Flora of the Canadian Arctic Archipelago


S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, L.J. Gillespie, A.K. Brysting, H. Solstad, and J.G. Harris

Pedicularis lapponica L.

English: Lapland lousewort,

French: Pédiculaire de Laponie.

Scrophulariaceae, Fernweed family.

Published in Sp. Pl. 609. 1753.

Type: Described from northern Sweden.

Vegetative morphology. Plants (5–)10–20(–25) cm high; perennial herbs; not caespitose. Taproot present. Ground level or underground stems horizontal; rhizomatous; elongate (and branching); 0.4–0.7 mm wide. Caudex absent (slender branching rhizome present). Aerial stems erect. Aerial stem trichomes present, or absent; appressed (pubescent, white or transparent with purplish end walls). Leaves present; heterophyllous; distributed along the stems; alternate; dying annually and non-persistent. Petioles present (basal leaves), or absent (leaves near the inflorescence; basal leaves rarely collected); 2–30 mm long (on the basal leaves, short on the leaves near the inflorescence); winged (rachis broad); glabrous. Leaf blades simple. Leaf blade bases attenuate. Blades 10–25(–35) mm long, 3–9 mm wide, spreading, linear or lanceolate (narrowly, basal leaves pinnately divided into 12–30 linear divisions, 1–2 mm long and less than 1 mm wide; upper leaves with a broad rachis), flat, appearing single-veined. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blades cut into linear divisions. Blade margins entire (leaves subtending the flowers) or dentate (on leaf divisions of the basal leaves), glabrous; apices acute.

Reproductive morphology. Flowering stems solitary. Flowering stems circular or oval in cross section. Flowering stems with leaves. Flowering stems hairy. Flowering stems puberulent. Flowering stem hairs simple (and floccose); white or translucent, or transparent with deep purple cross-walls; glandular hairs absent. Inflorescences spicate, or racemose; terminal; dense; globose or sub-globose (in bud), or oblong (elongating in flowering and fruiting); 1–4 cm long; (15–)20–35 mm wide; elongating as the fruit matures. Pedicels present (1–2 mm long), or absent (inconspicuous; flowers borne in the axils of leaves similar to the basal leaves, but smaller). Floral bracts purplish red (shorter than the flowers). Flowers per inflorescence numerous; bilaterally symmetrical (zygomorphic). Sepals conventional; 5; fused; 4–6 mm wide; purplish red. Calyx tubular (open for about half the length on the abaxial side); 5-lobed (shallowly, or poorly defined); glabrous. Petals conventional; fused; 5; yellow (pale), or pink (tinges sometimes on the helmet); with contrasting markings (colour contrast), or without contrasting markings; (12–)14–16(–20) mm long (the arching helmet petals slightly longer than the lower petals). Corolla bilabiate; 2-lobed (helmet), or 3-lobed (lip or landing petal); helmet prolonged into a long beak; helmet without 2 small teeth at the apex. Stamens 4; stamen filaments markedly unequal in length (seen as two dark positions in the helmet before anthesis); stamen filaments glabrous; fused to the corolla. Anthers ellipsoid; 2–2.3 mm long. Nectaries present (and prominent on one side of the ovary). Ovary superior; carpels 2; syncarpous. Ovaries inverse turnip-shaped (conical); glabrous. Styles 1; 16–20 mm long; straight. Stigmas per ovary 1. Placentation axile. Ovules per ovary few, 10–20. Fruit with calyx persisting; dry; a capsule; broadly lanceolate (or ovoid, curved, acuminate, 1.5 times as long as the calyx); yellowish; 6–8 mm long; 2.8–3.2 mm wide; glabrous; surface venation ribbed (veins prominent); distinctly flattened; dehiscent; opening at the apex and partially or fully down one side. Seeds few, 10–20; 0.8–1 mm long; yellowish (testa), or brown (seed seen inside the loose testa); surfaces rugose (slightly).

Chromosome information. 2n = 16.

(2n) (2x) = 16. Löve and Löve (1944b, northern Europe; 1982a, Arctic Canada); Harmsen, in Löve and Löve (1948, Greenland?); Sørensen and Westergaard, in Löve and Löve (1948, Greenland); Harmsen, in Jørgensen et al. (1958, Greenland); Sokolovskaya and Strelkova (1960, 1962); Sokolovskaya (1962, 1968, northeastern Asia, Koryak); Sorsa (1963b, Finland); Laane (1965, northern Norway); Zhukova (1966, northeastern Asia); Knaben and Engelskjøn (1967, southern Norway); Zhukova et al. (1977, northeastern Asia); Krogulevich (1978, southern and northern Siberia); Zhukova (1980, northeastern Asia); Dalgaard (1988, western Greenland).

Ploidy levels recorded 2x.

Ecology and habitat. Substrates: wet meadows, ridges; moderately well-drained areas; rocks, gravel, moss; with high organic content, peat; acidic (Elven (personal communication, 2005) noted that in his experience with this species (Europe, Siberia, North America) it is a more or less acidophilic one.). "In rather dry turfy places", Porsild (1957); moist grassy slope (CAN 97916); disturbed gravel (CAN 466165); dry exposed calcareous ridge, drainage good (CAN 368152); Vaccinium uliginosum, lichen, Cassiope and sedge - hillocky, rocks by lake (CAN 258828); growing in thick moss (CAN 541740); low-lying meltwater pool below north slope of moraine (CAN 517994); common on steeply west-sloping dry to mesic slope on sandy ground and thin turf with Empetrum, Cassiope tetragona, and Dryas integrifolia (CAN 549907).

