Euphrasia frigida Pugsley
Eyebright.
Scrophulariaceae, fernweed family.
J. Linn. Soc. London (Bot.) 48: 490. 1930.
E. arctica auct., non Lange ex Rostrup (1870–1871).
Vegetative morphology. Plants dwarf shrubs; 1–5(–15) cm high (Greenland, where stems are more likely to be branched); delicate, with opposite, sessile leaves and usually single unbranched stems. Taproot present. Caudex absent. Ground-level or under-ground stems not developed horizontally or vertically. Aerial stems erect; sparsely hairy, or densely hairy; stem hairs reflexed (more or less retrorse). Leaves distributed along the stems; opposite; not distinctly distichous (c.f. Bartsia); existing for a single season or less. Petioles absent. Leaf blade bases attenuate. Blades 3–8(–10) mm long; 3–8 mm wide. Blades spreading, or divaricate; ovate, or obovate; veins palmate. Blades adaxial surface glabrous (Baffin CAN 284049 = disjuncta), or scabrous (CAN 223788 and 156742 = frigida). Blades adaxial surface hairs simple, unbranched (if applicable); sparse, or moderately dense; white and translucent. Blades abaxial surface glabrous, or scabrous. Blades abaxial surface hairs sparse, or moderately dense. Blades abaxial surface pubescent. Blades abaxial surface hairs white, or translucent hairs; straight; spreading. Blade margins lobed. Blade margins glabrous, or scabrous. Leaf apices acute, or rounded.
Reproductive morphology. Flowering stems present. Flowering stems with leaves; hairy. Flowering stem hairs pilose (retrorse hairs); simple; white or translucent. Inflorescence spicate (flowers borne in the axils of leaves); diffuse; 1–2 cm long; 8–15 mm wide; not elongating as the fruit matures. Pedicels absent. Flowers per inflorescence (2–)3–5; medium-sized, 5–15 mm in diameter or length; zygomorphic. Perianth present. Calyx sepals 4; fused; 4.5–6.5 mm long. Calyx green; tubular; 4-lobed; hairy (with stiff scabrous trichomes). Calyx hairs white or translucent. Calyx margins ciliate. Petals fused; 5; white; with contrasting markings (purple or blue lines on each petal that is yellow at the base); 4–8 mm long. Stamens fused to the corolla. Anthers 0.6–0.8 mm long. Carpels syncarpous; 2. Ovaries oblong; hairy (towards the apex). Ovary hairs white, or translucent; spreading; straight. Styles 1; 4–8 mm long. Stigmas plate shaped. Placentation axile. Ovules numerous. Fruit sessile. Fruit with calyx persisting; dry; a capsule; oblong; dehiscent; splitting to the base into separate segments. Fruit 4.5–6 mm long; 2–3 mm wide; straw coloured; hairy (at apex); surface appearing veinless. Seeds numerous; 1.5–1.7 mm long; black, or brown; with surfaces ridged (with prominent white striate ridges).
Chromosome information. 2n = 44. - Sørensen and Westergaard in Löve and Löve (1948 Greenland); Löve and Löve (1956b Iceland); Jørgensen et al. (1958 Greenlandl). Ploidy levels recorded 4x.
Distribution. Northern hemisphere distribution: amphi-Atlantic; Greenland, Canada, Eurasia. Nunavut Islands, Northern Québec (and Labrador). Low arctic, or alpine. Range in the Canadian Arctic Archipelago limited. Rare. Arctic Islands: Baffin.
Ecology and habitat. Substrates: slopes, cliffs; imperfectly drained moist areas, or moderately well drained areas; with high organic content. Habitats: uncommon on damp grassy sites, Baffin Island, Winton Bay 63°20'N, 64°45'W (CAN 284049); Gull Cliffs opposite Pangnirtung (CAN 223788).
Notes. Possibly more than one taxon on Baffin Island:
Yeo (1972)
in the treatment of the genus Euphrasia for Flora Europaea indicated that
the genus is of annual (rarely perennial) hemiparasitic herbs. Flowers are
zygomorphic, in bracteate, terminal, spike-like racemes. Bracts (floral
leaves) are large and leaf-like; bracteoles are absent. Yeo(1972), stated
that most of the species are very variable and weakly differentiated, and they
hybridize readily; the taxonomy of the genus is therefore difficult. Populations
frequently occur in which one character falls outside the normal range of
variation and hybrids sometimes occur independently of the parents as well as
commonly with them.
Yeo (1972), stated that although with sufficient
experience it is possible to assign the great majority of populations to a
species, it is extremely difficult to provide rigidly diagnostic descriptions.
The most important taxonomic characters are length of internodes; node at which
the lowest flower is situations; number of branches; shape, size and indumentum
of leaves, size of corolla, shape, size, and indument of capsule. He did not
consider the presence or absence of eglandular or short glandular hair as very
important, although the he suggested the presence of absence of long glandular
hairs is.
Specimens from southern Baffin Island at CAN vary in the presence
and absence, and density of hairs when they are present, but none of the hairs
appear to be glandular which is characteristic of E. arctica (the name
used by Porsild (1957). The name E. frigida is tentatively used
following the suggestion of R. Elven. However, much confusion in the arctic taxa
still needs to be resolved (Elven 2001).
Illustrations. • Plants in habitat. Tiny annual plants between the markers, growing on a bare patch of ground in a wet meadow. Manitoba, Bird Cover, Aiken and Brysting 02–011. CAN. • Close-up of plants. Flowering annual plants about 3 cm high, growing on a relatively bare patch of ground in a wet meadow. Manitoba, Bird Cover, Aiken and Brysting 02–011. CAN. • Close-up of flower. Bilabiate flower less than 4 mm across, with two pale pinkish upper petals, two prominent anthers, yellow at the throat of the corolla, and three fused lower petals, each with a purple line. Manitoba, Bird Cover, Aiken and Brysting 02–011. CAN. • Close-up of flower. Centre, flowering bud wtht unequal, sepals that are prominently hairy. Left, post anthesis flower with long stigma lying against one of the anthers. Manitoba, Bird Cover, Aiken and Brysting 02–011. CAN. • Arctic Island Distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
