This rust fungus has infected the stinging nettle Urtica incisa forming galls on stems and leaves. Puccinia urticata is a macrocyclic-heteroecious rust that forms the pycnial (spermogonial) and aecial stages on one host and the uredinial and telial stages on another host. The other host in this case is likely to be a species of Carex. Aecia and aeciospores are shown in images 4 & 5. See Kern F.D. (1917) North American Species of Puccinia on Carex. Mycologia 9 (4) pp 205-238.