Flora of the Canadian Arctic Archipelago

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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

Polemonium boreale Adams

English: Jacob's Ladder.

Polemoniaceae, Polemonium family.

Published in Mém. Soc. Imp. Naturalistes Moscou 5: 92. 1817.

Type: Described from northern Siberia: Yakutia, lower Lena River.

Synonymy. Polemonium hyperboreum Tolm., Feddes Repert. 23, 18–25: 273. 1927.

Polemonium pulcherrimum Hooker subsp. hyperboreum (Tolm.) Á. Löve and D. Löve, Bot. Not. 128: 517. 1975.

Polemonium humile Willd. ex Roem. and Schult., Syst. Veg. 4: 792. 1819. Non Salisb., Prodr. Stirp. Chap. Allerton 125. 1796.

Polemonium boreale Adams subsp. humile (Willd. ex Roem. and Schult.) Á. Löve and D. Löve, Bot. Not. 128: 517. 1976.

Polemonium hyperboreum Tolm., Repert. Spec. Nov. Regni Veg. 23: 273. 1927.

Polemonium pulcherrimum Hook. subsp. hyperboreum (Tolm.) Á. Löve and D. Löve, Bot. Not. 128: 517. 1976.

Vegetative morphology. Plants 10–15(–20) cm high; perennial herbs; glandular viscid. Only fibrous roots present. Ground level or underground stems horizontal, or vertical (branching); rhizomatous; elongate; 0.5–2 mm wide. Caudex present (much branching). Aerial stems erect, or ascending. Aerial stem trichomes spreading, or erect. Leaves mainly basal; alternate; dying annually and non-persistent. Stipules absent (base of petiole swollen with a pulvinus area that may be purple). Petioles 0.5–2.5(–3.5) mm long; winged (at the base); hairy; woolly. Petiole hairs shorter than the diameter of the petiole; spreading, or erect; floccose; smooth. Leaf blades compound. Blades 20–55 mm long, 6–16(–18) mm wide, spreading, appearing single-veined. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins entire, with glandular hairs; apices acute. Leaflet arrangement pinnate. Leaflets (4–)6–10(–12); 4–12 mm long; 1.5–4 mm wide; elliptic; veins inconspicuous.

Reproductive morphology. Flowering stems with leaves. Flowering stems hairy. Flowering stems woolly. Flowering stem hairs white or translucent; glandular hairs present. Inflorescences cymose; dense; globose or sub-globose; 2–4 cm long; 20–40 mm wide. Pedicels present (but short); with glandular hairs. Flowers per inflorescence 3–7(–9); medium-sized, or large; radially symmetrical (actinomorphic). Sepals conventional; 5; fused; 5–7 mm wide; green. Calyx tubular; 5-lobed; hairy. Calyx hairs woolly; glandular; white or translucent. Petals conventional; fused; 5; purple, or blue (on the lobes), or yellow (on the tubular base); with contrasting markings (centre of the flower near the throat is yellow); 15–18 mm long. Corolla rotate; 5-lobed (convolute in bud). Stamens 5 (alternate with the corolla lobes); stamen filaments glabrous; fused to the corolla (and attached at different levels). Anthers yellow; short-cylindrical; 2.8–3.2 mm long. Nectaries present (as a disc around the base of the ovary). Ovary superior; carpels 3; syncarpous. Ovaries ovate, or sub-globose; glabrous. Styles 1; (7–)8–10 mm long; straight. Stigmas per ovary 3. Stigma lobes 1.4–1.6 mm long. Placentation axile. Ovules per ovary numerous. Fruit sessile; stalk 2–5 mm long; with calyx persisting; dry; a capsule; ovoid; yellowish; 4.8–5.2 mm long; glabrous; surface venation ribbed; not distinctly flattened; dehiscent; splitting to the base into separate segments; teeth 3. Seeds numerous; 0.1–0.2 mm long; black (dark brown); surfaces spinose.

Chromosome information. 2n = 18.

