Genus Epilobium L.

Род 518 (2). ВЪРБОВКА — EPILOBIUM L.¹
L., Sp. PI. ed, 1 (1753) 347; Gen. PI. ed. 5 (1754) 164

Fam:   Onagraceae Juss.
Genus:   Epilobium L.
English Name: Willow-herb

Description:

Perennial herbaceous plants, most of them hygrophytes, often flowering in the first year, overwintering with shoots or rosettes located around the base of the stem. Stem glabrous, fibrous or glandular fibrous; Leaves simple, entire, consecutive or opposite, rarely in vertebrae. Flowers regular or slightly asymmetrical, axillary or in top bunches or classes. Hypanthus tubular or funnel-shaped or almost invisiible, after flowering drooping, sepals 4, straight, often colored. Petals 4, back ovoid or cut at the apex, pink or red, rarely whitish. Stamens 8, in two circles, 4 longer. The style is filamentous, straight or slightly curved: the stigma is bat-shaped or head-shaped, whole or deep 4-part. Ovary lower, 4-nested. The fruit is a linearly elongated, 4-edged, 4-nested pod-shaped box, cracking from top to bottom, between the ribs, with 4 parts, curved outwards. Seeds numerous, conversely ovate or spindle-shaped, smooth or with many warts and with a long kite of hairs. Insect-pollinated and self-pollinating, propagated by seeds propagated by wind and by vegetative shoots.

Remark. Our species grow singly or in groups, and only some of them form small coenoses. They appear as hygrophytic and mesophytic, but also as mesothermal and heliophytic plants. They occur in moist, primary ecotopes (near rivers, streams, springs), optimally developed. Most of them grow apophytically on secondary ecotopes (along roads, on embankments, ditches, coastal slopes, clearings, fires, abandoned fields, etc.). Smaller plants grow here and are gradually replaced by stronger species. They are characterized by high productivity of seeds, spreading quickly and far, and with their exceptional property of vegetative propagation by rhizome shoots.

