Equisetum arvense (Horsetail)
Latin equisetum, horsetail ; arvense, of fields
Equisetum produces terminal strobili, each of which consists of numerous stalked pads. Sporangia on the inner surface of the pads produce many spores. E. arvense ( the tallest shoot in the photo ) produces branchless, fertile shoots which develop before the vegetative shoots. E. sylvaticum ( leaning against E. arvense, far right in photo) produces strobili first, but then develops branches on the same shoots.