A Monogr.ipli of the Geiins Alnrla. 77 



where the midrib continues to the stipe below. Sporophylls liolo- 

 soric, numerous, compactly disposed on both sides of the stipe, 

 adding new ones successively above, oblong-obovate, or elliptical, 

 12-20 cm. in length, 2-4 cm. in breadth, cartilaginous, with well- 

 defined cylindrical petioles ; base of sporophyll obtuse or round, 

 generally asymmetrical, tip round. Sorus on botli surfaces of each 

 sporophyll, in a continuous patch, occupying the whole surface 

 leaving but a narrow border along the margin sterile. 



Remarks on the species. This is a very distinct and well 

 marked species. The much interwoven, tall conical or mitriform 

 holdfast and the hollow but septated midrib are unrivalled charac- 

 ters among the allies. The sporophylls are ovate- spatulate, con- 

 siderable in number, and densely beset in a limited portion of 

 the stipe. At the beginning of appearance, they are membrana- 

 ceous and obovate, very densely disposed on the margins of the 

 stipe, /. c, in a manner quite different from other species. The 

 blade may often attain moi'o than 50 feet in length, 3 feet in 

 breadth, decussately cleft like a Musa leaf. It is the largest form 

 of Alaria. 



The plant grows gregariously at a depth of 5-10 fathoms 

 below the low water mark. The upper parts of the blades, when 

 the tide is low, float on the surface of the water and afford a 

 resting buoy for sea-otters and other marine fur-animals. 



Setchell and Gardner distinguished two forma\ f. platyphyUa 

 and f. stcnophjlla, from the Unalaskan forms. But judging from 

 the descriptions and considering the Kurile specimens, the forma? 

 proposed seem merely due to tlie state of growth, as has been 

 already observed by Kibbe.^) 



The specimen kept in the herbarium of the Botanical Museum 



1) KiBBE : Puget Sound Mar. Station Publ., "\'oI. I, i?. 43. 



