of land between the and western redcedar. Small gaps in the biological diversity, little is known Okanagan and Similkameen valleys. forest canopy resulting from wind- about them. The BC Conservation It flowers in grassy meadows and in throw, fire or the death of older trees, Data Centre, natural openings in Douglas- are important elements of its habitat, as which compiles fir (Pseudotsuga menziesii var. they allow sufficient light to penetrate information Lyall’s glauca) forests. the understorey. Tall bugbane is also on rare species Scouler’s corydalis belongs to found in disturbed habitats, along and plant com- mariposa lily, the fumitory or bleeding-heart road-cuts and in recently logged areas, munities, has tall bugbane family (Fumariaceae). The where plentiful light favours its growth. recently con- Greek name Corydalis refers to However, on these artificially open sites, ducted studies and Scouler’s the refined shape of the flower it is quickly out-competed by species on three rare corydalis are which some say resembles a more adapted to open habitats. forest plants. crested lark. This corydalis is Evidence shows all extremely named after Dr. John Scouler, What do they look like? that under cur- rare in who accompanied botanist yall’s mariposa lily is a 10- to 50-cen- rent conditions David Douglas in his nine- timetre tall plant that each year aris- these species are Canada, and teenth-century explorations of es from a subterranean bulb. It bears at risk, and that are found only the Pacific Northwest. It is La single long, flat basal leaf and up to quick, effective common on the Oregon and twelve delicate star-like white flowers. protection is re- in southern Washington coasts, but The three broad- quired if we British is known only from south- ly lance-shaped Even want to preserve Columbia. western Vancouver Island petals are tinged them as part in British Columbia, though most with a purple cres- of our natural where it is restricted to cent at the base heritage. the Nitinat and Klanawa valleys. populations and conspicuously Lyall’s mariposa lily (Calochortus A shade-tolerant species, Scouler’s occur in fringed with slen- lyallii), tall bugbane (Cimicifuga corydalis can grow over extensive der hairs. The three elata) and Scouler’s corydalis (Cory- areas in cool, moist habitats asso- areas under sepals, slightly dalis scouleri) are all extremely rare in ciated with watercourses and exploitation, smaller that the Canada, found only in southern flood plains, chiefly in mixed petals, display the British Columbia. A combination of forests dominated by bigleaf none of these same purple pat- biological limitations, habitat alter- maple (Acer macrophyllum),red rare species is tern but lack any ation, and a lack of formal protection alder (Alnus rubra), western red- fringed margin. puts these plant species at risk. cedar (Thuja plicata) or Sitka protected The fruit is an Lyall’s mariposa lily is an attractive spruce (Picea sitchensis). in British erect three-winged and delicate member of the lily family Tall bugbane is a member of capsule, ready to (Liliaceae), also known as butterfly lily the buttercup family (Ranuncu- Columbia. release straw- and star tulip. The generic name Calo- laceae). Both its common name coloured seeds in chortus – from the Greek kalo mean- and its botanical genus name, Cimi- July. Two larger mariposa lilies are also ing “beautiful” and chortus meaning cifuga, allude to its ability to ward off found in the Okanagan grasslands and fruit is an egg-shaped capsule which No other species of bugbane is found springs open when jarred even slightly, in British Columbia; our rare species, scattering black, shiny seeds a consider- however, can be confused with a ’ able distance. Only one of the three closely related species, baneberry – other species of corydalis found in B.C. (Actaea rubra), which has similar is found in Scouler’s corydalis habitat. growth habits and leaf Pink corydalis (Corydalis semper- shape. They can easi- virens), however, has smaller flowers ly be told apart by with yellow tips. In the forest under- their flower and
storey, the large dissected leaves of 2 mm1 Scouler’s corydalis can make up a lush foliage, over which twinkle – clusters of pink flowers. Tall bugbane is a rather large plant, 1 to 2 metres tall, and bears 1 cm broad compound leaves that 1 cm look like 3 clusters of maple- like leaves. Its inflorescence 5 mm is made of 50 to 900 tiny white flowers and resembles a bottle-brush. Because these can easily be flowers lack any petals and told apart from their sepals readily fall off, they our rare species soon consist of only the repro- by a close look at the ductive organs, most noticeably flowers. Whereas the sagebrush mari- a starburst of white stamens. When posa lily (Calochortus macrocarpus) has the fruits are dry they split on one side fruit. Baneberry has larger flowers lavender petals, the three-spot mariposa to release small, dark-coloured seeds. arranged in a rounded cluster rather lily (Calochortus apiculatus) has white than in a bottle-brush style, and bears petals that lack the moon-shaped pur- red or white berries. Although the ple pattern characteristic of our species. flowers lack showy petals, the crowd- Often covering large areas, mariposa ed inflorescence of tall bugbane is a lily populations subtly contribute to cheering sight in the shady woods. the beauty of the local landscape. Scouler’s corydalis is a What is their status? 