Equisetum arvense f. arvense (field horsetail, "Sugina")

Japanese name: スギナ （杉菜）
Scientific name: Equisetum arvense f. arvense

[Overview]
A summer-green terrestrial fern found on sunny roadsides, vacant lots, paddy ridges and in fields.
The underground stem extends far and sends up aerial stems from its nodes, so it spreads vigorously and becomes a weed that is hard to control.
There are two types of aerial stems: vegetative stems and spore-bearing stems.
The leaves are reduced, brownish, and whorled at the nodes of the stem.
This is the part called the "hakama" (skirt).
The vegetative stem is 20–40 cm tall, hollow and green, with several vertical grooves.
Many branches are whorled at the nodes of the stem.
The spore-bearing stems are called tsukushi.
The spore-bearing stem is unbranched, hollow, and pale brown to pale pink, with a sporangial spike 2–4 cm long at the tip.
The spores are green.
The spore-bearing stem withers soon after releasing its spores.

[Uses]
The spore-bearing stems (tsukushi) are eaten.
The vegetative stems are called monkei and are used as a folk medicine, for example as a diuretic and to stop bleeding.

[Notes]
The name compares the form of the vegetative stem to the shape of a sugi tree.

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