Epilobium anagallidifolium

Lamarck in J. Lamarck et al.

Encycl. 2: 376. 1786.

Common names: Alpine or pimpernel willowherb épilobe à feuilles de mouron
Synonyms: Epilobium alpinum Linnaeus E. pseudoscaposum Haussknecht
Treatment appears in FNA Volume 10.
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Herbs with spreading thin, small-leafed epigeous soboles to 5 cm. Stems many, ascending, often sigmoidally bent, nod­ding distally, later erect, clumped or mat-forming, terete, 3–20 (–25) cm, simple, subglabrous, sometimes with faint raised strigillose lines decurrent from margins of petioles, rarely mixed strigillose and sparsely glandular puber­ulent distally. Leaves opposite and crowded proximal to inflorescence, alternate distally, petioles 1–6 mm, rarely subsessile distally; blade spatulate to oblong proxi­mally, elliptic to narrowly lanceolate or sublinear distally, (0.5–) 0.8–2.5 × 0.3–1 cm, base attenuate to cuneate, margins subentire proximally, sparsely denticulate distally with 2–5 low teeth per side, veins obscure, 2–4 per side, apex obtuse or rounded proximally to subacute distally, surfaces subglabrous; bracts reduced, usually much narrower. Inflorescences nodding in bud, later suberect, few-flowered racemes, subglabrous to sparsely strigillose and/or glandular puberulent. Flowers sub­erect; buds 2–5 × 1–2 mm; pedicel 1–6 (–15) mm; floral-tube 0.6–1.2 × 0.8–1.8 mm, slightly raised subglabrous ring at mouth inside; sepals green to reddish purple, 1.5–5 × 0.6–1.5 mm, abaxial surface subglabrous to sparsely glandular; petals usually pink to rose-purple, rarely white, narrowly obcordate, (1.7–) 2.5–6.5 (–8) × 1.6–3.5 mm, apical notch 0.5–1.2 mm; filaments cream to light pink, those of longer stamens 1.4–3.2 mm, those of shorter ones 0.7–2 mm; anthers 0.3–0.6 × 0.2–0.4 mm; ovary often reddish purple, 6–20 mm, subgla­brous or sparsely strigillose and glandular puberulent; style white, 1.2–2.5 mm, glabrous, stigma broadly clavate to subcapitate, entire, 0.9–1.5 × 0.4–0.7 mm, surrounded by longer anthers. Capsules slender, often reddish purple, 17–40 (–55) mm, surfaces subglabrous or with scattered hairs; pedicel 5–35 (–68) mm. Seeds narrowly obovoid, 0.7–1.4 × 0.3–0.5 mm, inconspicuous chalazal collar 0.1–0.2 mm wide, light-brown, surface reticulate (smooth); coma persistent, dull white, 2–4 mm. 2n = 36.


Phenology: Flowering Jun–Sep.
Habitat: Moist flats, stream banks, subarctic coastal marsh edges, high montane and alpine meadows and seeps.
Elevation: 0–4500 m.

Distribution

Greenland, Alta., B.C., Nfld. and Labr., N.W.T., Nunavut, Que., Yukon, Alaska, Calif., Colo., Idaho, Maine, Mont., Nev., N.H., Oreg., Utah, Wash., Wyo., Eurasia

Discussion

Epilobium anagallidifolium is widely but sparsely distributed in high montane-alpine and subarctic Eurasia, including Europe, Russia, China, and Japan.

Epilobium anagallidifolium usually forms low clumps or mats, with stems nodding in bud and usually subglabrous below the inflorescence. Many collections of E. anagallidifolium from eastern Canada and Greenland tend to be unusually tall (to 25 cm) and robust for the species, with somewhat larger, thicker leaves, and longer pedicels (to 60 mm). Similarly large and robust specimens occur scattered in Yukon and Washington, and may result from occasional hybridization and introgression with sympatric species such as E. hornemannii or E. lactiflorum, which also have the CC chromosomal arrangement. In an analysis of Fennoscandian populations of the Alpinae group, I. Kytövuori (1972) found a similar pattern of mostly smaller, sigmoidal plants of E. anagallidifolium with a small proportion of larger ones, and he also suggested the possibility of hybridization and/or introgression.

