S86 Puget Sound Marine Sta. Pub. Vol. 1, No. 31 



the active growing period of early spring, when elongation of the thallus 

 takes place, and the period of differentiation of tissues which imjnediately 

 follows and continues throughout the summer. 



During the dormant period the plant has a stiff, ragged appearance, 

 due to the shedding of much of the previous season's growth. At the be- 

 ginning of the growing season, which varies with the latitude, new shoots 

 appear, many of them arising adventitiously in the axils of old branches, 

 or of the stubs which remain when the old branches are shed. The older 

 parts of the plant are hard and leathery, and dark brown in color, but 

 the new growth is soft and flaccid and a yellowish brown, becoming harder 

 and darker as the growing season advances. Plants in the winter condition, 

 or the older parts of plants that have grown for several seasons, are 

 quite hard and rigid, and do not show the characteristic softening and 

 change of color; but the young branches of plants collected during the 

 summer change color and decompose quite rapidly. 



DESMARESTiA MEDIA (Ag.) Grcv. was first published by C. A. Agardh 

 (1) under the name of Sporochnus medius, habitat Unalaschka. It is the 

 D. intermedia of Postels and Ruprecht (21), and held specific rank under 

 various names until reduced to a variety of T>. aculeata by J. G. Agardh 

 (2). Since that time some writers have followed Greville, others Agardh, 

 until about 1895, possibly thru De Toni's "Sylloge Algarum" (4), 

 Agardh's classification seems to have become fixed in the literature. 



Borgeson (3) says of Faeroese specimens that "the typical var. media 

 differs rather widely from typical D. aculeata, and consequently it might 

 ])erhaps more properly be regarded as a distinct species." Setchell and 

 Gardner (26) consider their Pacific coast specimens to be so distinct from 

 the ordinar}^ typical D. aculeata that they "are sorely tempted to restore 

 them to specific rank." 



According to the writer's observations, the plants have not the adven- 

 titious branching so characteristic of D. aculeata; neither main axis nor 

 branches are flattened, as is the case in the type species ; according ta 

 practically every description by various authors, the branches are almost 

 all opposite, while in the type species the branches are all alternate. More- 

 over, the plant body is lighter in color-and softer in texture; and not mere- 

 ly the young and tender branches but the whole plant body shows the 

 characteristic softening and change of color on exposure to the air or when 

 allowed to stand for a short time in a vessel of water, either salt or fresh. 



With so many differences in appearance and habit, the writer feels 

 that there is no justification for subordinating D. media to D. aculeata. 

 She therefore proposes that this plant be restored to specific rank, under 

 the name Desmarestia media, first published by Greville. 



