Flora of the Canadian Arctic Archipelago
English: Moss heather,
French: Casiope hypnoïde.
Ericaceae, Bilberry family.
Published in Proc. Wash. Acad. Sci. 3: 575. 1901.
Type: "Andromeda foliis aciformibus confertis" in Linnaeus (1737), Flora Lapponica t. 1, f. 3, lectotype, selected by Stone and Stone, in Cafferty and Jarvis, Taxon 51: 752. 2002.
Sweden: Torne Lappmark, Jukkasjärvi s:n., Vassitjåkko, 17.07.1948, leg. Melderis. Epitype: BM.
Synonymy. Andromeda hypnoides L., Sp. Pl. 393. 1753.
Cassiope hypnoides (L.) D. Don, Edinburgh New Philos. J. 17: 158. 1834.
Vegetative morphology. Plants 1–5 cm high; shrubs (that are moss-like); dwarf shrubs. Horizontal stems at ground level, branching extensively to shape plant habit as mats (moss-like). Aerial stems ascending and prostrate (usually). Leaves present; distributed along the stems; alternate (crowded, loosely imbricate, soft); dying annually and non-persistent. Petioles absent. Leaf blade bases truncate. Blades 1.2–2.5 mm long, 0.2–0.4 mm wide, appressed to the stem and spreading, linear, flat, appearing single-veined. Blade adaxial surface glabrous. Blade abaxial surface glabrous. Blade margins entire and serrulate (teeth minute; just visible at 40×), glabrous; apices acuminate (prow-shaped).
Reproductive morphology. Flowering stems two or more per plant. Flowers solitary, or in inflorescences (at the tips of branches, technically flowering-stems, but pedicel-like). Inflorescences racemose (if applicable); terminal. Pedicels present. Bract leaves 5–12 mm long. Flowers small. Sepals conventional; 5; free; 0.9–1.1 mm long; 1.8–2.2 mm wide; red (with wine-red margins), or black (or red black centres); petaloid. Calyx without sessile glands; glabrous. Petals conventional; fused; 5; white; 3.5–4 mm long; not spurred. Corolla tubular, or urceolate; 5-lobed. Stamens 8(–10). Anthers reddish, becoming yellow. Anthers opening with a terminal pore. Anthers 0.3–0.5 mm long (two tiny horns to 0.8 mm long). Nectaries present (as a ring between ovary and anthers). Ovary inferior; carpels 5; syncarpous. Ovaries sub-globose; glabrous. Styles 1. Placentation axile. Ovules per ovary numerous. Fruit stalked; stalk 8–12 mm long; with calyx persisting; dry; a capsule; spherical; brown, or red (folded sepals); 1.5–2 mm long; 1.5–2 mm wide (to 2.5 mm wide, when open); surface appearing veinless; not distinctly flattened; dehiscent; splitting to the base into separate segments; teeth 5. Seeds numerous; 0.4–0.5 mm long; yellowish.
Chromosome information. 2n = 32, or 48.
2n (4x) = 32. Jørgensen et al. (1958, Greenland); Löve and Löve (1961d, northern Europe; 1966b, northeastern USA); Sorsa (1963b, Finland);
2n (6x) = 48. Hagerup (1928).
Ploidy levels recorded 4x and 6x.
Ecology and habitat. Substrates: snow patches, along streams; imperfectly drained moist areas; rocks, gravel, sand. In sheltered rocky places, especially along brooks and lakeshores where the snow remains into late summer (Porsild 1957). On rocks at waterfall (CAN 88657); sheltered south-facing slopes (CAN 342818); sunny, sandy bank (CAN 466291).
North American distribution. Nunavut Islands, continental Nunavut, northern Quebec, Labrador. Range in the Canadian Arctic Archipelago limited. Low Arctic and alpine. Arctic islands: Baffin (Salisbury Island).
Northern hemisphere distribution. Amphi-Atlantic. Northern Iceland, Northern Fennoscandian, KaninPechora, Svalbard Franz Joseph Land, Polar Ural Novaya Zemlya, YamalGydan, Central Canada, Labrador Hudson Bay, West Greenland, East Greenland.
General notes. The genus Harrimanella, as a genus separate from Cassiope, was erected by Coville [Proc. Wash. Acad. Sci. 3: 569.1901].
Kron et al. (1999) presented good cladistic evidence that Harrimanella should be separated from Cassiope. They belong in two fairly different branches of Ericaceae.
Illustrations. • Habitat: Dorset. Plants forming a "moss heather" in the shelter and extra moisture around a rock. Nunavut, Baffin Island, Cape Dorset. 3 August, 2005. Aiken. No voucher. • Rock habitat. Plants at the position of the scale bar growing in a rock crevice at the side of a waterfall. Nunavut, Baffin Island, Soper River Valley, Cascade River. Aiken 2002. No voucher. • Close-up of previous picture. Plants creeping up the rock face with small pink buds. Nunavut, Baffin Island, Soper River Valley, Cascade River. Aiken 2002. Scale bar in cm. • Close-up of leaves. Note moss-like leaves. This portion came from an etiolated plant that had been growing under a rock. • Habitat. Flowering plants of moss heather with small moss-like leaves and tiny white flowers with fused petals and vivid red short, sepals. Growing with plants of white heather that has much larger leaves. Nunavut, Baffin Island, Iqaluit. 4 July, 2002. Aiken 02–014. CAN. Scale bar in cm. • Close-up of bud. Centre, flower bud with free vivid red sepals that appear large relative to the bud. Petals are pink-tipped in bud. Nunavut, Baffin Island, Iqaluit. Aiken 02–014. CAN. • Contrasting Cassiope and Harrimanella flowers. Note the similarity of the flower structure. Left, Cassiope; right, Harrimanella. Both flowers have fused petals, 10 anthers that open by terminal pores and have horns on the opposite ends. Aiken and LeBlanc 2004. • Surface view of flower. Flower with two whorls of five anthers clustered around the gynoecium with whitish petals and pinkish sepals seen through the petals. Aiken 02–014. CAN. • Plants with capsules. Plants with capsules, growing over a rock with Arctous alpina. Nunavut, Apex Hill. 19 August, 2006. Aiken. No voucher. • Previous season's capsule. Capsule that has split at 5 positions to release seeds. The tops of the capsule segments are attached to the central axis, the sepals are spreading at the base. Nunavut, Baffin Island, Iqaluit. 6 July, 2004. Aiken and LeBlanc 04–018. CAN 586491. • 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..