North American distribution. Alaska, Yukon, continental Northwest Territories, Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic islands: Baffin (southeastern), Southampton (Digges).

Northern hemisphere distribution. Circumpolar, or circumboreal. Northern Fennoscandian, Kanin–Pechora, Polar Ural – Novaya Zemlya, Yamal–Gydan, Taimyr – Severnaya Zemlya, Anabar–Olenyok, Kharaulakh, Yana–Kolyma, West Chukotka, South Chukotka, East Chukotka, North Alaska – Yukon, Central Canada, Labrador – Hudson Bay, West Greenland, East Greenland.

General notes. Polunin (1940) commented that this delightful species, which in Lapland is sometimes almost the only bright flower to be seen in miles of parched, lichen-birch-scrub, is plentiful and apparently without marked variation in the southern parts of the Arctic Archipelago where it flowers abundantly and generally manages to ripen fruit. In Canada it grows in rather dry, heath areas, being supposedly parasitic on the roots of the dominant ground-shrubs. It also grows in the less swampy parts of marshes. The plants are generally gregarious and propagate by long, slender runners.

Porsild (1957) described the helmet as prolonged into a long beak, and the image library illustrates the snorkel-hood-like end to the helmet petals. Mayer (1972), in describing the species in Flora Europaea, described the beak as rather short, which may be the case when this species is compared with other species that occur in northern Europe.

The flowers are very fragrant.

MacInnes and Cavers (1971) reported on the reproduction of this species in Nunavut, at McConnell River, 60°50'N, 94°25'W, after a study that lasted 3–4 years. They found the average number of seeds per plant, per reproductive attempt, was 8 for this species, approximately 2% of the estimated potential output. Inadequate pollination was suggested as the problem, as P. lapponica did not set seed in insect exclusion experiments. Of the reproductive attempt 23% of some flowers, capsules, ovules, and developing seeds were destroyed by insects and other animals.

Nilsson and Svensson (1997) studied the host affiliation in Bartsia alpina and Pedicularis lapponica using visual examination of root connections and C14 labelling to identify host ranges of these two hemi-parasitic angiosperms. They found that labelling with C14 was more sensitive than root examination, since seven additional host species and three new host families were found using the former method. In total, 18 host species belonging to 11 families were found. Most of the hosts were members of the Cyperacea. Not all species tested using C14 labelling were found to be hosts, and there was no preference for host species with large root systems. Both hemi-parasites formed connections with Pinguicula vulgaris, which has a very small and stunted root system compared with the root system of larger plants such as Betula species. The conclusion was that the mere presence of another species growing close to a hemi-parasitic plant does not mean that this plant is used as a host.

Freytag and Weber (1987) found that Pedicularis lapponica and P. hirsuta are not host specific. Preferred hosts are Salix species, owing to their frequent occurrence in the habitat of the Pedicularis species or a possible stimulation from the ectomycorrhizal roots of the Salix plants. These Pedicularis species do not show serious injury at the host roots. All parasitic roots are able to attack host roots. Development of the Pedicularis haustoria and the morphological-anatomical structures are typical for the Rhinanthoideae. Just 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.

Williams and Batzlli (1982), in a study of five species of Pedicularis at Atkasook, Alaska, which rely on bumblebees for pollination, found P. lapponica had the smallest shoots and produced few seeds even though pollination success was high.

Illustrations. • Habitat. Close-up of Pedicularis lapponica. Manitoba, Churchill. 3 July, 1956. Mildred and Raymond D. Wood Collection. CMN Photo library S78–225. • Herbarium specimen: Base of plant. Slender branching rhizome and basal leaves, not often present on herbarium specimens. CAN 438337. • Close-up of plants. Plants with creamy yellow flowers borne on a single (i.e., unbranched) flowering stem. Note the reddish purple fused calyx that is much shorter than the petals. Nunavut, Baffin Island, Soper River Valley, Mt. Joy. Aiken and Iles 02–021. CAN. Scale bar in cm. • Close-up of inflorescence. Inflorescence racemose, but spike-like and dense. Note the purplish red calyx with teeth about 0.5 mm long on the adaxial surface and partially open on the abaxial surface. The corolla helmet is pale cream and somewhat purple-tinged on the long beak. Aiken and Iles 02–021. CAN. • Close-up of inflorescence. Compact inflorescence with 6–7 flowers, creamy white petals, and with helmet petals that have a long 'snorkle-hood-like' beak. Calyx is purple with teeth towards the adaxial surface. Nunavut, Baffin Island, Iqaluit. 19–30, July 1982. J.M. Gillett. No voucher. • Surface view of inflorescence. Note dark reddish fused calyx, slightly open on the dorsal surface, narrow helmet petals and wide flaring landing petals. Nunavut, Baffin Island, Iqaluit. 24 July, 2005. Photograph Kathy Thornhill. • Close-up of plant. Drawing by Mrs. S. Bergh and Mrs. L. Barstad based on a collection from [Svalbard, Nordenskiöld Land, Advent Point.](The plant is probably from mainland Norway. There must have been a label confusion.] 1911. A. Mathey Dupraz. O 213872. With permission of the Botanical Museum, University of Oslo, Norway. • 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.