Euphrasia arctica
Bot. Tidsskr. 4: 47. 1870.
Stems simple or branched, to 25(–35) cm; branches 1–5(or 6) pairs, from proximal, middle, or distal cauline nodes; cauline internode lengths 2–4 times subtending leaves. Leaves: blade usually broadly ovate, 3–16 mm, margins serrate, teeth 1–6 pairs, apices acute. Inflorescences beginning at node 3–5; bracts green or purplish adaxially, broader than leaves, broadly ovate or deltate, length not more than 2 times width, (4–)5–9(–11) mm, surfaces glabrous or setose and hairs eglandular, sometimes pubescent and hairs glandular, stalks 1- or 2-celled, 0.1–0.2 mm, teeth 3–6 pairs, as long as or much longer than wide, apices acute to acuminate. Flowers: corolla white, sometimes lilac, adaxial lip lilac, 6–11(–13) mm, abaxial lip exceeding adaxial. Capsules oblong to elliptic or obovate, 4.5–8 mm, apex truncate to retuse.
Distribution
n North America, Europe, Atlantic Islands (Iceland).
Discussion
Subspecies 5 (2 in the flora).
The other three subspecies of Euphrasia arctica occur in Europe (P. F. Yeo 1978).
Selected References
None.
Key
1 | Stem bases flexuous or decumbent; branches 1 or 2(–5) pairs, usually flexuous; bract surfaces glabrous or hairy, hairs eglandular bristles, teeth not much longer than wide; corollas 7–11(–13) mm. | Euphrasia arctica subsp. arctica |
1 | Stem bases erect; branches 1–5(or 6) pairs, usually straight; bract surfaces hairy, hairs glandular and eglandular bristles, teeth much longer than wide; corollas 6–8(–10) mm. | Euphrasia arctica subsp. borealis |