Epilobium tetragonum L.

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

Foodplant / pathogen
aecium of Puccinia pulverulenta infects and damages live Epilobium tetragonum

Foodplant / spot causer
amphigenous, minute, brown pycnidium of Septoria coelomycetous anamorph of Septoria epilobii causes spots on live leaf of Epilobium tetragonum
Remarks: season: 7-8

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

Rank clumped erect perennial herb, producing leafy basal rosettes; stems 10-130 cm tall, well-branched, strigillose all around above or nearly glabrous, with strigillose raised lines decurrent from the margins of the petioles. Leaves narrowly lanceolate to lance-elliptic, 1.5-7.5 x 0.3-1.5 cm, glabrous except for sparse hairs on main veins, veins conspicuous, margins coarse serrate, apex acute or acuminate, base attenuate or truncate, sessile and decurrent. Inflorescence erect, strigillose and eglandular. Ovaries strigillose, 3-5 cm long, pedicels 1-2 cm long. Sepals strigillose, keeled, 2.8-4.2 x 0.8-1.8 mm. Petals 2.5-6 x 2-3.5 mm, notched, pink to purple. Style 1.5-3.2 mm long. Stigma clavate, 1.8-3 mm long, surrounded by anthers at anthesis. Capsules strigillose, 3.5-8 cm, on pedicels 1-3 cm. Seeds 1-1.3 x 0.4-0.5 mm, obovoid, coarsely papillose; coma 6-8 mm long, easily deciduous.

Distribution: Europe except extreme north, to Caucasus and Central Asia; North Africa, South Africa; adventive in Australasia and South America.

This collection is the only authentic material of this species from the flora region, and indeed from the entire Himalaya. The closest other collections of the species are from the Tien Shan region and western Iran, each nearly 1000 km distant. It is difficult to imagine, however, that it is introduced at this remote locality.

Epilobium adnatum Griseb., Bot. Zeitung 10: 854. 1852; Hausskn., Monogr. Epil. 97. 1884; Shteinb. in Schischkin & Bobrov, Fl. URSS 15: 586. 1949.

Epilobium tetragonum, commonly known as the square stalked willow herb, is a species of flowering plant in the willowherb family Onagraceae.

The erect perennial herb typically grows to a height of 0.1 to 1.3 metres (0.3 to 4.3 ft) and can have several stems. It blooms between January and November and produces pink-purple flowers.

The species has become naturalised in the Perth and Peel regions of Western Australia.