Mapping Species Distributions


Sidalcea hendersonii, photo by Frank Lomer.

Frank Lomer
Honorary Research Associate, UBC Herbarium

Reprinted from Botanical Electronic News #432, 433, 435, 437, 438 (January, March, May, June 2011), with permission. Note that rare plants listed here are red and blue-listed vascular species as defined by the Conservation Data Centre of British Columbia.


The Fraser River is British Columbia's major river system; it flows entirely within BC, draining nearly 25% of the province. The headwaters lie in the Rocky Mountains near Mt Robson and included in its drainage basin are such major rivers as the Nechako, Chilcotin, Thompson and Pitt. It cuts through the Coast Mountains in the Fraser Canyon in a speedy fashion from Lytton to Hope, where it slows, flattens, and slightly meanders in a more or less straight line through the Fraser Valley to empty into the Pacific Ocean at the Strait of Georgia between Vancouver Island and the Mainland. Virtually all of the water comes from sources within BC, save a small portion of the Sumas and Chilliwack drainages which originate in Washington State. There are no dams on the Fraser and relatively little heavy industry on its shores. Urban and industrial expansion along the lowland shores are the major threats to its well-being.

The Fraser Valley is a fertile floodplain that stretches about 150 km from Hope to Vancouver, hemmed in by mountains to the north and most of the South to near Sumas. The United States forms the border from Sumas to Surrey and White Rock. The river shore is botanically interesting as the Fraser makes its way from the end of the canyon where rapid flowing water deposits coarse rock, gravel and sand to form islands and shores that dry to drought conditions by summer's end when the high waters have receded. Here can be found plant species that get washed down the river from their usual home in the dry interior: Apocynum cannabinum L., Clematis ligusticifolia Nutt. var. ligusticifolia, Gaillardia aristata Pursh, Sporobolus cryptandrus (Torr.) A. Gray, Toxicodendron rydbergii (Small ex Rydb.) Greene, and others. Even the occasional Pinus ponderosa C. Lawson and Juniperus scopulorum Sarg. can be found on a few islands. These sprout up from cones that get washed down the river in flood times, rarely making it to medium-sized trees. But everything eventually gets washed away over time by the relentless scouring of spring runoff which peaks in June. Extensive dyking and channelling in the Fraser Valley limit the natural late spring floods.

Thyme-leaved spurge (Chamaesyce serpyllifolia ssp. serpyllifolia), photo by Adolf Ceska.

Further downstream in the central valley near Chilliwack, the waters slow and finer materials accumulate to form sandy bars and shores. The scouring is less intense and more stable plant communities are maintained. The dominant species here are Alnus rubra Bong., Betula papyrifera Marsh., Cornus stolonifera Michx., Populus balsamifera subsp. trichocarpa (Torr. & A. Gray ex Hook.) Brayshaw and Salix sessilifolia Nutt. The receded shorelines are sandy washes with rounded stones which are stabilized with perennials dominated by Artemisia lindleyana Besser, Elymus canadensis L., Gaillardia aristata Pursh, Symphyotrichum subspicatum (Nees) G.L. Nesom, and Phalaris arundinacea L.

Past Chilliwack towards Langley and the confluence with the Pitt River in Pitt Meadows and Coquitlam, the waters slow further, even to the point of going in reverse with the tidal influence of the sea. The substrate becomes primarily mud and fine sand and the vegetation changes to marshy shores and inundated mud flats. This habitat is among the most botanically interesting to be found in BC and supports many rare species.

Finally, at the very end, the waters are calmed to a standstill at times and the shoreline is a thickly matted mass of tidal marshland vegetation that slowly shifts to salt-influenced estuarine species such as Bolboschoenus maritimus var. paludosus (A. Nelson) Dorn, Carex lyngbyei subsp. cryptocarpa, Schoenoplectus pungens var. longispicatus (Vahl) Palla, and Triglochin maritima L. The Fraser delta is a rich and important wetland, especially for migratory waterfowl, but it also lies in the southern suburbs of Greater Vancouver, so the natural landscape is being slowly destroyed little by little. The entire Fraser Valley is undergoing relentless urbanization that shows no signs of stopping.

Heterocodon (Heterocodon rariflorum), photo by Hans Roemer.

Surveying the Fraser Valley

The British Columbia Conservation Data Centre, BC Ministry of Environment, initiated a survey of the rare vascular plants of the Fraser Valley during the summer of 2008. In 2009 and 2010 I made many more trips in my kayak to continue to search for rare plants. The following is a list of all the known rare vascular plant species in the Fraser Valley in the lowland zone up to approximately 200 m elevation. Included are four species [Bidens vulgata Greene, Chamaesyce serpyllifolia (Pers.) Small ssp. serpyllifolia, Eleocharis ovata (Roth) Roem. & Schult., and Heterocodon rariflorum Nutt.] new to the Fraser Valley discovered during this survey.


Acorus americanus (Raf.) Raf. - Acoraceae

Rare and widespread in the BC interior, very rare in the Fraser Valley.  Sweetflag has been collected from two wetland sites in Pitt Meadows, but has not been reported since 1973 (UBC: V.C. Brink s.n., T. Barnard 107).  Recent search efforts in the Pitt River area over the past fifteen years have revealed nothing until 2009 when a dense stand was rediscovered at the site where Vernon Brink collected it near South Gilley Slough, Pitt Meadows (UBC: Lomer 7083). The introduced Acorus calamus from Europe may also occur in the Fraser Valley.  It can be told from the native species by its sterility; it cannot produce ripe fruit, whereas the native can.  

Anagallis minima (L.) Krause - Primulaceae

This diminutive annual had not been collected in the Fraser Valley prior to about 1999.  Since that time it has been discovered at 8 sites in the Greater Vancouver area (UBC: Lomer 5668).  All sites were man-made habitats and I believe that this species is a recent introduction here.  It has been found in cranberry bogs, sand dredgings, disturbed peaty road clearings, gravelly roadside depressions, cleared moist gravel flats, old gravel pits, and wet field pools.  It appears to be spreading.

