Flora of the Canadian Arctic Archipelago
English: Hairy lousewort,
French: Pédiculaire hirsute,
Scrophulariaceae, Fernweed family.
Published in Sp. Pl. 609. 1753.
Type: Described from northern Sweden.
Vegetative morphology. Plants 5–15(–25) cm high; perennial herbs. Taproot present (pale and spindly in young plants; well developed in older plants). Ground level or underground stems vertical, or horizontal (rarely). Caudex present (a short zone at ground level, 20–30 mm in diameter in old plants). Aerial stems erect. Aerial stem trichomes present; appressed, or spreading. Leaves heterophyllous; distributed along the stems (and in a basal tuft); alternate; dying annually and non-persistent (flowering stem leaves), or marcescent (basal leaves). Petioles present (basal leaves), or absent (leaves near the inflorescence); (2–)5–20 mm long (long in the basal leaves; short in the bract leaves); winged, or not winged; hairy; woolly. Petiole hairs longer than the diameter of the petiole; spreading; floccose. Leaf blades simple (pinnately divided; the basal leaves fern-like with 10–24 oblanceolate leaf divisions; 2–6.5 mm long and 2–3.5 mm wide; the stem leaves usually with a broad rachis to 3.5 mm wide). Leaf blade bases truncate. Blades (10–)15–25 mm long, 2–5 mm wide, spreading, somewhat curled, linear or lanceolate, flat, veins pinnate. Blade adaxial surface glabrous (usually; petiole hairs may be present at the base of the blade). Blade abaxial surface glabrous (green). Blades cut into linear divisions. Blade margins entire or crenate or dentate (that is, the margins of the leaf blade divisions), glabrous; apices acute.
Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves. Flowering stems hairy. Flowering stems woolly. Flowering stem hairs simple; shorter than the diameter of the flowering stem (near the base of the plants), or longer than the diameter of the flowering stem (near the inflorescence); white or translucent; glandular hairs absent. Inflorescences spicate; terminal; dense; globose or sub-globose (sub-capitate but soon elongating); 3–6 cm long (sometimes to 10 cm long in fruit); 20–30 mm wide; elongating as the fruit matures. Pedicels present, or absent (often lying against the flowering stem and difficult to see among the dense, woolly hairs). Flowers bilaterally symmetrical (zygomorphic). Sepals conventional; 5; fused; 4–5 mm wide; green, or purple, or pink, or yellow (cream; drying membranous with a dark line in the position of the midvein of each sepal). Calyx tubular (with triangular, acute teeth); 5-lobed; hairy. Calyx hairs woolly; non-glandular; white or translucent. Petals conventional; fused; 5; white and pink; with contrasting markings (top of the helmet pink, elsewhere petals cream); 11–13 mm long (helmet petal 2.5–3 mm wide in side view). Corolla bilabiate; 2-lobed (helmet), or 3-lobed (lip or landing petal); helmet not prolonged into a long beak (but short and stubby); helmet with 2 small teeth at the apex (these minute). Stamens 4; stamen filaments markedly unequal in length (lying in pairs in two positions in the helmet); stamen filaments glabrous; fused to the corolla. Anthers 1.2–1.5 mm long. Ovary superior; carpels 2; syncarpous. Ovaries ovate; glabrous. Styles 1; 10–12 mm long; straight. Stigmas per ovary 1. Placentation axile. Ovules per ovary few. Fruit stalked; with calyx persisting; dry; a capsule; broadly lanceolate; golden brown (calyx like bladder campion); 6–7 mm long; 2–3 mm wide; hairy; surface appearing veinless (except that the midvein of each lobe is dark purple); distinctly flattened; dehiscent; opening at the apex and partially or fully down one side. Seeds few; 15–25; 1.2–1.8 mm long; yellowish, or brown; surfaces smooth.
Chromosome information. 2n = 16.
2n, 2x = 16. Harmsen, in Löve and Löve (1948, Greenland?); Löve and Löve (1948, northern Europe; 1956, Iceland; 1982a, Arctic Canada); Sørensen and Westergaard, in Löve and Löve (1948, Greenland); Holmsen (1952, Greenland); Harmsen, in Jørgensen et al. (1958, Greenland); Jørgensen et al. (1958, Greenland); Knaben and Engelskjøn (1967, northern Norway, two counts); Hedberg (1967, northern Canada); Dalgaard (1988, western Greenland).
Ploidy levels recorded 2x.
Ecology and habitat. Substrates: along streams, lakeshores, cliffs, flood plains; imperfectly drained moist areas, dry; rocks, gravel, sand, and silt; with low organic content and peat; calcareous. Moist stony places in the tundra and by lake and river banks (Porsild 1957).
