Epilobium anagallidifolium
Epilobium suffruticosum
alpine willow-herb, pimpernel willow-herb, épilobe à feuilles de mouron
shrubby willowherb
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.
several–many, ascending to erect, terete, 10–25 cm, simple or well-branched, ± densely strigillose.
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.
often crowded, opposite and sometimes with fascicles of very small leaves at proximal nodes, subsessile or attenuate to broad petiole 0.5–1.5 mm, blade light grayish green, narrowly lanceolate to elliptic, 1–2.5 × 0.2–0.7 cm, often exceeding internodes, base cuneate to attenuate, margins entire or ± denticulate, 4–6 low teeth per side, lateral veins inconspicuous, apex blunt proximally to subacute, surfaces ± densely short-strigillose;
bracts not much reduced in size.
nodding in bud, later suberect, few-flowered racemes, subglabrous to sparsely strigillose and/or glandular puberulent.
erect racemes or panicles, ± densely strigillose.
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.
slightly nodding;
buds 4–8 × 1.5–3.5 mm, apiculate;
floral tube funnelform to obconic, 1.8–3 × 1.9–2.6 mm, ring of spreading hairs 1–2.5 mm from base inside;
sepals 3–6.5 × 1–2.6 mm, often apiculate, abaxial surface densely strigillose;
petals cream to light yellow, obcordate, 5–9.3 × 2–3.8 mm, slightly unequal with upper 2 longer, apical notch 1–2.3 mm;
filaments cream, slightly inflated at base, those of longer stamens 6–10 mm, those of shorter ones 4.5–8 mm;
anthers cream-yellow, 1.4–2.2 × 0.6–1.1 mm;
ovary 4–9 mm, densely white-canescent;
style declined below main plane of flower, cream, 7.8–14.5 mm, glabrous, stigma deeply 4-lobed, 0.8–1.2 × 1.8–2.8 mm, lobes spreading-recurved 0.9–1.2 mm, exserted beyond longer anthers, often prematurely exserted and protogynous.
slender, often reddish purple, 17–40(–55) mm, surfaces subglabrous or with scattered hairs;
pedicel 5–35(–68) mm.
often curved, fusiform-clavate, 10–30 mm, surfaces finely strigillose;
pedicel 4.5–13 mm.
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 obovoid to oblanceoloid, with constriction 0.7–1.3 mm from micropylar end, 2.1–3 × 0.7–1.1 mm, very inconspicuous chalazal collar, light brown, surface low-papillose;
coma easily detached, tawny, 7–9.5 mm, with unusually dense hairs.
= 36.
= 30.
Epilobium anagallidifolium
Epilobium suffruticosum
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 suffruticosum shares its unusual cream-yellow flower color only with E. luteum, a distantly related species in sect. Epilobium. Both species have relatively large flowers with 4-lobed stigmas and are visited quite intensively by bees and other insect pollinators. Nevertheless, these species differ dramatically in habit, leaves, seeds, and many other characters, do not overlap at all in distribution, and are never confused with one another; the similar floral features must have been derived independently.
The flowers of Epilobium suffruticosum are also slightly zygomorphic, which is relatively rare in the genus. In the field and on many herbarium specimens of E. suffruticosum, the stigmas are clearly exserted even before the flowers are fully open. The label for Raven 26451 (Wyoming, Park County, MO) notes: “protogynous; in late bloom, most flowers male-sterile.” Several flowers from this collection have undeveloped anthers, suggesting that the flowers are functionally pistillate. However, these plants are not sterile since they have apparently fertile capsules with fully developed seeds.
The distribution of Epilobium suffruticosum consists of two clusters of fairly common occurrence—in northwestern Wyoming around Yellowstone and Teton national parks, and in south-central Idaho mainly in the drainages of the Boise and Payette rivers—with more scattered collections in western Montana north to Flathead County, and a single collection to the south in Weber County, northern Utah. There are no obvious morphological discontinuities among these specimens, nor any obvious explanation for the gaps in distribution; it may be due to collecting bias. This species is commonly found on gravel/sand bars of cold montane streams and rivers, in a stable association despite the apparent ephemeral nature of these habitats. It would appear that the plants have deep, woody roots by which they anchor themselves; in the spring flood stages of these rivers, they must experience complete inundation and considerable scouring, yet persist, often in moderately large colonies.
The exact locality of the type collection (streams east of Wallawallah, plains of the Upper Columbia River, Oregon) is problematic, since the closest known localities are at least 250 km southeast of the town of Walla Walla, Washington. Whether this is a matter of the historical accuracy of the locality by Nuttall or of the local extinction of this species from a locality in eastern Oregon cannot be determined at present. A collection by Hayden in 1859 (Powder River, Wyoming) is far outside the range of E. suffruticosum and may have been mislabeled.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
PNW Herbaria, 
SW CO Wildflowers, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
