24 
K. MIYABE 
are all provided with a filamentous holdfast; a species provided 
with a discoid holdfast like the present has not been known to 
science. So the author proposes here to name it Laminaria yezoensis 
as a new species. 
12. Laminaria Ruprechtii (Arescu.) De Toni 
(Plate 14) 
De Toni, Syll. Alg., Ill, p. 339, 1895. 
Syn. Hafgygia Ruprechtii Areschoug, Observ. Phyc., IV, p. 4, 1883. 
Japanese name. Chishima-gohei-kombu. 
Chishima-heisoku-kombu. 
Holdfst composed of filamentous hapteres branching 5-6 times, 
arising in whorls, the uppermost one of which is composed of ca. 
14 hapteres. Stipe very long, solid, smooth on surface, rigid, 
cylindrical for a short distance at the basal portion but more or 
less complanated in the remaining portion which expands at its 
top into the blade, perennial and provided with annual rings, up 
to 0.7-1. 5 m in length, 2.5-2.8cm in diameter below, 3.0 x0.6 cm in 
the middle portion. Blade broad-elliptical as a whole, split palmate- 
ly into segments, round and thick at the base ; segments thin and 
sword-shaped ; ca. 80 cm in length, 40 cm in total breadth; segments 
2-3 cm in breadth; light brown in color; sporangial sori unknown. 
Stipe has a row of large mucilage ducts closely set. Blade 
also has a row of the ducts. 
Habitat and distribution. The specimens collected by Yanagawa, 
technician of the Hokkaido Prefectural Government, at Iriribushi, 
Naiho Village, on the eastern coast of Etorofu Island, Kuriles, in 
September 1893, are the only material now at hand. So the range 
of distribution of this species in our region is not clear yet, though 
it probably is to be found throughout the Kurile Island. It is to 
be regretted that the matter could not be fully studied on account 
of the scantiness of the material. The present plant coincides 
most closely with Laminaria Ruprechtii that grows on the coasts of 
Sitka Island, Alaska. So it is referred to that species. 2 " 0 
23) MlYAEE (1928, pp. 955-956) states : “A digitate Laminaria, collected on the 
eastern coast of Etorofu, and erroneously identified by the author as Laminaria 
Ruprechtii is most likely a remarkably well developed form of the species under 
consideration ( Laminaria ; dentigera K.JELLM.).” However, MlYAEE and NAGAI (1932, p. 
201) identify MlYABE’s Laminaria Ruprechtii from Etorofu Island with Laminaria 
platymeris De la PYL. (Cf. also, MlYAEE, in OKAMURA, 1936, pp. 289-290). 
