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

Euphrasia disjuncta Fernald and Wiegand

Scrophulariaceae, Fernweed family.

Published in Rhodora 17: 190. 1915.

Type: Canada: Newfoundland, Grand Falls, Valley of Exploits River, 12.08.1911, leg. M.L. Fernald, K.M. Wiegand and H.T. Darlington 6169. Holotype. GH.

Vegetative morphology. Plants 3.5–8(–10) cm high (plants to 20 cm high and much branched in Newfoundland); annual herbs; not caespitose. Taproot present. Ground level or underground stems absent. Aerial stems erect. Aerial stem trichomes present; retrorse (more or less). Leaves distributed along the stems; opposite; dying annually and non-persistent. Petioles absent. Leaf blade bases attenuate (sometimes almost petiolate). Blades 2–5(–8) mm long (other than the tiny cotyledon leaves that sometimes persist), 4–8 mm wide, spreading, obovate or spatulate (floral leaves associated with each flower, lower floral leaves usually with spreading basal teeth), flat, veins palmate. Blade adaxial surface glabrous (usually light green the cauline leaves 1–6 pairs of obtuse to acute (rarely aristate) teeth, the upper ones usually broadly ovate). Blade abaxial surface without sessile glands or glandular hairs (on the blade surfaces), glabrous. Blades lobed. Leaf primary lobes ovate-lanceolate to obovate-lanceolate, all lobes pointing forwards. Blade margins crenate, with glandular hairs, with teeth toward the apex; apices obtuse, or rounded (blunt to somewhat acute).

Reproductive morphology. Flowering stems circular or oval in cross section. Flowering stems with leaves (lowest flower at node 3–9). Flowering stems hairy. Flowering stems pilose. Flowering stem hairs simple; shorter than the diameter of the flowering stem; white or translucent; glandular hairs absent. Inflorescences spicate; elongating as the fruit matures (slightly). Pedicels absent. Flowers per inflorescence (2–)3–5; described as "large" flowered; bilaterally symmetrical (zygomorphic). Sepals conventional; 4; fused; 3.5–4 mm wide; green. Calyx tubular; 4-lobed; hairy (with setose, stiffish trichomes, particularly on the margins). Calyx hairs non-glandular; white or translucent. Calyx margins ciliate (hairs "setose" c.f. stiffish cilia). Calyx teeth equal or nearly so; without or with few glandular verrucae; 1.4–1.6 mm long. Petals conventional; fused; 5; white, or pink, or purple (deep lilac with a "yellow eye", the upper lip tinged with purple, slightly 2-lobed, the lower lip white with purple lines); with contrasting markings; 4.5–5 mm long. Corolla bilabiate; 4-lobed (each lobe notched). Stamens 4; stamen filaments markedly unequal in length (didynamous); free of the corolla. Anthers 0.8–1 mm long (anthers with parallel loculi, spurred, one loculus with a longer spur than the other). Ovary superior; carpels 2; syncarpous. Ovaries ovate, or oblong; hairy (especially at the apex). Ovary hairs white; spreading; straight. Styles 1; 4–4.5 mm long; straight. Stigmas per ovary 1. Placentation axile. Ovules per ovary numerous. Fruit sessile; with calyx persisting; dry; a capsule; oblong (usually 2–3 times as long as wide, truncate to emarginate); brown; 4–8 mm long; hairy; surface appearing veinless; not distinctly flattened; dehiscent; splitting to the base into separate segments. Seeds numerous; 1.8–2 mm long; brown, or yellowish; surfaces smooth (but with fine ridges seen in a clear coating at 40×).

Ecology and habitat. Substrates: along streams, slopes; imperfectly drained moist areas, dry; gravel, silt, clay, till, moss; with high organic content, peat. Uncommon on damp grassy sites, Baffin Island, Winton Bay 63°20'N, 64°45'W (CAN 284049).

North American distribution. Nunavut Islands, northern Quebec, Newfoundland. Range in the Canadian Arctic Archipelago limited. Rare. Low Arctic, alpine. Arctic islands: Baffin.

Northern hemisphere distribution. Northeastern Canada.

General notes. Euphrasia disjuncta Fernald and Wiegand [Rhodora 17: 190. 1915] is restricted to northeastern North America (with a parallel species, E. subarctica Raup, in northwestern North America), typified from Newfoundland [Canada: western Newfoundland, Grand Falls, Valley of Exploits River, 12.08.1911, leg. M.L. Fernald, K.M. Wiegand and H.T. Darlington 6169 (GH) holotype], and widely distributed. The major parts of the range mapped by Porsild and Cody (1980) belong to this species. It is characterised by flowering at high nodes, small to intermediate, white-lilac flowers, leaves crenate, with many simple hairs but with an admixture of long multicellular glandular hairs, the calyx is fairly hairy. The type specimens have these characters, but in the same population (type sheet) are plants, with and without, glandular hairs. A syntype from Blanc Sablon Quebec (31.07.1910, leg. Fernald and Wiegand) has the same characters.

Polunin (1940) recognised var. minutissima Polunin, stating it includes specimens from Wakeham Bay collected in 1927 by Dr. Malte and distributed as E. oakesii var. Wettstein, which even if they had rather blunt bracts, suggestive of the latter species, were clearly seen to belong to the E. arctica series on boiling out a flower, when the previously shrivelled corolla showed itself to be about 5 mm long and to have the upper lip quite deeply lobed. Polunin (1940) noted that his variety is apparently limited to the eastern half of the extreme south, where it is quite general in the mainland regions of Quebec and northernmost Labrador, and also occurs in Baffin northwards to near the Arctic Circle. Polunin (1940) also noted that the species often occur in great numbers, but is so diminutive that it has to be looked for to be found. It flowers and fruits abundantly except in places where the growing season is shortened by the late melting of the snow; here, being a summer annual, it is unable to persist.

Elven et al. (2003) noted that this taxon is characterised by flowers born at middle to high nodes, small to intermediate-sized, white-lilac flowers, leaves crenate, with many simple hairs mixed with long multicellular glandular hairs, and a fairly hairy calyx. The type specimens confirm with these characters, but in the same population (type sheet) are plants both with and without glandular hairs. A syntype from Blanc Sablon (31.07.1910, leg. Fernald and Wiegand) has the same characters.

Elven (personal communication, 2005) noted that Hultén (1968a, 1968b) tentatively synonymised the western E. subarctica and the eastern E. disjuncta under the latter name. The arctic Alaskan plants belong to 'subarctica', the arctic northeastern Canadian plants to 'disjuncta'. Morphologically, E. subarctica is different from both E. disjuncta and another eastern species, E. hudsoniana. At anthesis E. subarctica is very prolonged with first flowers at high nodes, very small yellowish flowers (white-lilac ones in E. disjuncta), and a dominance in the indumentum of long multicellular glandular hairs. The plants from Northwest Territory are less glandular than those from further west. The type originates from the more eastern parts of the range, but Raup (in comment with the description) identified E. subarctica with the Fairbanks (Alaska) plants, i.e., with the western entity. Therefore, synonymizing these two species is not recommended.

Illustrations. • 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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