Field Horsetail (Equisetum arvense) with buttercups; photo ref.: buttercups+horsetails_ANP_©DaveSpier_D006695t+DS
Observation by me, Anna Ivaschenko & Vladimir Kolbintsev
A large patch, all double branched. Not one anomalous plant.
Common horsetail. Green stem and branches, 70 cm tall, ridges where branches grow. Branches are long and skinny, needle-like.
Equisetum arvense, the field horsetail or common horsetail, is a herbaceous perennial plant, native throughout the arctic and temperate regions of the northern hemisphere. It has separate sterile non-reproductive and fertile spore-bearing stems, growing from a perennial underground rhizomatous stem system. The fertile stems are produced in early spring and are non-photosynthetic, while the green sterile stems start to grow after the fertile stems have wilted, and persist through the summer until the first autumn frosts.