Oct. IMS.] #: OKAMVBA.— UNDARIA AND ITS SPECIES. 275 



This species in many respects very closety resembles Undaria 

 pinnatiGda, only differing in the form of broadly ovate, less 

 pinnate and often deeply undulated frond. When matured it 

 differs' from that species in always having sori over the costal 

 area and the wings are in many cases transformed into more 

 or less well denned sporophylls. It is also so closely resembl- 

 ing with Undaria Peterseniana that when the midrib is weakly 

 prominent it is not often eas}- to distinguish one from the other. 



3). Undaria Peterseniana (Kjellm.) 



=Larninaria Peterseniana Kjellm. in Kjellm. och 

 Petersen Om Japans Laminar, p. 267, Taf. 10, f. 

 2-3 ; Okam. Om Laminaria of Japan (Bot. Mag. 

 Tokyo Vol. X, 1896) p. 97, PI. VII, f. 13-11. 

 = Undariopsis Peterseniana (Kjellm.) Miyabe et Oka- 

 mura mscr. in Okam. Nippon Sorui Meii p. 128, 

 1902 (without diagnosis). 



Root fibrous, distichously arising at the beginning ; stipe 

 long (3— 50cm.), ancipito-compressed, winged; lamina broadly 

 linear-lanceolate, oblong, ovate or roundish, with cuneate, ovate 

 or deeply cordate or auriculate base, 100 cm.— 3.5 m. long, 

 25-30 cm. broad, subpapyraceous, more or less thickened into 

 median fascia, deeply and closely undulato-plicated. Sori broadly 

 linear formed on both surfaces of fascia. 



hoc. Prov. Iki, Prov. Tsushima and Goto Islands, Prov. 

 Tajima (De Toni), Prov. Yechizen (Prof. Yendo), Prov. Kii, Shi- 

 moda and Kozushima (Prov. Idzu), Uraga (Prov. Sagami) ; 

 Sunosaki and Nemoto (Prov. Boshyu). 



Undaria Peterseniana may easily be distinguished from the 

 other two related species by its usually linear-lanceolate, entire- 

 margined frond having more or less broad fascia and by broad- 

 ly linear sorus (5-7 cm. broad in the specimens from Prov. 

 Boshyu). The surface of frond is usually smooth, but in some 

 specimens rugoso-bullated and cryptostomata are' mostly less 

 significant and fewer than the other two. The colour of frond 

 is olive-brown which turns to greenish when dried as in the 

 other two species, but often a little more brownish than those 

 plants. 



