Epilobium anagallidifolium |
Epilobium densum |
|
|---|---|---|
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alpine willow-herb, pimpernel willow-herb, épilobe à feuilles de mouron |
downy willowherb, épilobe dressé |
|
| Habit | Herbs with spreading thin, small-leafed epigeous soboles to 5 cm. | Herbs with threadlike, sparsely leaved epigeous stolons terminating with compact fleshy turions 4–8 × 3–4 mm. |
| 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. |
erect, simple or loosely clustered, terete, 15–95 cm, often well branched distally, densely villous throughout, sometimes mixed glandular puberulent distally, decurrent lines absent. |
| 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. |
opposite proximally, alternate and often fasciculate distally, subsessile; blade oblong-lanceolate to sublinear, 2–4.5 × 0.3–0.9 cm, ± exceeding internodes, base cuneate, margins entire or denticulate, 3–6 inconspicuous teeth per side, sometimes revolute, veins apparent on abaxial side, 3–5 per side, apex acute, surfaces villous, especially distally; bracts somewhat reduced. |
| Inflorescences | nodding in bud, later suberect, few-flowered racemes, subglabrous to sparsely strigillose and/or glandular puberulent. |
erect racemes, branched or not, densely villous, sometimes mixed 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. |
erect; buds 2.5–5 × 1.5–1.5 mm; pedicel 3–8 mm; floral tube 1–1.8 ×1–2 mm, ring of spreading hairs at mouth inside; sepals 2–4.5 × 1–1.3 mm, abaxial surface villous and glandular puberulent; petals light to dark pink, obcordate, 4–6 × 2–3 mm, apical notch 1–1.5 mm; filaments pink, those of longer stamens 2–3.5 mm, those of shorter ones 1–2 mm; anthers cream, 0.5–0.8 × 0.4–0.6 mm; ovary 12–20 mm, densely villous, often mixed glandular puberulent; style cream, 2–3.5 mm, stigma narrowly clavate, entire, 1–1.6 × 0.5–1 mm, surrounded by anthers. |
| Capsules | slender, often reddish purple, 17–40(–55) mm, surfaces subglabrous or with scattered hairs; pedicel 5–35(–68) mm. |
35–68 mm, short-beaked, surfaces densely villous, sometimes mixed glandular puberulent; pedicel 5–15 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. |
narrowly fusiform to narrowly obovoid, 1.5–2 × 0.5–0.6 mm, chalazal collar inconspicuous, 0.1 mm, surface low papillose; coma persistent, dingy white, 6–8 mm. |
| 2n | = 36. |
= 36. |
Epilobium anagallidifolium |
Epilobium densum |
|
| Phenology | Flowering Jun–Sep. | Flowering Jul–Sep. |
| Habitat | Moist flats, stream banks, subarctic coastal marsh edges, high montane and alpine meadows and seeps. | Sphagnum and peat bogs, marshes, seeps, damp pastures. |
| Elevation | 0–4500 m. [0–14800 ft.] | 0–600 m. [0–2000 ft.] |
| Distribution |
AK; CA; CO; ID; ME; MT; NH; NV; OR; UT; WA; WY; AB; BC; NL; NT; NU; QC; YT; Greenland; Eurasia
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CT; IA; IL; IN; MA; MD; ME; MI; MN; NH; NJ; NY; OH; PA; RI; VA; VT; WI; NB; NS; ON; PE; QC
|
| 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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Epilobium densum is relatively uncommon but widely distributed within the Great Lakes-St. Lawrence River region in boggy or marshy areas. Within that region, it sometimes grows in close proximity with E. leptophyllum and E. palustre; it is densely pubescent like E. leptophyllum, and although the type of hairs differs markedly on the two species, they sometimes are found mixed on herbarium sheets. Because it is less pubescent, E. palustre is rarely mixed or confused with E. densum. Hybrids among these species occur but are uncommon and generally marked by slightly to moderately reduced seed fertility. M. L. Fernald (1944d), among others, argued that names published in the Catalogus by Muhlenberg were not validly published. In the case of Epilobium strictum, K. Sprengel considered that Muhlenberg provided enough of a description (upright, soft) to validate the name in 1825. However, Rafinesque had validly published the name E. densum for the same taxon in 1814. Epilobium molle Torrey is an illegitimate name that pertains here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
| Parent taxa | ||
| Sibling taxa | ||
| Synonyms | E. alpinum, E. pseudoscaposum | E. strictum |
| Name authority | Lamarck in J. Lamarck et al.: Encycl. 2: 376. (1786) | Rafinesque: Précis Découv. Somiol. 42. (1814) |
| Source | FNA vol. 10. | FNA vol. 10. |
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