Japanese name: イヌスギナ（犬杉菜） Scientific name:Equisetum palustre
[Overview]
A summer-green terrestrial fern found in sunny wetlands and along rivers.
The underground stem extends far and sends up aerial stems from its nodes, often forming colonies.
There are two types of aerial stems, vegetative stems and spore-bearing stems, but they have the same form.
The aerial stem is 20–60 cm tall, 0.2–0.4 cm in diameter at the base, with 5–10 somewhat conspicuous vertical grooves.
In the upper part of the stem, branches are whorled at regular intervals, and the tip of the main axis extends long without producing branches.
The leaves are reduced and whorled at the nodes of the stem, forming the so-called "hakama" (skirt).
The hakama on the main axis is longer than the lowest internode of the branches.
A sporangial spike 1–3.5 cm long is borne at the tip of the spore-bearing stem.
