Favoritos de je9h

Photo key:

1. Whole monoecious plant
2. Wilted male inflorescence
3. Fruiting female inflorescence
4. Pistillate flowers at anthesis
5. Female flowers with fruits
6. Subcircular achene
7. Male flower remnants
8. Male stamen & tepal remnants

Link to the paper that revives the name U. gracilis for North American nettles:

https://www.researchgate.net/publication/260815095_Weeding_the_Nettles_II_A_delimitation_of_'Urtica_dioica_L'_Urticaceae_based_on_morphological_and_molecular_data_including_a_rehabilitation_of_Urtica_gracilis_Ait

And the revised Flora of the Pacific Northwest key:

https://www.pnwherbaria.org/florapnw/treatmentpdfs/Urtica_FloraPNW_Revised.pdf