Anemone virginiana L. - Ranunculaceae  

One of the most remarkable species to occur in the Fraser Valley.  This Anemone was collected by John Macoun from "woods" near Agassiz in 1889 (CAN: Macoun 931).  I had assumed it was extinct long ago, if there was not a label mix-up, but in 2010 a very small patch of Anemone virginiana was discovered in an alluvial meadow on an island in the Fraser southwest of Agassiz.  Macoun's collection was identified as A. virginiana L. var. riparia (Fern.) B. Boivin [syn. A. virginiana L. var. alba (Oakes) A.W. Wood] in Flora North America, Vol 3.  The rare native that grows further north in BC is A. virginiana L. var. cylindroidea B. Boivin.  According to Flora North America, variety alba grows in riparian areas, but is restricted to eastern North America.  Otherwise the distinctions are slight and I cannot tell if the plants are var. alba or var. cylindroidea.  If they are var. alba I would assume it is introduced and has persisted (barely) in the Agassiz area for more than 100 years.  On the other hand, var. cylindroidea is known near the Fraser at Prince George, so it is possible that it naturally washed down the river long ago to establish itself in sandy openings on river islands and spread in a small way.          
Berula erecta (Huds.) Coville - Apiaceae

Local in the Okanagan, very rare in the Fraser Valley.  This semi-aquatic perennial was collected near Popkum in 1938 (UBC: Glendenning s.n.) and thought to be extinct in the Fraser Valley.  It was rediscovered in the Fraser Valley near Cultus Lake by Jamie Fenneman in 2008.  It is abundant and dominant in a beaver dam complex on Department of National Defence land (UBC: Lomer 6756).  For such a dominant population (at this site), it is surprising that it is not found elsewhere in suitable habitat.  So far no other sites have been discovered, despite several searches in suitable habitat nearby, as well as west to Sumas Mt. and east to Hope.
Bidens amplissima Greene - Asteraceae

This confounding and variable species is present in the Fraser Valley from Delta to Chilliwack. The Fraser delta contains plants that are morphologically confusing. These are rather tall slender estuary plants with long petioles and long achenes bearing long awns (UBC: Lomer 6765). It appears that the slender habit is largely an environmental response to constant tidal inundation, while the long fruit, over 2 cm long, is genetic. Dozens of fruits were collected from Fraser estuary plants in Richmond and the longest fruit bodies averaged 13 mm and the awns averaged 8.5 mm. The longest fruit body was 17 mm and the longest awn 10 mm. These fruit traits held when plants I collected were grown under garden conditions in my front yard. These Fraser estuary plants with the long fruit appear to be a unique form of {i}Bidens amplissima{/i}. Genetic testing is needed to confirm their true identity. If we take these estuary plants into account as part of the variation within the species, then {i}Bidens amplissima{/i} may be more widespread than reports indicate. These estuary forms can be found north to the Kimsquit River near Bella Coola (V: C. Clement 8327) and, perhaps, south to the Columbia. Further collecting is needed to confirm the species' full range. Bidens amplissima has recently been collected at several new sites in the Fraser Valley.  It occasionally pops up as a waif along roadsides, in soil dumps and in agricultural fields, presumably spread by animals onto which the ripe fruits readily cling.  Late season plants with limited growing time are mostly small, rayless and often lack any indentation on the leaf margins.  This variability makes for a difficult species to identify.
Bidens vulgata Greene - Asteraceae

Despite the name, this species is very rare and not weedy in BC.  It was found for the first time in the Fraser Valley during the CDC survey in 2008.  A relatively small population was discovered in a ploughed field below Sumas Mountain (UBC: Lomer 6829) growing with Bidens amplissima Greene, Bidens cernua L. and Bidens tripartita L.  I assume this population was introduced unintentionally as part of waterfowl enhancement plantings, so the origin may be from outside the province.  Not observed in the natural wetlands nearby and not expected at other sites in the Fraser Valley, except perhaps as an introduction.  It can be told from the common Bidens frondosa L. by its more numerous flower head bracts, yellower disc flowers, wider fruit and sturdier habit. 
Callitriche heterophylla Pursh var. heterophylla - Callitrichaceae

The species as a whole is common, but the variety heterophylla is not often collected in BC.  Records exist from the Vancouver area, including Coquitlam (UBC: Lomer 90-7), Surrey (UBC: Lomer 91-125A) and Pitt Lake (V: Brayshaw 78-794B) so it should be expected in more wetland sites in the Fraser Valley.  The small fruit, less than 1 mm, mark the variety.  So it is not surprising there are few records.

Vancouver Island beggarticks (Bidens amplissima). Photo by Ryan Batten.

Caltha palustris L. var. palustris - Ranunculaceae

This attractive, early-flowering marsh plant is very local along the tidal shores of the Fraser River in bare muddy sites (UBC: Lomer 91-32).  Known from approximately 26 sites along the north and south arms of the Fraser in Richmond.  Elsewhere in BC few sites are known, and always in estuaries or tidal influenced waters.  The rivershores which it inhabits are generally under threat from shoreline dyking and development.  Marsh marigold is a popular garden plant and it has been observed as an escape from cultivation.  These plants are virtually identical to our native populations, but usually the escaped plants are more floriferous and compact and grow away from tidal marshes, usually in parks and urban sites where they look somewhat out of place compared to the native vegetation.  
Cardamine parviflora L. var. arenicola (Britton) O.E. Schulz - Brassicaceae
An easily overlooked annual that is rarely observed in BC. It is rather difficult to identify due to a similarity with other common Cardamine species.  It is a little different because it has very narrow leaflets throughout and often grows on drier sites than the other bittercresses.  Known in the Fraser Valley only from a very small population in Port Coquitlam (UBC: Lomer 91-58) that may be extirpated.  Its native status in the Fraser Valley is uncertain, in my opinion.  Elsewhere it is known in BC only from an old collectioins from Nanaimo and perhaps Goldstream (specimen not verified).
Carex amplifolia Boott - Cyperaceae

This attractive broad-leaved sedge is very local in the Fraser Valley, but rather widespread elsewhere in BC and further collecting will likely prove it is not rare in BC.  It is most commonly found in the Burnaby Lake area south to the Fraser River, with an outlier population near UBC (UBC: Krajina s.n.).  Elsewhere it is known in the Fraser Valley from Clayburn, Maple Ridge and Pitt Meadows.  It can be expected in boggy seeps, wet ditches and and other wet sites that are not too saturated year round.