Plants of Epilobium anagallidifolium, and indeed of the whole Alpinae group, from Haida Gwaii (the Queen Charlotte Islands) of British Columbia (J. A. Calder and R. L. Taylor 1968), are particularly distinctive com­pared to those on the mainland, and difficult to interpret. The observed differences may be the result of hybridization with other sympatric species or a response to unique ecological conditions on the islands, reinforced by relative isolation from mainland British Columbia.

The Linnaean name Epilobium alpinum has long been a source of nomenclatural confusion and instability, since it circumscribed at least four distinct species, especially E. anagallidifolium. A proposal by P. C. Hoch et al. (1995) to permanently reject the name E. alpinum Linnaeus was approved.

Selected References

None.

Lower Taxa

None.

"narrower" is not a number.

subglabrous +  and sparsely glandular +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
episepalous +
subequal +  and longer +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
rounded +  and proximally subacute +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Peter C. Hoch +
Lamarck in J. Lamarck et al. +
attenuate +  and cuneate +
indehiscent +  and loculicidal +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
toothed +  and entire +
elliptic +  and narrowly lanceolate or sublinear +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
reduced +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
recurved +  and erect +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
sessile +  and pedicellate +
4 cm40 mm <br />0.04 m <br /> (5.5 cm55 mm <br />0.055 m <br />) +
reddish purple +
curved +  and straight +
narrowly subcylindric +  and narrowly clavate +
1.7 cm17 mm <br />0.017 m <br /> (4 cm40 mm <br />0.04 m <br />) +
sessile +  and pedicellate +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
persistent +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Alpine or pimpernel willowherb +  and épilobe à feuilles de mouron +
Greenland +, Alta. +, B.C. +, Nfld. and Labr. +, N.W.T. +, Nunavut +, Que. +, Yukon +, Alaska +, Calif. +, Colo. +, Idaho +, Maine +, Mont. +, Nev. +, N.H. +, Oreg. +, Utah +, Wash. +, Wyo. +  and Eurasia +
0–4500 m. +
basifixed +  and versatile +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
0.8mm +  and 1.8mm +
actinomorphic +
sessile +  and pedicellate +
curved +  and straight +
4-angled +, terete +, narrowly cylindrical +  and fusiform or rarely narrowly ellipsoidal +
slender +
Moist flats, stream banks, subarctic coastal marsh edges, high montane and alpine meadows and seeps. +
perennial +  and annual +
suffrutescent +
suberect +  and nodding +
alternate +, crowded +  and opposite +
deciduous +
raised +  and faint +
strigillose +
decurrent +
denticulate +  and subentire +
reddish purple +
puberulent +  and strigillose +
0.6 cm6 mm <br />0.006 m <br /> (2 cm20 mm <br />0.02 m <br />) +
numerous +  and 1 +
multicellular +
3.5 cm35 mm <br />0.035 m <br /> (6.8 cm68 mm <br />0.068 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.65 cm6.5 mm <br />0.0065 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
white +, usually pink +  and rose-purple +
2.5mm +  and 6.5mm +
obcordate +
0.16 cm1.6 mm <br />0.0016 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Flowering Jun–Sep. +
puberulent +, subglabrous +  and sparsely strigillose +
inflated +
subglabrous +
basal +  and cauline +
clavate +  and globose +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
sculptured +  and smooth +
obovoid +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
green +  and reddish purple +
deciduous +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
parenchymatous +
parietal +, axile +  and placentation +
unequal +
aquatic +, amphibious +  and terrestrial +
0 cm0 mm <br />0 m <br /> (5 cm50 mm <br />0.05 m <br />) +
cream +  and light pink +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
2 times as many as sepals +
mixed +  and clumped +
20 cm200 mm <br />0.2 m <br /> (25 cm250 mm <br />0.25 m <br />) +
mat-forming +
prostrate +  and decumbent +
erect +  and ascending +
strigillose +  and subglabrous +
exfoliating +
terete +  and bent +
3 cm30 mm <br />0.03 m <br /> (20 cm200 mm <br />0.2 m <br />) +
not woody +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
clavate to subcapitate +  and clavate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
subsessile +  and petiolate +
intrapetiolar +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
aquatic +, amphibious +  and terrestrial +
with scattered hairs +  and subglabrous +
papillose +  and finely reticulate +
constricted +
Epilobium alpinum +  and E. pseudoscaposum +
Epilobium anagallidifolium +
Epilobium sect. Epilobium +
species +
3(-5)-aperturate +