Table for determination of the species 1 Leaves consecutive, dense. Blossoms more or less asymmetrical; sepals reddish, without or almost without hypanthium; the style bent at least before revealing the blossoms ……………………………………………………………………………...............................…………………... 2 1* Lower and middle leaves opposite or in vertebrae. The blossoms are correct; sepals greenish, with hypanthium; the style is very rarely curved ............................................................................................................................................................. 3 2   Leaves oblong-lanceolate, (3-) 4 - 15 cm long and 0.4 - 3.5 cm wide, below with convex, reticulately branched pale lateral veins. The seeds are smooth. Inflorescence long bunch ..................................................................... 1. - E. angustifolium L. 2* Leaves linear, 2 - 25 cm long, 1 - 3 mm wide, below with a clear midrib, lateral veins invisible. The seeds are gently warty. Inflorescence short loose bunch ................................................................................................... 2. - E. dodonaei Vill. 3    The style is deep 4-part. Stem cylindrical, without edges ...................................................................................... 4 3* The style is bat-shaped or spherical, undivided or weakly divided. Stem (excluding E. palustris) with longitudinal edges .................................................................................................................................................................. 8 4    Stem with spreading, dense, long simple and short glandular and simple hairs. Leaves sessile or nearly sessile .... 5 4* Stem close-fitting, short curly fluffy or almost naked. Leaves usually with petioles, sometimes too short ................ 6 5   Leaves oblong-lanceolate, wedge-shaped at the base, semi-covering the stem and slightly descending. Flowers usually 1 - 2 cm, rarely 0.6 - 0.9 cm long, usually over 1 cm in diameter. Stem usually 50 - 150 cm, rarely 14 - 30 cm high ... 3. - E. hirsutum L. 5* Leaves elongated to ovate-lance, rounded at the base, not stem-covering. Flowers smaller than 1 cm, 6 - 10 mm in diameter. Stem up to 85 cm high ............................................................................................................................... 4. - E. parviflorum Schreb. 6   Leaves at the base narrowly wedge-shaped narrowed into a stalk, 3 - 10 mm long, elliptically lanceolate. Petals white, then pink .............................. ..................................................................................................... 7. - E. lanceotatum Sebast. and Mauri 6* Leaves basically rounded, with petioles, usually shorter than 3 mm, ovate. Petals pink to bright red ........................... 7 7    Herbaceous to dark green plant. Stem simple or slightly branched. The leaves are usually 2 - 8 (10) cm long, 1 - 3 (-4) cm wide. Flower buds on top shortly pointed. Petals 5 - 10 (12) mm long. The box is 3 - 9 cm long, the is not ripe  abundantly glandular ….......................................................................................................................................................... 5. - E. montanum L. 7* Gray-green plant. The stem is often branched from the base. The leaves are 1 - 3 (4) cm long and 5 - 13 mm wide. Flower buds on top dull. Petals 3 - 6 mm long. The box (2) is 3 - 6 cm long, almost without glandular hairs .... 6. - E. collinum S.S. Gmel. 8 (3) The leaves of 3 (4) in vertebrae, rarely opposite or consecutive ……………..…….. 8. - E. alpestre (Jacq .) Crock. 8* Lower leaves opposite, upper consecutive ........................................................................................………………… 9 9  Stem cylindrical, without edges, at the base with above-ground fibrous shoots …......……...………. 9. - E. palustre L. 9* Stem with 2 - 4 clear, embossed and longitudinal edges .............................................................................…………. 10 10 Stem usually 20 - 40 (100) cm high, with numerous blossoms. Seeds back ovate, without transparent appendage on top ...……………….......................................................................................................................................… 11 10* Stem 5 - 20 (-30) cm high, with 1 - 4 blossoms. Seeds spindle-shaped, with spindle-shaped appendage on top ....... 13 11   Leaves on stalks 1 - 3 (-4) mm, rarely 4 - 15 mm long, narrowed at both ends. Inflorescence glandular fluffy .......................................................................................................................................................... 11. - E. roseum Schreb. 11* Leaves sat down or with too short petioles. Inflorescence without or only on the calyx tube with several glandular hairs ...................................................................................................................................................................................……. 12 12   Rhizome in autumn with long, widely leafy shoots. Leaves dark green, elongated lance, rounded at the base, shortly descending. Flower buds bent . ........................................................................................................................ 10. - E. obscurum Schreb. 12* Rhizome in autumn with sessile or short-stemmed rosettes. Leaves light or gray-green, linear-lanceolate with a wedge-shaped base. Flower buds erect or bent .................................................................................................................... 12. - E. tetragonum L. 13 (10 *) Rhizome with underground shoots, equipped with yellowish, fleshy, scaly leaves. Leaves ovate-lance, suddenly pointed, spaced shallowly serrated, Petals 6 - 12 (-16) mm long .................................................................... 13. - E. alsinifolium Vill. 13* Rhizome with aboveground, long shoots. Leaves ovate or elliptic, entire or almost entire. Petals 3 - 6 mm long .......... 14 14   The middle leaves are sessile, the shoots are thin, the rhizome with 1 or less stems, the inflorescence and the fruit are gray and fluffy. The style is bat-shaped. The seeds are gently warty .............................................................. 15. - E. nutans F. Schmidt 14* Middle leaves narrowed into short petioles; shoots almost as thick as the stem, the rhizome often with many stems, the inflorescence bare. The style is spherical. The seeds are smooth ........................................................................ 14. - E. anagalidifoliutn Lam. ¹ Developed by Yv. Ganchev. 29 Флора на Народна република България, т. VII From:    „Флора на Н. Р. България”, том VII, БАН, София, (1079)

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Epilobium is a genus of flowering plants in the family Onagraceae, containing about 197 species.[1] The genus has a worldwide distribution. It is most prevalent in the subarctic, temperate and subantarctic regions, whereas in the subtropics and tropics Epilobium species are restricted to the cool montane biomes, such as the New Guinea Highlands.
The taxonomy of the genus has varied between different botanists, but the modern trend is to include the previously recognised genera Boisduvalia, Pyrogennema and Zauschneria within Epilobium. Chamaenerion, previously (Chamerion), is considered distinct, however,[2] according to Peter H. Raven, who has extensively studied the willowherbs and merges the other segregate genera into Epilobium. Fringed willowherb (E. ciliatum) is likely a cryptic species complex; apparently these plants also commonly hybridize with their congeners.[3]
Most species are known by the common name willowherbs for their willow-like leaves.[4] Those that were once separated in Boisduvalia are called spike-primroses or boisduvalias. Those Epilobium species previously placed in the Chamaenerion group and known as fireweeds are now segregated into the genus Chamaenerion.