Carex comosa Boott - Cyperaceae

Local in the Okanagan, rare elsewhere.  Old collections from the Fraser Valley from 1912 (UBC: Henry s.n.) up to 1978. Surprisingly, it was discovered at three new sites in the Fraser Valley in 2008, after going un-noticed for a period of several years.  It is well adapted to disturbed marshy shores and should be secure in the protected areas it has been found in: Cheam Wetlands Regional Park (UBC: T. Taylor 116), Burnaby Lake (UBC: Lomer 7065), Sumas Mt waterfowl habitat on private property.  Also found in 2010 in a railroad ditch west of Agassiz and a wetland east of Agassiz.  I suspect that, though native in the Fraser Valley, it has also been introduced as part of waterfowl enhancement plantings. 

Carex hystericina Muhl. ex Willd. - Cyperaceae

Collected from dredged sand in Coquitlam, east of Vancouver (UBC: Lomer 98-183), but this was an impermanent site from preload dumpings prior to building construction.  The seed must have been washed down the river from sites in the interior where this rare species is known from the Fraser drainage, among other places.  In 2010 a single plant was observed along a sandy meadow shore on an island southwest of Agassiz.  So it appears this species can arise naturally from seeds brought down the Fraser River originating from interior plants.   
Carex interrupta Boeck. - Cyperaceae

Until about 1996 this species was rarely collected or seen in BC.  In subsequent years it has proven to be an abundant species, but one of rather restricted habitat in the Fraser Valley. It grows primarily along the eroding firm mud banks of the Fraser River and proximal tributaries from Hope to Surrey (UBC: Lomer 97-36).  Rarely elsewhere such as a boggy ditch in Richmond near the Fraser (UBC: Lomer 96-20).  Still rather rare overall and somewhat threatened by habitat destruction, especially dyking for riverside development.  It looks somewhat like Carex lenticularis Michx., except that it is rhizomatous and grows in dense colonies, the lowest spikelet is often remotely flowered in the proximal portion (interrupted) and the perigynium is smaller.
Carex scoparia Schkuhr ex Willd. var. scoparia - Cyperaceae

This sedge is most abundant in BC in the Fraser Valley.  It grows in wet sites that may dry out by summer's end or remain wet year round.  It does well in disturbed man-made habitats such as wet fields, hydro line right-of-ways, roadside ditches, and boggy clearings.  It can be recognized best by its leafy, clumped habit and compact to somewhat loosely arranged, often nodding, heads of pointed spikelets. It has been recorded from 30 sites in Greater Vancouver, mainly in the Burnaby-Coquitlam-Surrey area (UBC: Lomer 96-190) and is also locally frequent east to Chilliwack.     
Carex vulpinoidea Michx. - Cyperaceae

This densely leafy sedge is occasionally encountered in low wet sites from  Vancouver to Chilliwack.  Recorded from 8 sites in Greater Vancouver, it is most frequent between Abbotsford and Chilliwack (UBC: Faris 142).  It does well in wet grassy clearings such as ditchbanks and road verges, is somewhat adapted to disturbance, and is not really threatened by development unless there is wholesale removal of the natural vegetation. 

Phantom Orchid (Cephalanthera austiniae). Photo by Kevin De Boer.

Cephalanthera austiniae (A. Gray) Heller - Orchidaceae

This ghostly myco-heterotrophic species is more a plant of forested hillsides than the Fraser River lowlands covered here.  It occurs on both sides of the Fraser on lower slopes, but is extremely rare here and apparently does not flower every year, so it may remain dormant for long periods. (UBC: Kennedy 5079). 
Ceratophyllum echinatum A. Gray - Ceratophyllaceae

An aquatic plant much like the common C. demersum, but more slender.  It tends to grow in clearer, more acidic bog water than the latter species.  It has been found at Devil's Lake, west of Hope (Ceska 1978, unpublished), and I expect that further collecting will prove that this species is not rare in southwest BC, though there appear to be very few sites in the Fraser Valley.
Chamaesyce serpyllifolia (Pers.) Small subsp. serpyllifolia - Euphorbiaceae

A rare prostrate annual that grows along sandy receded pools, pond and lake margins in southwest and south-central BC; not dry sites as reported in most literature.  Though the sites may by dry when the plants are mature, this species seems to require saturation during dormancy unlike the similar and common Chamaesyce glyptosperma (Engelm.) Small, which is a weedy species often found along roadsides.  In BC C., C. serpyllifolia subsp. serpyllifolia is known from a few lakeshores on Vancouver Island, the Thompson River from Spence's Bridge to Kamloops, Shuswap Lake, and the Okanagan from Osoyoos north to Vaseux Lake.  It was found for the first time in the Fraser Valley during the CDC survey in south Langley along a sandy receded lakeshore that was once a gravel pit (UBC: Lomer 6887).  About 40 plants were growing with Corrigiola litoralis L., Anagallis minima (L.) Krause, Lindernia dubia (L.) Pennell var. anagallidea (Michx.) Cooperr., and Plagiobothrys scouleri (Hook. & Arn.) I.M. Johnst.  In 2010 more than 100 plants were observed at the same site. 
Clarkia amoena (Lehm.) A. Nels. & Macbr. var. caurina (Abrams) C.L. Hitchc. - Onagraceae

There is a small population of this attractive annual species growing on south-facing rocky knolls on Sumas Mountain (UBC: Lomer 4433).  It is more common on the Gulf Islands and southern Vancouver Island, but it could be expected from other south-facing rocky bluffs in the Fraser Valley.  It is not known elsewhere on the BC mainland.  
Claytonia washingtoniana (Suksd.) Suksd. - Portulacaceae

A species derived from hybridization of two common species: Claytonia perfoliata Donn ex Willd. and C. sibirica L.  It grows on mossy rock outcrops on the north side of the Fraser from Horseshoe Bay east to Pitt Meadows (UBC: Lomer 3949), and perhaps can be found in similar sites east of the Pitt River.  It is early flowering, from March to May, and typically grows on low diversity mossy sites that dry out completely by the end of spring.

Mossgrass (Coleanthus subtilis). Photo by Curtis Bjork.

