Epilobium willisii

Description

The biological form of Epilobium parviflorum is hemicryptophyte scapose, as its overwintering buds are situated just below the soil surface and the floral axis is more or less erect with a few leaves. Epilobium parviflorum reaches on average 30–80 centimetres (12–31 in) in height. The stem is erect and densely covered with hairs, especially in the lower part. The leaves are opposite, unstalked but not amplexicaul, lanceolate and toothed, rounded at the base, 4–10 centimetres (1.6–3.9 in) long. The tiny flowers are pale pink or pale purple, 6–7 millimetres (0.24–0.28 in) in diameter, with four petals, eight stamens and a 4-lobed stigma. Flowering occurs from June to August. The hermaphroditic flowers are either self-fertilized (autogamy) or pollinated by insects (entomogamy). Fruit is a three-to seven-centimeter long capsule containing very small black seeds (about 1 mm long), with white fibres that allow the dispersal by wind. This species is quite similar to Epilobium hirsutum, but the flowers are much smaller.