|Furbish lousewort, Furbish's wood betony|
|Elizabeth J. Farnsworth|
The following Participating Institutions are custodians for this species in the CPC National Collection:
New England Wild Flower Society
The conservation of Pedicularis furbishiae is fully sponsored.
Elizabeth J. Farnsworth contributed to this Plant Profile.
Pedicularis furbishiae is a narrow endemic, found only along 225 km of the pristine St. John River system of Maine and adjacent New Brunswick. Kate Furbish, botanist and wildflower artist, discovered the plant in 1880, and it has been intensively studied ever since. One of the first plants to receive concerted conservation attention in North America in the 1970's, Pedicularis furbishiae is a poster-child for conservation biology, and an exemplary case study for understanding the complex phenomena associated with metapopulations. A string of ephemeral sub-populations (demes) establish along the river's edge and persist for a short time before ice-scouring by the wild river destroys them and hurries their seeds downstream, where the plants re-establish and begin the cycle again. The future is precarious for Pedicularis furbishiae; river dams, climatic change, increasing run-off, pollutants, recreationists, and invasive species all can impact its fragile riverine habitat. Only a highly coordinated, international strategy can protect the St. John watershed and the large-scale natural processes that shape the community of Pedicularis furbishiae and many other rare species. Ambitious efforts are underway.
Pedicularis furbishiae is an herbaceous perennial. Its distinctive, deeply lobed, toothed, and hairy leaves (4 to 20 cm long) grow in a basal rosette. In late July and August, reproductive plants send up a flowering spike (scape) up to 1 m tall, with a cluster of tubular, yellow flowers 2 cm long, each subtended by a stout bract. The fruits are oval capsules with small (2mm long), gray seeds.
Distribution & Occurrence
Pedicularis furbishiae grows mainly on north- or northwest-facing, narrow strips of steeply sloping river banks, usually associated with groundwater seeps in relatively circumneutral, gravelly soil left by glaciers (USFWS 1991, Maine Department of Conservation 1999, COSEWIC 2001). These riverside areas are frequently scoured and eroded during the ice break-up of the spring melt (which is a spectacle on the St. John River, due to its unique geomorphology [Kite 1983]), and may be denuded of vegetation in places. The climate is continental and cold, with long winters and short growing seasons (USFWS 1991).
On the New Brunswick side of the river, the plant grows in three distinct areas: 1) the first on gravelly calcareous soil about 8 m away from the water's edge, at the shade line of the forest; 2) the second in a more sunny, eroded bank strewn with cobbles; and 3) on the east bank of a shady railroad cut more than 400 m from the river's edge in drier, sand and gravel soils (COSEWIC 2001). In Maine, plants are found in about a dozen or more sub-populations (variable from year to year) clustered mainly along the river's edge. Systematic ecological surveys have revealed that Pedicularis furbishiae is associated with riverbank areas that have typically suffered ice scour within the past 3 to 10 years, and are steeper, wetter, and characterized by high species richness relative to areas not supporting the taxon (Gawler 1988, Menges 1990).
Plant species associated with Pedicularis furbishiae include a variety of riverside taxa commonly associated with northern (or western) rivers with rich bedrock, as well as several rare species: Alnus spp., Anemone canadense, Arnica mollis, Aster spp., Astragalus alpinus var. brunetianus, Calamagrostis canadensis, Carex spp., Castilleja septentrionalis, Chrysanthemum leucanthemum, Conioselinum chinese, Cornus stolonifera, Diervilla lonicera, Equisetum arvense, Equisetum variegatum, Fragaria virginiana, Gentiana amarella, Hedysarum alpinum var. americanum, Juncus alpinus, Listera auriculata, Myrica gale, Oxytropis campestris var. johannensis, Parnassia glauca, Prenanthes racemosa, Primula mistassinica, Rubus pubescens, Solidago spp., Tanacetum huronense var. johannense, Thalictrum polygamum, Tofieldia glutinosa, Trifolium repens, Trifolium pratense, Taraxacum officinale, Vicia cracca, and Viola novae-angliae. The upland forest adjacent to (and sometimes overhanging) Pedicularis stands commonly consists of the conifers Abies balsamea, Picea rubens, Picea glauca, Thuja occidentalis, with scattered broadleaf species, Acer spicatum, Betula lutea, and Populus balsamifera (USFWS 1991, Virginia Tech 2001).
|Populations of Pedicularis furbishiae fluctuate in numbers and location dramatically from year to year, and are notoriously difficult to delineate (Gregory and Gawler 1990). However, the U. S. Fish and Wildlife Service (1991) estimated the total population to be 13,800 non-reproductive individuals and 4,300 flowering individuals (an increase from the approximately 5,000 stems estimated in 1980).|
Conservation, Ecology & Research
Pedicularis furbishiae is an herbaceous perennial plant that can take up to three years to reach reproductive maturity (USFWS 1991). Tiny seedlings emerge, usually favoring wet soil, in June and July (Gawler et al. 1987). Mature plants leaf out in late May, when flood waters recede and before the majority of other plants have leafed out.
