Epilobium palustre L.

Foodplant / saprobe
apothecium of Hymenoscyphus repandus is saprobic on dead stem of Epilobium palustre
Remarks: season: 5-10

Foodplant / gall
larva of Mompha divisella causes gall of stem of Epilobium palustre

Foodplant / spot causer
hypophyllous pseudostroma of Ramularia anamorph of Phaeoramularia punctiformis causes spots on live leaf of Epilobium palustre
Remarks: season: 8-9

Foodplant / parasite
hypophyllous telium of Puccinia epilobii parasitises live leaf of Epilobium palustre

Foodplant / parasite
intercellular spores of telium of Pucciniastrum epilobii parasitises live Epilobium palustre
Remarks: season: 8-10

In Great Britain and/or Ireland:
Foodplant / parasite
cleistothecium of Sphaerotheca epilobii parasitises live Epilobium palustre
Remarks: season: 8-10

Foodplant / spot causer
epiphyllous, clustered pseudothecium of Venturia maculiformis causes spots on live leaf of Epilobium palustre
Remarks: season: 5-9

This extremely widespread circumboreal species occurs only sporadically in the Himalayan region; Raven's (1962) suggestion that it entered the region relatively recently from the west may account for this sparse distribution. Although specimens of E. palustre vary greatly in stature and in size of leaves, flowers, etc., this variation is highly reticulate and lacks any obvious geographical or ecological basis; we therefore treat the species without any infraspecific taxa. Fl. Per.: Jun-Aug. Fr. Per.: Jul-Sep.

Herbs perennial, erect, with filiform stolons terminating in small fleshy turions that leave brown basal scales. Stems (5-)15-70 cm tall, simple or well-branched, strigillose throughout or subglabrous on lower part, rarely with lines decurrent from margins of petioles. Leaves sessile or petioles to 3 mm; cauline blade sublinear to narrowly lanceolate or elliptic, 1.2-7 × 0.3-1.2(-1.9) cm, sparsely strigillose adaxially and on abaxial veins or rarely glabrescent, base rounded or cuneate, margin entire to obscurely denticulate with 5-9 teeth per side, occasionally revolute, apex acute or obtuse. Inflorescence erect or slightly nodding in bud, densely strigillose, sometimes with glandular hairs; flowers erect. Sepals 2.5-4.5 mm. Petals white to pink, 3-7(-9) mm. Stigma clavate to subcylindric, entire. Capsules 3-9 cm, strigillose; pedicels 1-5 cm. Seeds brown, (1.1-)1.3-2.2 mm, finely papillose, with prominent chalazal collar 0.08-0.3 mm; coma dull white or rarely tawny, not easily detaching. Fl. Jun-Aug, fr. Aug-Sep. 2n = 36.

Erect variable perennial herb, forming filiform epigaeous stolons with widely spaced small leaves, often terminating in condensed dark small turions; stems 5-70 cm tall, terete, simple or well-branched in larger plants, subglabrous below except for strigillose lines decurrent from the margins of the petioles, dense strigillose above. Leaves sublinear to narrow lanceolate, 1.5-7 x 0.2-1.9 cm, subglabrous except for strigillose margins and veins, entire to obscurely denticulate, apex acute or acuminate, base cuneate, sessile. Inflorescence nodding in bud, dense strigillose, usually eglandular. Ovaries 2.1-3 cm long, densely canescent. Sepals 2.5-4.5 mm long, strigillose. Petals 3-9 mm long, white or rarely pink. Style 2-3.8 mm long. Stigma clavate to cylindrical, surrounded by anthers at anthesis. Capsules 3-9 cm long, pubescent, on pedicels 1.5-3.5 cm long. Seeds 1.4-2.2 x 0.38-0.54 mm, elliptic-attenuate or fusiform, very finely papillose, the chalazal collar 0.08-0.24 mm long, very conspicuous; comas 5-7 mm long, white, quite persistent.

Temperate Eurasia, Himalaya, Tibet, east to Japan, N. America, Greenland.

Gansu, Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Qinghai, Shaanxi, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan [India, Japan, Kazakhstan, Korea, Mongolia, Nepal, Pakistan, Russia; widespread in C, N, and SW Asia, Europe, and North America (including Greenland)].

Distribution: Circumboreal, in the Himalaya from Kashmir to Nepal and Southern Tibet.

4400-4900 m

Wet places along streams, rivers, bogs, and marshes, often disturbed, and in subalpine meadows, widespread; 200-4500(-5000) m.

Epilobium fischerianum Pavlov; E. palustre var. lavandulifolium Lecoq & Lamotte ex Haussknecht; E. palustre var. majus C. B. Clarke; E. palustre var. minimum C. B. Clarke; E. rhynchocarpum Boissier.

Epilobium palustre L. var. typicum Clarke in Hook. f., Fl. Brit. Ind. 2: 585. 1879. Epilobium palustre L. var. majus Clarke in Hook. f., loc. cit. 2: 585. 1879. (No authentic material seen.) Epilobium palustre L. var. minimum Clarke in Hook. f., loc. cit. 2: 586. 1879. Lectotype: Kashmir: Deosai, 3950 m, 31.7.1876, Clarke 29816 (K).

Epilobium palustre is a species of willowherb known by the common name marsh willowherb. This plant has a circumboreal distribution, and can be found farther south in mountainous areas.