Flora of the Canadian Arctic Archipelago
English: Fernweed, lousewort,
Scrophulariaceae, Fernweed family.
Published in Sp. Pl. 607. 1753.
Vegetative morphology. Plants (2–)5–15(–30) cm high; perennial herbs; caespitose, or not caespitose. Taproot present (usually), or only fibrous roots present (P. sudetica). Ground level or underground stems horizontal, or vertical, or absent; 0.4–7 mm wide. Caudex present, or absent. Aerial stems erect. Aerial stem trichomes present, or absent; appressed, or spreading, or erect. Leaves heterophyllous; mainly basal, or distributed along the stems; alternate; dying annually and non-persistent, or marcescent. Petioles present (basal leaves), or absent (leaves near the inflorescence); (0.5–)10–45(–75) mm long; winged, or not winged; glabrous, or hairy, or glabrescent; puberulent, or villous, or woolly (if applicable). Petiole hairs shorter than the diameter of the petiole, or longer than the diameter of the petiole; spreading; floccose, or curved, or wavy. Leaf blades simple (basal leaves pinnately divided). Leaf blade bases truncate (basal leaf divisions erect), or attenuate. Blades 6–50(–75) mm long, 2–13(–15) mm wide, spreading, straight or somewhat curled, linear or lanceolate or oblanceolate or obovate, flat, veins pinnate or appearing single-veined. Blade adaxial surface glabrous or hairy, hairs puberulent or woolly, hairs simple, hairs sparse or moderately dense, hairs white, or translucent. Blade abaxial surface glabrous or hairy, hairs puberulent or woolly, hairs sparse or moderately dense, hairs white, hairs straight or curved or wavy, hairs appressed or spreading. Blades lobed or cut into linear divisions. Blade margins crenate or dentate or deeply divided, glabrous or with non-glandular hairs; apices acuminate, or acute, or obtuse, or rounded.
Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves, or without leaves. Flowering stems hairy. Flowering stems puberulent, or woolly. Flowering stem hairs simple (floccose); shorter than the diameter of the flowering stem, or longer than the diameter of the flowering stem; white or translucent, or transparent with deep purple cross-walls; glandular hairs absent. Inflorescences spicate, or head-like; terminal, or lateral; dense, or diffuse; oblong, or globose or sub-globose, or cylindrical; 1–9(–10) cm long; 5–35(–40) mm wide; elongating as the fruit matures, or not elongating as the fruit matures. Pedicels present, or absent (flowers often sub-sessile). Floral bracts green, or purplish red. Flowers large; bilaterally symmetrical (zygomorphic). Sepals conventional; 5; fused; 4–13 mm wide; green, or yellow, or purple, or black, or pink, or purplish red; herbaceous. Calyx tubular, or bell-shaped; 4-lobed, or 5-lobed; glabrous, or hairy. Calyx hairs puberulent, or woolly; non-glandular; white or translucent. Petals conventional; fused; 5; white, or yellow, or red, or pink, or purple; with contrasting markings (usually), or without contrasting markings; 10–330 mm long. Corolla bilabiate; 2-lobed (helmet), or 3-lobed (lip or landing petal); helmet prolonged into a long beak (P. lapponicia), or not prolonged into a long beak; helmet with 2 small teeth at the apex, or without 2 small teeth at the apex. Stamens 4; stamen filaments markedly unequal in length, or all equal in length; stamen filaments glabrous, or hairy for the full length, or hairy at base only; fused to the corolla. Anthers purple, or reddish, becoming yellow, or yellow; ellipsoid; 1.2–3.5 mm long. Nectaries present. Ovary superior; carpels 2; syncarpous. Ovaries ovate, or inverse turnip-shaped; glabrous. Styles 1; 10–30 mm long; straight. Stigmas per ovary 1. Placentation axile. Ovules per ovary few 10–20. Fruit sessile, or stalked; with calyx persisting; dry; a capsule; ovoid, or elongate-cylindrical, or urceolate, or broadly lanceolate; yellowish, or black, or brown, or red, or golden brown, or straw-coloured; 6–20 mm long; 2–6.5 mm wide; glabrous, or hairy; surface venation reticulate, or appearing veinless, or venation ribbed; distinctly flattened; dehiscent; opening at the apex and partially or fully down one side. Seeds 0.5–3 mm long; black, or brown, or yellowish; surfaces smooth, ridged, reticulate, rugose.