Plants reproduce solely by sexual reproduction, and can successfully self-pollinate as well as out-cross (Waller et al. 1988).
The common bumblebee, Bombus vagans, is the primary pollinator (Macior 1978).
Reproductive output is positively correlated with age (and size) of the plant (Gawler et al. 1987).
The proportion of seeds that successfully mature is regulated by pre-dispersal herbivory on the parent plant, and by a seed predator, the plume moth, Amblyptilia picta (Menges et al. 1986).
Seeds mature and disperse in the fall and are likely dispersed by wind and water, but the majority of seedlings appear to establish under or close to the parent plant.
Like many members of the Scrophulariaceae, Pedicularis furbishiae is thought to be a hemi-parasite (Musselman and Mann 1977), relying on haustorial root connections with a host plant to derive some of its nutrients. Nitrogen levels are low in the soils in its habitat (Virginia Tech 2001), so this symbiosis may be important in fostering early growth of the plant. No haustorial connections have been observed in the field (USFWS 1991), but excavation is difficult, making such connections hard to detect.
Cultivation experiments at the New England Wild Flower Society (NEWFS) have grown Pedicularis furbishiae seedlings with little bluestem grass and with clover (Trifolium sp.) to test for potential hemi-parasitism, but survivorship was poor (W. E. Brumback, NEWFS, personal communication). Host-specificity and the role of hemi-parasitism in the persistence of this species remains a mystery.
Extensive demographic modeling using data on this plant indicate that the global population persists through a dynamic series of local extinctions (brought on by ice scour) and recolonization events (Gawler 1988, Menges 1990). In fact, this species provided one of the first model systems for studying such metapopulation dynamics, contributing to new paradigms in the science of conservation biology (Schemske et al. 1994).
New demographic analyses have produced more refined projections for the future of Pedicularis furbishiae (e.g., Silvertown et al. 1996). However, the data still reinforce the notion that a whole-watershed approach is necessary to protect the large-scale dynamic processes that maintain multiple, ephemeral, mobile populations of this and other neighboring riverine species on the landscape.
Garbage dumping and excavation along gravel shores that reduces habitat availability
Forestry practices (upland clearing) that inc
Susan C. Gawler (Maine Natural Areas Program, Augusta, Maine) completed her dissertation on the ecology of the taxon.
Jonathan Silvertown (Open University, United Kingdom) uses Pedicularis furbishiae as a model system for studying the demography of rare plants (for a description of his work in collaboration with Miguel Franco (Universidad Autonoma de Mexico, Mexico City).
The New England Wild Flower Society (Framingham, Massachusetts) has conducted germination trials on Pedicularis furbishiae. Seeds treated with moist cold germinate well, and seeds stored for three years were able to germinate. However, survivorship following germination, even when experimenting with host plants, has been poor.
C. Wheeler (University of Akron, Akron, Ohio) performed experiments on seedling development and hemiparasitism in 1980 toward a Master's thesis.
The Nature Trust of New Brunswick established a protected zone called the George Stirrett Nature Preserve around one of the three Canadian populations in 1990 (COSEWIC 2001). A plan existed in 1998 to transplant certain vulnerable plants from an eroding site to this preserve (Hinds 1998); but updates are needed.
The Maine Natural Areas Program has been involved with landowner education regarding Pedicularis furbishiae for over a decade (U. S. Fish and Wildlife Service 1991)
Cooperative agreements are being forged between the United States and Canada regarding joint protection of several endangered species, including Pedicularis furbishiae.
Ecological studies to determine factors that limit recruitment of seeds and seedlings to available habitat
Studies of the importance of hemi-parasitism in the persistence of this species
Quantitative hydrological studies that monitor changes in flooding and ice-scouring along the river and their impacts on the plant
Scoggan, H.J. 1978. The Flora of Canada. National Museums of CA, Publications in Botany.