60- to 120-cm tall plant he historical increase or decline of that grows from thick populations of these species is rhizomes (creeping under- unknown, and all that can be cur- ground stems) and bears Trently assessed is their sparse abun- large spreading leaves, each dance and vulnerability to habitat one dissected into many change. Even though most populations lance-shaped leaflets. The occur in areas under exploitation, inflorescence is made of 15 none of these rare species is protected to 20 small, rosy-pink showy in British Columbia. flowers, growing in a spike-like Lyall’s mariposa lily is known from cluster. Each flower is bilaterally only 11 sites in the province. It is symmetrical with four petals. ’ – found on Crown land licensed for One of these is hooded or both grazing and timber harvesting. spurred and the two lower ones Whereas regulations exist that limit are fused to form a lip. The 1 cm the intensity and timing of grazing on Crown land, no specific legislation preserved through the implementa- Distribution of Rare Forest Plants in British Columbia protects this species. It is considered tion of Wildlife Habitat Area and threatened in British Columbia and buffer zones. These protection mea- is Red-listed by the Conservation sures could secure the viability of Data Centre (CDC). existing populations. Scouler’s corydalis has been reported from 18 sites in British Why are they at risk? Columbia and mainly grows on ecause Lyall’s mariposa lily, tall bug- Crown land administered for tim- bane, and Scouler’s corydalis show ber. Its future largely depends on a poor ability to propagate and sound forestry management. The establish themselves in new sites, B Corydalis scouleri species is Blue-listed, or vulnerable, they rely entirely on the preservation of Cimicifuga elata in British Columbia. existing habitats. Today, they are at risk Calochortus lyallii Until recently, tall bugbane was because their habitats are in jeopardy. thought to be extirpated (no longer Extensive logging operations in the establishment of deciduous trees and occurring) in Canada, since the last Nitinat and Klanawa valleys pose the the creation of natural canopy gaps in record of this plant in British greatest threat to existing populations second growth stands, both important Columbia dated from 1957. of Scouler’s cory- components of Scouler’s corydalis and The species was rediscovered dalis. Modifica- tall bugbane habitats. in 1996 and field work Trends in tion and destruc- Depletion of the genetic pool is also recently conducted by the rare species tion of habitat a foreseeable threat for these species, CDC confirmed its presence due to logging because of poor gene flow between in eight sites. Half of the populations threaten tall bug- Canadian and American populations. known sites in B.C. occur in may be bane populations The consequences of low genetic disturbed areas such as log- in the Chilliwack diversity can include low resistance to ging roads and clearcuts, valuable Valley. In the disease, limited ability to adapt to a where the species is not likely indicators of South Okanagan, changing environment, and poor to persist. Tall bugbane is decline of peri- capacity to colonize new sites. All can rare throughout its range. It significant odic natural fires, severely impact a species in the long is considered vulnerable to environmental trampling by live- run. For the tall bugbane, poor genetic extirpation or extinction in stock, and increas- diversity is already an issue. Because its Washington, and is a candi- changes. ing encroach- flowers lack nectar, it is a poor com- date for listing as a “threat- ment by exotic petitor for pollinators and has adapted ened or endangered species” in species, all contribute to degrade the by allowing fertilization to occur in the Oregon. In British Columbia it is habitat of Lyall’s mariposa lily. same inflorescence, which reduces the considered endangered, and is on These rare species all depend on mixing of genes. Its relatively small the Red List. Two protected areas relatively young forests. Under nor- Canadian populations – ranging in designated by the BC Ministry of mal circumstances, young forests are size from 1 to 67 individuals – further Forests as a “wildlife tree patch” and replaced by mature and old forests, compound the problem. a “visual landscape unit” are forms but natural disturbances constantly of protection this species currently rejuvenate forest stands, providing Why are they important? receives in Canada. suitable habitat for many species. In he preservation of rare species is Although no current legislation modern times, human intervention vital to the conservation of bio- protects these three species, tall bug- has steadily reduced the frequency of logical diversity in British Colum- bane, Scouler’s corydalis and Lyall’s these crucial natural disturbances. Tbia. Losing