Description

Epilobiums are mostly herbaceous plants, either annual or perennial; a few are subshrubs. The leaves are opposite or rarely whorled,[5]:354 simple and ovate to lanceolate in shape. The flowers are actinomorphic (radially symmetrical) with four petals that may be notched.[5][6] These are usually smallish and pink in most species, but red, orange or yellow in a few. The fruit is a slender cylindrical capsule containing numerous seeds embedded in fine, soft silky fluff which disperses the seeds very effectively in the wind.
A number of Epilobium species with slightly asymmetrical (zygomorphic) magenta flowers and alternate leaves were placed in a Chamaenerion group, and have been separated by some authorities into the genus Chamerion. However, Chamerion has not been universally accepted[7] and there is now emerging consensus that this group of species should be segregated into the genus Chamaenerion.[8][9]

Habitat and ecology

Willowherbs sensu lato are typically very quick to carpet large swathes of ground and may become key or dominant species of local ecosystems. In the United Kingdom, for example, rosebay willowherb (Chamaenerion angustifolium) is widely found on mesotrophic soils dominated by false oat-grass (Arrhenatherum elatius), cock's-foot grass (Dactylis glomerata), and red fescue (Festuca rubra), while great willowherb (Epilobium hirsutum) is found in mesotrophic grassland with stinging nettle (Urtica dioica). These two willowherb species also dominate open habitat early in ecological succession, to the virtual exclusion of other plant life. Broad-leaved willowherb (Epilobium montanum) is found characteristically, though not abundantly, in the mesotrophic grasslands with meadowsweet (Filipendula ulmaria) and sometimes the uncommon Greek valerian (Polemonium caeruleum). Most willowherbs will not tolerate shade trees and thus are limited to more recently disturbed patches, yielding to other plants over time. Consequently, though the genus contains many pioneer plants, rather few of them are invasive weeds of major importance.
Epilobium species are used as food plants by the caterpillars of certain Lepidoptera species, including:
Geometridae

Use by humans

The main use of Epilobium by humans is as a herbal supplement in the treatment of prostate, bladder (incontinence) and hormone disorders. Many of the small willowherb species are nuisance weeds in gardens. Though few are regularly used as ornamental plants, the larger willowherbs may be attractive in ruderal locales. One of the most frequently recognized members of the genus is the circumboreal fireweed (E. angustifolium), known as rosebay willowherb in the United Kingdom. It rapidly colonizes burnt ground; during the bombing of London in World War II many of the derelict bomb sites were soon covered with these plants, bringing a splash of colour to what was otherwise a very grim scene. It is the floral emblem of Yukon in Canada, Hedmark in Norway (where it is called geitrams) and Southern Ostrobothnia in Finland.
Fireweed is used as a sweetener in northwestern North America. It is put in candy, jellies, ice cream, syrup, and sxusem ("Indian ice cream"). In the late summer its flowers yield pollen and copious nectar which give a rich spicy honey. Its young leaves, roots, and shoots are edible (if somewhat bitter), and rich in provitamin A and vitamin C. The Dena’ina found them also useful as food supplement for dogs and applied sap from the stem to wounds, believing it to have antiinflammatory properties.
Several researchers have studied this taxon. Heinrich Carl Haussknecht in the late 19th century and Peter H. Raven about a century later researched the phylogeny, systematics, and taxonomy of willowherbs. Peter Michaelis' studies of this genus paved the way for understanding of extranuclear inheritance in plants.

From Wikipedia, the free encyclopedia

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Epilobium

The genus Epilobium is in the family Onagraceae in the major group Angiosperms (Flowering plants).
Statistics are at the end of the page.

• The Plant List
• Angiosperms
• Onagraceae
• Epilobium

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Distribution in Bulgaria: (Conspectus of the Bulgarian Vascular Flora) = conspectus&gs_l= Zlc.
Distribution:

References: „Флора на Н. Р. България”, том VII, БАН, София, (1079), Wikipedia, the free encyclopedia, The Plant List

SPECIES:

Epilobium hirsutum L. - Great willowherb, Great hairy willowherb or Hairy willowherb

Epilobium montanum L. - Broad-leaved willowherb

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