Coleanthus subtilis (Tratt.) Seidel - Poaceae

Coleanthus subtilis has a very fragmented area of distribution. It is rare in central Europe, with historical records in Russia and Austria (Hejny 1969, Woike 1999). It was recently discovered in southern Poland (Fabiszewski & Cebrat 2003). In Asia it has been recorded in the Ob River watershed (Taran 1994) and in the Amur River floodplain (Nechajev & Nechajev 1972, 1973). In North America this species was first collected by T.J. Howell on Sauvie Island near Portland, OR in 1880 and later along the Columbia River from Bingen, WA to Portland, OR by W. Suksdorf and others from 1883 to 1927. In British Columbia it was first spotted by O. & A. Ceska at Shuswap Lake in September 1989 and a few days later collected by M.E. Martin on Sept. 18, 1989 (V: Martin, s.n.). The same year, A. & O. Ceska collected it again on Sauvie Island, OR (V: A. & O. Ceska 26885) and on Hatzic Lake in the Lower Fraser Valley (V: A. & O. Ceska 26868) - see also Ceska (1995). At the BOTANY BC 2002 in Castlegar, O. Ceska spotted two plants of Coleanthus subtilis at the exposed bottom of Lower Arrow Lake near Syringa Creek Provincial Park (A. Ceska, personal communication).

The North American botanists were puzzled by the occurrence of this species in North America and either considered it introduced (Hitchcock et al. 1969: 539) or were confused about its native status there (Flora of North America vol. 24: 618). Recently, Catling (2009) reported Coleanthus subtilis from the Northwest Territories and concluded that it should be considered "native at all of its North American sites" and gave several valid arguments for this thesis: 1) its restricted and unusual habitat; 2) global rarity; 3) suffusive rarity, which has sometimes been mistaken for introduction; 4) occurrence in botanically rich regions and close association with rare native species; 5) relatively early [or late] year of collection; 6) distribution corresponding to well recognized native pattern; 7) lack of evidence of spread to anthropogenic habitats; and 8) the fact that it is easily overlooked by early collectors because it appears at intervals of several years only when water levels have dropped sufficiently. (Prepared with contributions by Adolf Ceska).

Crassula aquatica (L.) Schoenl. - Crassulaceae

A local plant of muddy sites usually along major rivers in BC such as the Columbia, Fraser, Harrison, Pitt and Pend d'Oreille. It is abundant and co-dominant in tidal mudflats along the lower Fraser from Steveston to Langley and along the Pitt River to Pitt Lake, as well as east to Harrison Lake (UBC: Straley 6267).  It is widespread in southern BC from Vancouver Island to the Rocky Mt Trench.  Now known from enough sites that it was recommended for removal from the BC rare plant tracking list.
Cuscuta campestris Yunck. - Cuscutaceae

This parasitic species looks like a tangle of orange string and can grow on a variety of hosts including cultivated plants.  Any Cuscuta growing away from the seashore in the Fraser Valley would likely be this species or else an introduced species of dodders.  Though it is rather rare in BC, it is perhaps not deserving of protective status because of its weedy nature that allows it to pop up any time it has a fortuitous chance to get a stranglehold.  It has been found in the Vancouver area growing on potato plants in a garden and basil in a greenhouse (UBC: Lomer 6701).  In the Fraser Valley, it has not yet been found outside of Greater Vancouver.



Elatine rubella Rydb. - Elatinaceae

A small prostrate annual of wet muddy sites, often half buried. It grows in the wettest depression pools on tidal mudflats and flood pools along the Fraser, Pitt and Harrison Rivers. 14 sites are known in Greater Vancouver, all along the riverflats, except for one site on the shore of Latimer Lake in Surrey, where it is very scarce and was not found in recent years. It will rarely show up from time to time in Fraser River sand dredgings used as preload in preparation for building construction (UBC: Lomer 97-604).

Eleocharis ovata (Roth) Roem. & Schult. - Cyperaceae

A small annual spike-rush that was known for certain in BC only from Ellison Lake in the Okanagan. During the 2008 CDC survey, a population of over 1000 plants was found on the east shore of Hatzic Lake (UBC: Lomer 6867) and found again on the muddy receded shore of Latimer Lake, Surrey (UBC: Lomer 6883).

At Hatzic it was growing on emergent mudflats with Limosella aquatica L., Eleocharis acicularis (L.) Roem. & Schult., and Crassula aquatica (L.) Schoenl. It looks much like the common annual spike-rush in the Fraser Valley -Eleocharis obtusa (Willd.) Schult., but the tubercles on the achene tops are narrower and more triangular in outline. The stems are mostly down-curved and are of variable lengths giving the plants a low starburst-like appearance. The Latimer Lake population numbers about 500 plants in the muddiest sites and though these plants were observed in previous years they were assumed to be E. obtusa , so it is quite likely that more sites will be found in the Fraser Valley and indeed in southern British Columbia once this species becomes better known.

Eleocharis parvula (Roem. & Schult.) Link ex Bluff, Nees & Schauer - Cyperaceae

A diminutive perennial with bulb-like basal tubers, restricted to brackish seashores and estuaries in BC. Known in Greater Vancouver from the head of Burrard Inlet, the Serpentine estuary, Little Campbell River estuary and Iona Island (UBC: Lomer 97-596). It does not grow in freshwater sites in The Fraser Valley. I expect that a thorough search of coastal estuaries in brackish sites, where the tidal shore is exposed compacted mud, will reveal that this species is not of conservation concern in BC.

Fox Sedge (Carex vulpinoidea). Photo by Ryan Batten.

Elodea nuttallii (Planch.) H. St. John - Hydrocharitaceae

An aquatic plant mostly of shallow water along the major rivers. It looks like the common Elodea canadensis, but the leaves are narrower and toothed along the upper margins and the male flowers are sessile and break free from the leaf axils and float to the surface for pollination. Known from 12 sites in Greater Vancouver, all along the Fraser and Pitt Rivers (UBC: Lomer 97-584). It is to be expected in other sites up the valley and will likely be removed from the rare plant list eventually because it is widespread in BC and often overlooked. It can survive in polluted water and has been introduced to places far outside its native range.

Epipactis gigantea Dougl. ex Hook. - Orchidaceae

This robust orchid of wet, often calcareous sites, was known in the Fraser Valley from Cultus Lake where it was collected more than 70 years ago (UBC: H.H. Rose s.n.). It was rediscovered there in 2004 (UBC: Lomer 5404). It is quite frequent along the northern lakeshore for 100 meters. It is not yet threatened on this undeveloped side of Cultus Lake, though the near-constant summertime wave action caused by boaters is battering the shoreline plants. In 2009 a large population of E. gigantea was dscovered by Monica Pearson in a wetland east of Agassiz. As well, a few small patches exist on the Fraser River islands southwest of Agassiz. Surprisingly, these plants are not in wet sites in summer, but are moistened or even inundated during high runoff.

