Euphrasia arctica

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.

Lower Taxa

Euphrasia arctica subsp. arctica, Euphrasia arctica subsp. borealis

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