Chromosome information. 2n = 16.
General notes. Ivanova and Yurtsev (1980) and Ivanova (1991) discussed the genus Pedicularis in Russia.
Subgenera that have been recognised in the genus are Sceptrum (sect. Capitatae, Sceptrum), Pedicularis (sect. Edentulae, Pedicularis, Pharyngodon, Rostratae), and Verticillatae (sect. Verticillatae).
Macior (1975) reported on the pollination ecology of Pedicularis in the Yukon Territory, Kluane Range of the St. Elias Mountains. He found that seed production in all six species that occur in the area (P. capitata P. lanata (kanei), P. langsdorffii, P. labradorica, P. sudetica, and P. verticillata) depended on bumblebees (Bombus species). Asexual propagation by root and crown branching was present in P. capitata and P. langsdorffii. Cinematographic and stereophotographic records indicated that bumblebee queens forage in an upright (nototribic) position for nectar and pollen. Bombus workers forage upright on P. verticallata, inverted on P. labradorica, and in both positions on P. capitata, P. lanata, P. langsdorffii, and P. sudetica. The potential for hybridisation between Pedicularis species by reason of overlapping blooming periods, sharing of the same or adjacent habitats, and recovery of individually marked pollinators was noted. Analysis of 1402 corbicular pollen loads from 1769 pollinating bumblebees of 14 species of Bombus on Pedicularis revealed equal numbers of pure and mixed loads were collected. This suggests a low level of forager fidelity to a single plant species. Investigation of colours of corollas in visible light by reflectance spectrophotometry and in long-wave (360 nm) ultraviolet light by photography revealed distinct reflectance spectra for visible light, but no ultraviolet reflectance. A wide range of sugar concentrations in nectars from the six species of Pedicularis was detected by refractometry. Chromatographic analysis of nectars indicated fructose and sucrose in nectars of four species, with P. lanata and P. langsdorffii having additional glucose and raffinose, or glucose and rhamnose, respectively. Nectar was abundant in all species except P. labradorica. A comparison of lengths of nectariferous tubes of corollas, lengths of tongues (prementum plus glossa) of pollinators, behaviour of pollinators, and diversity of species of pollinators on each species of Pedicularis indicated that adaptive behaviour of pollinators was related to the length of tongues of pollinators. It is suggested that interactions between floral mechanisms and pollinating insects probably contributed substantially to the present diversity of floral form in species of Pedicularis in North America.
Williams and Batzlli (1982) studied five species of Pedicularis (P. lanata [kanei], P. langsdorffii, P. sudetica, P. capitata, and P. lapponica) that are common near Atkasook, Alaska, and rely on bumblebees for pollination. In 1975 and 1976, bumblebees were not abundant, and although most flowers were pollinated (60–95%, depending on year and species), only 20–50% of the ovules in pollinated flowers developed. All species shared characteristics that favoured outcrossing: all were protogynous, all required an insect vector for pollination and all, except a late-flowering species, produced more seeds when outcrossed than when inbred. Despite a short growing season, one species bloomed earlier than the rest and one bloomed later than the rest. The early blooming species (P. (kanei) lanata) had the largest shoots and produced many seeds even though nectar production and pollination success (seeds per ovule) were low. The late blooming species (P. lapponica) had the smallest shoots and produced few seeds even though pollination success was high. Of the species blooming in mid-season, P. capitata had few flowers, and thus few seeds per shoot, even though nectar production and pollination success were high; P. langsdorffii had large numbers of ovules, high pollination success, and the largest number of seeds per shoot; and P. sudetica had intermediate number of ovules but low pollination success and low numbers of seeds per shoot when growing in isolated patches. Species that had greater leaf weight per shoot (more photosynthetic material) produced more seeds, so that their total weight seed produced per shoot was larger. Analysis of dispersion patterns indicated that each species reached peak abundance in different habitats and that local spatial overlap (1-m2 quadrats) was slight. The authors reported that these patterns could be interpreted as responses to competitive interactions, but sexual reproduction was less successful in relatively pure stands of a single species than in mixed stands of several species. Apparently, plants in mixed stands benefited from attraction of bees because of the greater density of flowers. Once attracted, individual bees tended to concentrate their foraging on a single species of plant.
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..