Eutrochium maculatum (L.) E. E. Lamont var. bruneri (A. Gray) E. E. Lamont - Asteraceae

For years it was believed that this outstanding perennial (Joe Pye weed) was merely an introduction from eastern North America where it is quite common. It was collected several times from 1897 to 1926 in the Vancouver area (UBC: Henry s.n.), in the 1940's in Huntingdon, and up to as late as 1955 near Chilliwack. It was assumed, over time, it had died away. But evidence suggests that this taxon is a very rare native that is barely hanging on in the Fraser Valley.

Variety bruneri is the western component of a species that is of sporadic and rare occurrence at the westernmost portion of its range. It is believed to be extinct from Washington (Whatcom Co.). A small population existed near Steveston in the Fraser delta, but that disappeared by natural causes by about 2000. In 2007, Eutrochium maculatum var. bruneri was rediscovered on Kirkland Island about 4 km E of the Steveston site (UBC: Lomer 6318).

This population seems more secure with about 126 flowering stems counted and is not endangered by any development threats, though it is still a small population that could succumb to disease or eventual crowding by Phalaris arrundinacea L. and Lythrum salicaria L.. It seems to be a very poor reproducer from seed; just one juvenile plant was observed away from the main population. The Huntingdon site is apparently lost to development. The Chilliwack site is from 6 1/2 miles east of town. This would be about Rosedale. There is a slough with potential habitat in the area, but no plants have been observed during more than 10 years of cursory searching.

It was observed in Ladner Marsh in the late 1960's (Terry Taylor, personal communication), but it has not been found again, though the habitat is vast. In 2009 a second site was discovered by Monica Pearson in a wetland east of Agassiz in the Fraser Valley. The only other known site for E. maculatum var. bruneri in British Columbia is in a wetland southwest of Revelstoke, discovered by Curtis Bjork (UBC: Lomer 7113).

Glyceria leptostachya Buckley - Poaceae

A perennial grass from wet places in coastal BC. Known in the Fraser Valley from 6 sites in the Vancouver area, east to near Barnston Island, Surrey (UBC: Lomer 93-250). Elsewhere in BC it is widespread on the coast, but rarely encountered from the Queen Charlotte Islands south to Vancouver Island and the Gulf Islands. Generally a microscope is needed to separate it from Glyceria borealis (Nash) Batch., G. fluitans (L.) R. Br., or G. x occidentalis (Piper) J.C. Nelson, all of which occur in the Fraser Valley.

Helenium autumnale L. var. grandiflorum (Nutt.) Torr. & A. Gray - Asteraceae

This is one of the relatively few native BC plants that has found a place in the horticultural trade. Var. grandiflorum is a larger variety with longer ray flowers and more numerous heads, in well-grown plants at least. It is difficult to tell from the common var. montanum which is a variety that grows on river shores along the Thompson and Fraser Rivers as well as several other places in southeast BC. Var. montanum also can be found as a native plant in riverbars of the upper Fraser Valley from Agassiz to Hope and rarely downriver as well, usually in sand dredgings. Var. grandiflorum can be told by its larger flower heads and rays, taller stature and more robust habit.

Var. grandiflorum can be found scattered along a 20 km stretch on both sides of the Pitt River from Douglas Island to Pitt Lake (UBC: Bradfield 92). It was discovered on Westham Island in 2008 and can be expected anywhere along the Fraser River on wet vegetated shores, east to about Hope. There are old collections from ditches in Langley; these sites may or may not have been destroyed. There is a large population in back of the Ruby Creek Rest Stop, Hwy 7, west of Hope.

Mountain Sneezeweed (Helenium autumnale var. grandiflorum). Photo by Hans Roemer.

Heterocodon rariflorum Nutt. - Campanulaceae

A small annual from seepage sites on sunny slopes. A population was discovered 4 km west of Hope in 2008 (UBC: Lomer 6607). To be sought in similar habitats on the lower mountain slopes north of the Fraser River, but it is expected to be very rare here.

Hydrophyllum tenuipes A. Heller - Hydrophyllaceae

A woodland species from moist shaded sites that is occasionally also found in grassy clearings. It can be found in the Abbotsford area (UBC: Pincott 5456). Elsewhere in BC, it is known only from Goldstream and the Sooke River on Vancouver Island. It should be sought along shaded streambanks and ravines in the central valley.

Juncus occidentalis Wiegand - Juncaceae

This native rush was not recognized by most botanists here until recently. It is proving to be quite frequent on southern Vancouver Island and the Gulf Islands. It was not thought to occur in the Fraser Valley aside from a small, presumably introduced, population on a highway bank in Coquitlam. Western rush was found in a field below Sumas Mountain, east of Abbotsford, during the 2008 CDC survey (UBC: Lomer 6840) and it may be expected to occur at other sites in the Fraser Valley. It looks very much like the common Juncus tenuis Willd., but can be recognized by the short, rounded sheath-top auricles. Juncus tenuis auricles are long and pointed. It will likely be removed from the rare list once more collections are made.

Juncus oxymeris Engelm. - Juncaceae

This rush with the flattened blades and multi-branched flower clusters is one of the most noticeable in the BC flora, but is often confused with the common Juncus ensifolius Wikstr. Juncus oxymeris is a more robust plant with a more diffuse inflorescence with more pointed fruit capsules. It is locally common along the tidal shores of the Fraser and Pitt Rivers. It is also known along the tidal shores of the Somass River in Port Alberni on Vancouver Island, but nowhere else in BC as far as I can tell. In BC, this species is not known away from tidal habitats, except as a waif on sand dredgings near these sites. It occurs from near Steveston, throughout the South Arm of the Fraser, sporadically along the North Arm, rarely from Richmond to the Coquitlam River due to lack of habitat, and is dominant for a 20 km stretch on both sides of the Pitt from Douglas Island to Pitt Lake (UBC: T. Taylor, s.n.).

Despite its relative abundance it is still considered a rare plant in BC due to its limited range and the heavy development pressures in the lower Fraser River.