rare plants will add to mariposa lily are candidates for Forest fires, critical for the survival of the impoverishment of our ecosys- listing as “Identified Wildlife” – Lyall’s mariposa lily, are now much less tems, already under severe stress in species sensitive to habitat alter- frequent due to stand management many places. Although we do not ations associated with forest or range practices. Likewise, current silvicul- fully understand the dynamic rela- practices. Critical habitats will be tural practices tend to prevent the tionships between species, we can be sure that all species contribute to the Occurring at the northern range As individuals, we should become richness and the complex balance of of the species, Canadian populations aware of the diversity of life around the ecosystem they inhabit. For exam- of Lyall’s mariposa lily, Scouler’s cory- us, and learn to appreciate it. See what ple, Lyall’s mariposa lily is a you find in the woods or in good source of food for a the fields near your home. variety of invertebrates and Use field guides available vertebrates that browse on its for your region to identi- herbage, fruits and bulb. fy a bird or a flower. Join Trends in rare species or support local natu- populations may be valu- ralist organizations that able indicators of signifi- promote education about cant environmental changes. and conservation of these Lyall’s mariposa lily’s habi- rare organisms. The South tat is an area of high bio- Okanagan Conservation logical diversity threatened Strategy coordinates re- by human-induced distur- search and inventory in bances. Monitoring of its that region. The Federa- populations could provide tion of BC Naturalists and valuable information for ’ the Okanagan-Similka- the management of large , meen Parks Society are . areas of our Douglas-fir involved in habitat conser- Samantha Flynn photo forest-grassland complex. vation. Supporting land In the same way, sensible management dalis and tall bugbane, could play a acquisition by government and private of Scouler’s corydalis populations crucial role as centres for expansion agencies, such as The Nature Trust found in the rare Sitka spruce/ and migration in the event of global of B.C. and The Nature Conservancy Salmonberry (Picea sitchensis/Rubus warming. Peripheral populations some- of Canada, is an effective way to help spectabilis) community would likely times differ slightly from central protect our natural heritage. help preserve this unique habitat. ones, and can therefore add to the Preserving species’ adaptability to environ- potential medic- mental changes. inal properties of Losing rare Finally, any ecological and plants is another plants will genetic studies of these rare reason for the species would considerably conservation of add to the improve our understanding of all biodiversity. impoverishment species rarity, enhancing our Tall bugbane is competence in preserving bio- chemically very of our logical diversity. similar to a close- ecosystems, ly related species, What can we do? black cohosh already under inding out more about our (Cimicifuga race- severe stress in rare species is vital for the mosa), which is preservation of B.C.’s bio- commonly used many places. Fdiversity. What makes these in Eastern Asia plants rare? Where are they found? and the U.S. Appalachian region Are their numbers going down sig- for its medicinal properties. The nificantly with time? General and two species have anti-inflammatory detailed field surveys are required to and sedative properties, and other answer these questions and gather ’ medicinal uses for tall bugbane might other information needed to implement . one day be revealed. appropriate conservation strategies. Photo: Gerry Allen Preserving existing populations of Lyall’s mariposa lily, tall bugbane, and Scouler’s corydalis is the only way to ensure their survival. Land acquisition for the creation of parks and reserves, along with the implementation of protected areas will secure some of these populations. Sound forest management that maintains and mimics natural dis- turbances will support these species and overall biological diversity. Thin- ning stands by removing a few large trees, and burning of small patches in Douglas-fir forests, are management tools that favour tall bugbane and Lyall’s mariposa lily populations. Respon- sible logging practices that preserve margins along water courses should
- , . . Lois Kemp photo Lois Kemp photo spare most of our known Scouler’s and value the diversity of life enough corydalis populations. to take action, there is a chance that Solutions are available and protec- these species will remain a part of our tion is possible. As long as we care Canadian legacy.
, : BC Conservation Data Centre Ministry of Environment, Lands and Parks ’ PO Box 9344 Stn Prov Govt . Victoria, British Columbia V8W 9M1 Steve Cannings photo www.elp.gov.bc.ca/wld/cdc
, : Habitat Conservation Trust Fund PO Box 9354 Stn Prov Govt Victoria, British Columbia V8W 9M1 www.elp.gov.bc.ca/hctf
Forest Renewal British Columbia
--- . ’ , . Mike Miller photo Printed in British Columbia on recycled paper with vegetable inks Q.P.4500015472