2n =18. Flovik (1940); Sokolovskaya and Strelkova (1960, northern Russia); Zhukova (1965b, Wrangel Island; 1966, northeastern Asia); Laane (1966, 1969a, northern Norway); Johnson and Packer (1968, northwestern Alaska); Zhukova and Petrovsky (1976, western Chukotka; 1987b, north and northeastern Asia); Krogulevich (1976a, northern Siberia, as P. boreale and P. hyperboreum; 1984 Siberia); Dawe and Murray, in Löve (1979, central Alaska, for subsp. villosissimum); Petrovsky and Zhukova (1981, Wrangel Island); Lavrenko et al. (1989, northern Russia). Several more southern counts.

Ploidy levels recorded 2x.

Ecology and habitat. Substrates: river terraces, slopes, flood plains; dry, moderately well-drained areas (very often on scree slopes and bird manured outcrops); gravel, sand (disturbed sites); with low organic content; calcareous, or nitrophilous. Calcareous, gravelly places, often near animal burrows (Porsild 1957); grassy places below sea-gull cliff (CAN 128075); open vegetation on calcareous stony, frost-heaved clay (CAN 220042); exposed saxifrage slope (CAN 535565); Dryas solifluction slope (CAN 535548); Salix slope (CAN 535599); boulder ridges and stream bed (CAN 220043).

North American distribution. Alaska, Yukon, Northwest Territories Islands, continental Northwest Territories, Nunavut Islands. Range in the Canadian Arctic Archipelago limited. Uncommon. Low Arctic. Arctic islands: Parry islands (Prince Patrick and Eglinton), Banks.

Northern hemisphere distribution. Circumpolar (with large North Atlantic gaps). Northern Fennoscandian, Kanin–Pechora, Svalbard – Franz Joseph Land, Polar Ural – Novaya Zemlya, Yamal–Gydan, Taimyr – Severnaya Zemlya, Anabar–Olenyok, Kharaulakh, Yana–Kolyma, West Chukotka, Wrangel Island, South Chukotka, East Chukotka, West Alaska, North Alaska – Yukon, Central Canada, East Greenland.

General notes. Elven et al. (2003) noted that the 'hyperboreum' taxon is synonymised with P. boreale by Tzvelev [in Fl. Arct. URSS 8. 1980] but separated as a subsp. hyperboreum of P. pulcherrimum by Löve and Löve (1975) and as a separate species by Hultén (1968b).

The names 'hyperboreum' and 'humile' are synonyms of P. boreale (Petrovsky, personal communication, May 2000).

Illustrations. • Habitat. Plants with purple-blue flowers near the scale bar. The magenta-coloured flowers are Hedysarum boreale. N.W.T., Banks Island, Aulavik National Park, sand dunes beside the Thomsen River. 9 July, 1999. Aiken 99–037. CAN. Scale bar in cm. • Close-up of plants. Plants about 6 cm high growing in sand dunes. Note the pinnate compound leaves, the dense hairs on the calyx seen in the centre bud, the convolute buds, and petals that are overlapping in flower. N.W.T., Banks Island, Aulavik National Park, sand dunes beside the Thomsen River. 9 July, 1999. Aiken 99–037. CAN. Scale bar in cm. • Close-up of flowers. Note the darker guidelines on the purple-blue petals that are yellow at the base where they are fused into a tube. Note the yellow anthers, the filaments of which are attached to the petals. Aiken 99–037. CAN. • Close-up of flowers. Note the darker guidelines on the purple-blue petals that are yellow at the base where they are fused into a tube. Note the yellow anthers, the filaments of which are attached to the petals, and the stigma with three branches in the lower flower. Aiken 99–037. CAN. • Close-up of plant. Plant growing on a south-facing, dry and warm slope. Norway, Svalbard, Gipsvika. July, 1997. Photograph by R. Elven. • Close-up of flowers. Note left, a single flower and right, a three- to four-flowered inflorescence. Sepals are hairy and petals are fused at the base. Norway, Finnmark, Bugoynes. July, 1981. Photograph by R. Elven. • 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.

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