Lilaea scilloides (Poir.) Hauman - Juncaginaceae

A rather succulent annual that is often overlooked because it grows in wet tidal mud in our area and is rather inconspicuous amongst the sparse vegetation. Known from 18 sites in Greater Vancouver along tidal shores of the Fraser and Pitt Rivers (UBC: Henry s.n.). It is also known from Pitt Lake. I would not expect it to occur outside areas of tidal influence in our area. Some sites are threatened by riverside development, while others are secure as part of the tidal wetlands that are not presently under direct development pressures.

Lindernia dubia (L.) Pennell var. anagallidea (Michx.) Cooperr. - Scrophulariaceae

Known from about 30 sites in Greater Vancouver and rarely elsewhere in the Fraser Valley, such as Hatzic Lake and Sumas Mt (UBC: Lomer 6842). Elsewhere in British Columbia, it occurs from the Okanagan north to Kamloops Lake and Shuswap Lake. In the Fraser Valley it grows in a variety of ephemeral habitats: pond and lake shores, tidal river flats and muddy shores, dried pools, field depressions, cranberry fields, mud puddles, dredged sand landfills, etc. and even as a roadside weed in pavement cracks and gaps. It survives in man-made habitats and thus is able to persist under the development pressures in the Lower Mainland, but these populations are prone to disappear over time.

Lupinus rivularis Dougl. ex Lindl. - Fabaceae

This attractive lupine grows in man-made habitats such as dykes, railroad track sides, dredged sand piles and roadsides in Greater Vancouver (UBC: B. Klinkenberg 01-13). It is also occasionally planted in semi-natural sites. Often these plants are a genetic mix with other species. It is unclear to me whether this species is native to the Fraser Valley, but it does occur natively to the south in Washington, and may have spread naturally into the Lower Mainland, thus it is tracked as a rare native plant.


Megalodonta beckii (Torr. ex Spreng.) Greene - Asteraceae

A widespread aquatic in southern BC, it is known in the Fraser Valley only from Devil's Lake, Errock Lake (V: Ceska & Mitchell 1193) and Deer Lake (UBC: Warrington 608) in the eastern Fraser Valley. It rarely flowers in our area, but the opposite divided filiform leaves are unlike any other aquatic species here.

Muhlenbergia glomerata (Willd.) Trin. - Poaceae

Although this grass was collected by John Macoun from "damp places", Agassiz in 1889 [CAN: Macoun (22) 29,396], I had assumed this was a label mix-up as this species is not otherwise known west of the Coast Mts in BC. Surprisingly, in 2010 I discovered a population in a wetland east of Agassiz. It appears there is some calcareous influence from what looks to be a limestone patch on the mountain slope above the site. Muhlenbergia glomerata occurs extensively in calcareous sites throughout eastern and central BC as well as the extreme north. So it is no longer of conservation concern in BC, though this west coast site is remarkable.

Myriophyllum hippuroides Nutt. ex Torr. & A. Gray - Haloragaceae

In BC, this species is known only from the Fraser Valley, mainly on the north side of the Fraser from Pitt Meadows (UBC: Brink & McHale s.n.) to Mission, but also east to Harrison Mills (V: Ceska et al. C019). It can form dense stands in quiet water a meter or so deep and thrives in deep ditch sloughs and stagnant tidal backwaters. It is not as yet, on the whole, threatened by any development pressures.

Myriophyllum pinnatum (Walt.) Britton, Sterns & Poggenb. - Haloragaceae

A very local species of wet shores, boggy pools and ditches, and pools in emergent tidal flats. Known in BC only from a relatively small area along the Pitt River from Port Coquitlam (Minnekhada Regional Park - see Ceska & al. 1997) to Pitt Lake (UBC: Ceska 30362) and east of Lake Errock (Ceska & Ceska 30367). Also known from Washington (WTU: Zika 20196) and Oregon (V: Ceska & Ceska 26898; WTU: Zika 23482).

Myriophyllum ussuriense (Regel) Maxim. - Haloragaceae

This species has an unusual range. It is native to Asia and occurs in North America only in the Pacific Northwest; the main part of its range being in S BC and the Columbia River in the US (Ceska et al. 1986; Christy et al. 2000a, 2000b). It is restricted to emergent muddy and sandy shores where pools collect at least for part of the summer. In the Fraser Valley, it grows from the Fraser delta to Harrison Lake. In Greater Vancouver, it is known from about 20 sites along the Fraser and Pitt Rivers from Richmond to Pitt Lake to Barnston Island. The bulk of the Lower Fraser Valley plants are male. Female plants have been rarely seen in the Pitt River populations, but occur more commonly in the central and upper valley. Populations in the Fraser Valley are fairly secure because the habitat (muddy tidal flats) is not yet under development pressure. This will likely change in the future.

Persicaria hydropiperoides (Michx.) Small - Polygonaceae

A locally abundant species of sloughs, wet ditches, boggy pools, emergent lakeshores and ponds in the Fraser Valley from Vancouver to Popkum. Known from 11 sites in Greater Vancouver, it is especially frequent in the central valley around Chilliwack (UBC: Penny & Hartwell 186). It forms loose mats in shallow water with a muddy substrate, often covering whole shorelines. It does well in the deep ditches bordering agricultural fields, often fringing a dense border of Phalaris arundinacea L. It is recommended for removal from the British Columbia rare plant tracking list.

Persicaria punctata (Elliott) Small - Polygonaceae

This annual or perennial species is much like Persicaria hydropiper (L.) Spach, but is much less common. Ripe achenes are the best way to tell these two apart. Persicaria punctata is known from moist sites that are often disturbed. It is known from 8 sites in Greater Vancouver (UBC: Lomer 90-109), as well as an historic collection from Agassiz. It appears not to be threatened because of its ability to spread during disturbance, though its wetland habitat is often under threat. Populations are sporadic from year to year, but appear to be stable overall.

Pleuropogon refractus (A. Gray) Benth. ex Vasey - Poaceae

A very rare grass in the Fraser lowlands. Populations are known higher into the mountains on the north shore of the river. It grows in shaded wet sites usually by clear flowing streams and freshwater seeps. The nearest sites in the Fraser Valley are on the Seymour River (UBC: Lomer 97-67) and into the mountains in Coquitlam.

Potamogeton nodosus Poir. - Potamogetonaceae

This red-listed aquatic has proven to be quite rare in BC. The only sites recorded in BC so far are Burnaby (UBC: Lomer 89-199), Hatzic Lake (V: Nijman & Soar 2864), Fort Langley (V: Ceska et al. 1549), Pitt River (V: Mitchell 1675), Seabird Island (V: Nijman & Baillie 4696); Mission (V: Ceska et al. s.n.) in the Fraser Valley, and in the North and South Okanagan. Much more searching is needed to determine the full extent of its range in the Fraser Valley.

