A large number of benimansaku, which grow wild, can be found from the
vicinity of the Watanose Reservoir in former Ono-cho to Tomota, former
Saiki-cho(present Hatsukaichi City). They have been designated as a natural
monument of the prefecture. Around Benimansaku Lake in Ikoi no Mori, located
on the eastern side of the reservoir, is the easiest spot to observe them.
 This species is a deciduous shrub belonging to the hamamelidaceae, also called
marubanoki. It is an interesting plant which is distributed at intervals in the
Chubu district and part of Shiga, Kochi, and Hiroshima Prefectures. It is
commonly called marubasha or nihegi or lately bannoki (a word shortened
from marubanoki) by the local people. The plants grow in abundance in Bannoki
Ravine in the vicinity of Karasugaoka.
 The height of the tree is one to three meters, and its leaf has the shape of a round
heart with no fimbriation. It is beautiful when it turns crimson in late autumn. At
the same time, dark red flowers in the shape of stars bloom by twos, back to
back, on the short branches. A species that is very similar is distributed
throughout China. It is called sokaboku (two-flower tree) there because of the
pairs of flowers. The flower has a fragrance which is similar to that of Houttuynia
chordate, and its shape and color of autumnal tints have a bewitching impression.