【Municipal Designation：Natural Monument (Flora)】Miyako-Hanawarabi (Helminthostachys zeylanica)

The Miyakojima-Hanawarabi is a perennial plant of the genus Helminthostachys of the Ophioglossaceae family, and the Miyakojima-Hanawarabi is the only species that make up this genus. Its thick rhizome cross-feeds into the earth. The soft, dark-green stalk grows straight aboveground to 20 to 40cm high. The sterile leaves separate in threes, and each splits further into three or four parts. The leaf lobes are oblong, measuring 6-18cm in length and have a thin, paper-like texture with a glossy frontal side. The edges of the leaves have irregular, fine serrations. The fertile fronds grow at the clefts of the sterile leaves, and they are column-shaped, and measure 4-20cm. The species are found in slightly marshy areas of open forests.
Within Japan, this species is found on Okierabu, Okinawa, Kume, Miyako, Ishigaki, Kohama, and Iriomote Islands, and overseas, the species grows in Taiwan, southern China, Southeast Asia, New Guinea, Polynesia, New Caledonia, and other locations.
The Ryukyu Archipelago is almost the northernmost point where this plant grows, and it is an important sample in phytogeographic studies in the research of plants growing in the northern limits.