Potamogeton oakesianus J. W. Robins. - Potamogetonaceae

Not much is known of this aquatic species. It is known from near Mission (Ceska & Ceska 1980) and is to be expected in other lakes in the Fraser Valley, but so far new sites have not been found.

Potamogeton strictifolius Benn. - Potamogetonaceae

Not much is known of this aquatic species. In British Columbia it was first collected in Windermere Lake in 1972 (V: Newroth 2757). In 1977 it was collected in Kawkawa Lake near Hope (V: Warrington 4836) and reported by Ceska & Ceska 1980. It is to be expected in other lakes in the Fraser Valley, but so far new sites have not been found.

Pyrola elliptica Nutt. - Pyrolaceae

Usually a species of montane forests, this rather widespread evergreen herb occurs on islands in the Fraser near Agassiz (UBC: Lomer 6400). It is known from higher elevations in the Chilliwack Valley and there is an old collectionfrom Port Haney (Maple Ridge) in 1897 (UBC: Henry 26). It is to be sought in shaded coniferous forests in the area.

Rupertia physodes (Dougl. ex Hook.) J. Grimes - Fabaceae

This is an unexpected species in the Fraser Valley, but there is a small population still extant in south Surrey near the Langley border (UBC: A. Guppy s.n.). I would not expect it to occur elsewhere in the Fraser Valley, Though there may be other sites in the vicinity. It is associated with Salal in well drained gravelly sites and can spread into disturbed areas.

Salix sessilifolia Nutt. - Salicaceae

It appears this species is restricted to the Fraser Valley in BC. Though of relatively limited distribution, Salix sessilifolia is a dominant species of sandbars and sandy banks of the Fraser from Steveston to Hope, as well as up the Pitt River to Pitt Lake, Harrison River to Harrison Lake, and odd outliers such as at Silver Lake (UBC: Ceska 24171). It covers numerous Fraser River island shores especially in the upper Fraser Valley wherever sandbars form. Threats are few and it is well adapted to shifting sand and disturbance with its widely spreading root system and ability to sprout up from burial and cutting. It is too abundant and unthreatened to be called rare. Recommended for downlisting after several new sites are reported.

Sanguisorba menziesii Rydb. - Rosaceae

This perennial herb is believed to be derived from hybrids between Sanguisorba officinalis L. and S. canadensis L. Sanguisorba officinalis is infrequent in Sphagnum bogs in the Fraser Valley, mostly on the north shore of the Fraser River, while S. canadensis is found in the mountains on the south side of the Chilliwack Valley. Sanguisorba menziesii looks somewhat intermediate between the two, with heads of purplish flowers with dangling stamens. There is an historic record from Haney in 1949 (UBC: Krajina s.n.). It is expected to still be extant in the bogs on the north side of the Fraser River, but otherwise has gone unreported in recent times.

Sidalcea hendersonii S. Wats. - Malvaceae

This outstanding perennial with the hibiscus-like flowers is rather rare and sometimes threatened in its range outside of British Columbia (Love 2003). It grows along the coast from Oregon north to a recently discovered Population in Alaska (ALA Anderson 622 - V: photo). So new records north of Vancouver Island are to be expected. The bulk of the population resides in the Fraser delta from Iona Island south to Westham Island with scattered sites inland around Boundary Bay in Delta and Surrey (UBC: Prange 19). I estimate more than 90% of the British Columbia population can be found along the tidal shores and islands of the south arm of the Fraser River in Richmond and Delta. Indeed, it appears that more than 75% of the world's population of Henderson's checker-mallow grows along this 23 km stretch of river. It is common and co-dominant in vast areas of tidal swamp with Carex lyngbyei Hornem. and Phalaris arundinacea L. It is mainly an estuarine species that grows eastward in the delta only to Surrey, though there is an historical record from Milner in Langley.

Sphenopholis intermedia (Rydb.) Rydb. - Poaceae

Collected from dredged sand in Surrey, east of Vancouver (UBC: Lomer 93-73). This grass is known from the Thompson River, as well as other sites in BC, so seeds were probably washed down into the Fraser and sprouted in the dredging. In 2010 a single plant was observed on the sandy meadow shore of an island in the Fraser River southwest of Agassiz. So it appears this species can arise naturally from material washed down the Fraser River from interior sites, thus it should be considered native here.

Verbena hastata L. var. scabra Moldenke - Verbenaceae

Local in the Okanagan, very rare elsewhere in BC. This tall, erect, purple-flowered perennial was collected in Vancouver in 1917 (UBC: Perry s.n.), but decades passed before it was noted again in the Fraser Valley, this time near Chilliwack. Surprisingly it is not known from purely natural sites here such as along the Fraser River, but does occur in disturbed ground, wet fields, roadsides and ditches. Presently known from three sites. All populations are endangered by development. A large population by Hwy 1 and Annis Rd., southwest of Rosedale, was lost in 2008 to cornfield expansion, though it survives in the periphery. The Port Coquitlam site has been destroyed by a housing development, though some plants have remained in the disturbed ground fringing the development. A third site near Bridal Falls was discovered during the 2008 CDC survey (UBC: Lomer 6781). It is a small population in disturbed ground and may not persist through succession.

Wolffia borealis (Engelm. ex Hegelm.) Landolt ex Landolt & Wildi - Lemnaceae

Rarely seen in the Fraser Valley (Ceska & Ceska 1980), this miniscule aquatic plant looks like nothing more than green scum. It is proving to be more common than first thought, but is rather sporadic from year to year. New sites from Cultus Lake, Vancouver (UBC: Lomer 6754) and Cheam wetlands suggest it occurs from one end of the Fraser Valley to the other, especially in the central valley. It is not endangered as long as there are sloughs and Typha ponds and lakeshores. Easily overlooked, but uncommon nevertheless. It often grows with Lemna and Spirodella and is presumably spread by ducks so it can show up just about anywhere that ducks feed and where water is adequate. It can have explosive exponential growth late in the season, but is so tiny that only several square meters are covered in most instances.