North American distribution. Alaska, Northwest Territories Islands (?), continental Northwest Territories (?), Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Common (where it occurs). High Arctic. Arctic islands: Baffin, Devon, Ellesmere, Axel Heiberg, Parry islands (Bathurst, Melville), Somerset, Southampton, Coats (Bylot, Digges, Nottingham, Prince Charles islands and Melville Peninsula).
Northern hemisphere distribution. Circumpolar (with a Beringian gap). Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, AnabarOlenyok, Kharaulakh, YanaKolyma, West Chukotka, Wrangel Island, North Alaska Yukon, Central Canada, Labrador Hudson Bay, Ellesmere Land Peary Land, West Greenland, East Greenland.
General notes. In northwestern Greenland and on Ellesmere and Baffin islands, a form intermediate between P. hirsuta and P. langsdorffii (arctica) is found. It has the general habit of P. hirsuta but has the larger flower and minutely dentate helmet of P. arctica (Porsild 1957).
Elven (personal communication, 2005) commented that hybrids between any (northern) Pedicularis species have not been proved, even if small and/or large plants are sometimes misinterpreted as such. The occurrence of such intermediates should therefore be thoroughly documented before the concept is accepted.
Freytag and Weber (1987) found that the hemi-parasites Pedicularis lapponica and P. hirsuta are not host specific but preferred hosts in the genus Salix, owing to their frequent occurrence in the habitat of the Pedicularis species or possibly because of stimulation from the ectomycorrhizal roots of the Salix plants. These Pedicularis species do not seriously injure the host's roots. Development of the Pedicularis haustoria and the morphological-anatomical structures are typical for members of the Rhinanthoideae. In respect to the xylem system of the haustorium, these species showed differences when compared with middle European Pedicularis species. The xylem system has much more volume, which is a result of procambium-like cells that are derivatives of the pericycle.
This is reported to be one of 2–3 species of Pedicularis that occur north of the distribution of bumblebees. Fly pollination in species of Pedicularis was observed by MacInnes (1972) and documented in specimens deposited in the Agriculture Canada, Department of Entomology, collection (MacInnes, personal communication).
Illustrations. • Whole plant with root. Plant dug up to show root structure, i.e. caudex region, between roots and purple stems. Note the green fern-like leaves distributed along the stem and relatively small pale pink flowers. Nunavut, Baffin Island, Ogac Lake. Aiken and Leblanc 2004. • Close-up of roots. Plant dug up to show root structure. Note caudex region covered with the brownish remains of leaf bases between roots and purple stems, green fern-like leaves distributed along the stem. Nunavut, Baffin Island, Ogac Lake. Aiken and Leblanc 2004. • Habitat: Iqaluit. Dense Low Arctic tundra with Pedicularis flammea near the marker and pale pink flowering heads of Pedicularis hirsuta. Nunavut, Baffin Island, Iqaluit, near Upper Tundra Valley. 28 July, 2005. Aiken. No voucher. • Habitat: Baffin Island. Plant growing with Salix herbacea. Note the purplish, pinnately divided simple leaves, the stems that are becoming increasingly hairy towards the inflorescence, and the two-toned flowers. The stubby helmet is shorter than the three-lobed lower lip. Nunavut, Baffin Island, Iqaluit. July 24, 1982. J.M. Gillett 19014. CAN. • Close-up of plant. Plant growing in willow tundra. Note fern-like leaves distributed up the flowering stem, limited hirsute pubescence on the stem, and relatively small pale pink flowers. Nunavut, Baffin Island, Ogac Lake. Aiken and LeBlanc 2004. No voucher. • Habitat: Baffin Island. Flowering plants growing among willow, legume and sedges. Nunavut, Baffin Island, Iqaluit. Aiken 02–002. CAN. • Close-up plant. Note the deeper pink colour on top of the short stubby helmet. The expanded landing portion of the other three petals is pink, with a vivid pink throat where all the petals fuse to form a tube. Gillett 19014. CAN. • Close-up of flowering plant. Plant in early flowering stage. Norway, Svalbard, Sassen. July, 1997. Photograph by R. Elven. • Close-up of inflorescence. Inflorescence with pale pink flowers, deeper pink at the round ends of the helmet petals, and with landing petals slightly longer than the helmet. Nunavut, Baffin Island, Iqaluit. Aiken 02–002. CAN. • Close-up of albino plant. Albino plant with pale yellow-green leaves. White hairs responsible for the name "hirsuta" are highlighted by back lighting. Inflorescence setting seed. Flowers had been white. Aiken 98–001. CAN. Photograph by Mollie MacCormac. • Plant setting seed. Inflorescence setting seed. Plants growing near those in the previous image. Aiken 98–001. CAN. Photograph by Mollie MacCormac. • Inflorescence setting seed. Side view, upper right-hand flower shows the arched helmet petals, and the three landing petals in the position they are forced into when an insect enters the flower. Aiken 98–011. CAN. Photograph by Mollie MacCormac. • Arctic Island Distribution.
This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.
Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.
Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa..