Translations:Manfred Klett: Von der Agrartechnologie zur Landbaukunst/1331/en

Strikingly absent from the stinging nettle is that sharp accentuation of the polarity between root and blossom which is so characteristic of the composite plants yarrow and chamomile; it belongs to the order of Urticales. With its inconspicuous inflorescences it submerges into the foliage of the upper third of the stem. The flowers grow from the leaf axils of the strictly decussate, storey-upon-storey arranged leaves (Figure 28, p. 383). The pollen-bearing plants show a more elongated leaf blade and a rounded serration of the leaf margin; those bearing fruit, by contrast, have a more compact, heart-shaped leaf blade and a sharply pointed serration. The leaf metamorphosis reveals itself only weakly: already in the lowest leaf the type of the plant discloses itself, with a pronounced though still somewhat rounded serration and a covering of stinging hairs; even the cotyledons already bear them. Moving upward toward the middle of the shoot, the leaf blade broadens into an emphatic heart-shape, and toward the tip of the stem it narrows again into finely and sharply serrated, lanceolate forms.