Part V: Excluded Species

The following rare species have been collected in the Fraser Valley over the years, but are not considered to be native here. They may show up as waifs from time to time in sand dredgings from the Fraser River, railroad tracks, cultivated fields, or waste places and, in some cases, even become established from introduced populations originating from outside the province.

Actaea elata (Nutt.) Prantl

Found in the Chilliwack drainage, but not in the Fraser lowlands except on the lower slopes of Mt Cheam above the lowland zone.

Alopecurus carolinianus Walt.

There is an old record from Humphries St., Vancouver in 1912. This was most likely an introduction.

Anemone virginiana L. var. cylindroidea B. Boivin

There is an old collection from 1889 from Agassiz. It is believed to be mislabeled, as its occurrence here seems unlikely.

Apocynum x floribundum Greene

An old record from Cultus Lake is probably referable to A. cannabinum, but the specimen is not easy to determine with certainty.

Eleocharis rostellata (Torr.) Torr.

Reported from Pitt Lake and Vancouver, but no verifiable vouchers found. It would not be expected in the Fraser Valley.

Cardamine parviflora L.

This slender annual has been collected near the Fraser River in Coquitlam in 1991 (UBC: Lomer s.n.). It still occurs at the site today, but because it is unclear whether this population is native or European in origin it has been excluded.

Carex hystericina Muhl. ex Willd.

Collected from dredged sand in Coquitlam.

Carex sychnocephala Carey

Collected from dredged sand in Surrey.

Cyperus erythrorhizos Muhl.

Established as a weed in several cranberry fields from Delta to Harrison. Recently found away from these sites in Burnaby.

Eleocharis rostellata (Torr.) Torr.

Reported from Pitt Lake and Vancouver, but no verifiable vouchers found. It would not be expected in the Fraser Valley.

Epilobium ciliatum ssp. watsonii (Barbey) Hoch & Raven

Occurs in the Fraser delta, but too widespread and unthreatened in BC to be considered a rare plant.

Epilobium leptocarpum Hausskn.

Found by railroad tracks in Coquitlam. It also occurs as native on the North Shore Mountains.

Eragrostis pectinacea (Michx.) Nees var. pectinacea

Rare weed in waste places. Slated for removal from the rare plant list because BC plants are assumed to be introductions.

Glyceria x occidentalis (Piper) J. C. Nels.

Apparently this nothospecies is a hybrid between the native Glyceria leptostachya and the introduced G. fluitans from Europe. Until these hybrids can be separated from the G. fluitans plants that grow in the Fraser Valley it is best to exclude it at this time.

Isoetes nuttallii A. Braun ex Engelm.

Reports from North Vancouver were based on a misidentification. It may occur in seepage sites on the lower mountain slopes north of the Fraser River.

Lindernia dubia (L.) Pennell var. dubia

Rare weed in bare sites in cranberry fields in Delta and Piitt Meadows; presumed to be introduced from eastern North America.

Navarretia intertexta (Benth.) Hook.

Collected as a waif along railroad tracks in White Rock in 1988.

Nicotiana attenuate Torr. ex S. Watson

Collected from dredged sand in Surrey.

Potentilla paradoxa Nutt.

- Collected by railroad tracks and in dredged sand in Greater Vancouver.

Scirpus pallidus (Britt.) Fern.

Collected from dredged sand in Surrey and also from the natural Fraser shoreline nearby where it has spread.

Sphenopholis intermedia (Rydb.) Rydb.

Collected from dredged sand in Surrey.

Symphyotrichum frondosum (Nutt.) G. L. Nesom

Collected from dredged sand in Surrey and garden topsoil in New Westminster.


I would like to thank Adolf Ceska, Jamie Fenneman, Fred Ganders, Rose Klinkenberg, Jenifer Penny, Terry Taylor, and Peter Zika for their helpful comments.


Ceska A. & O. Ceska. 1980. Additions to the flora of British Columbia. Canadian Field-Naturalist 94: 69-74.

Ceska, A., O. Ceska & F. Lomer. 1997.Myriophyllum pinnatum, a new species for British Columbia. BEN # 171 July 30, 1997

Ceska, O., A. Ceska, & P.D. Warrington. 1986. Myriophyllum quitense and Myriophyllum ussuriense (Haloragaceae) in British Columbia, Canada. Brittonia 38: 73-81.

Christy J.A., O. Ceska & A. Ceska. 2000a. Noteworthy collections - Oregon. Myriophyllum ussuriense (Regel) Maxim. new in Oregon. Madroño 47: 212.

Christy J.A., O. Ceska & A. Ceska. 2000b. Noteworthy collections - Washington. Myriophyllum ussuriense (Regel) Maxim. new in Washington. Madroño 47: 212-213.

Fabiszewski, J. & J. Cebrat. 2003. Coleanthus subtilis (Tratt.) Seidel - a new species to the Polish vascular flora. Acta Soc. Bot. Poloniae 72: 135-138.

Hejny, S. 1969. Coleanthus subtilis (Tratt.) Deidl in der Tschechoslowakei. Folia Geobot. Phytotax. 4: 345-399.

Love, R.M. 2003. Henderson's Checkermallow (Sidalcea hendersonii): Part 2. Summary of what is currently known about the global distribution of Sidalcea hendersonii (Malvaceae). BEN # 306 March 22, 2003

Necajev, A.P. & A,A, Necajev. 1972. Coleanthus subtilis (Tratt.) Seidl in the Amur Basin. Folia Geobot. Phytotax. 7: 339-347.

Nechaev AP, Nechaev AA. 1973. Coleanthus subtilis (Tratt.) Seidl. v priamurskoi chasti areala. [Coleanthus subtilis (Tratt.) Seidl. in the Amur part of its area.] Bot. Zhurn. 58. (3): 440-446.

Taran, G.S. 1994. Floodplain Ephemeretum of Middle Ob - a New Class for Siberia, Isoëto-Nanojuncetea Br.-Bl. et Tx. 1943 on the Northern Border of Expansion. Siberian Journal of Ecology 5: 578-582.

Woike, S. 1969. Beitrag zur Verkommen von Coleanthus subtilis (Tratt.) Seidl (Feines Scheidenbluetgrass) in Europa. Folia Geobot. Phytotax. 4: 401-413.


Recommended citation:  Author, date, page title. In: Klinkenberg, Brian. (Editor) 2023. E-Flora BC: Electronic Atlas of the Flora of British Columbia []. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Date Accessed]

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