174 University of California Puhlications i)i Botany [Vol.8 



5. Codium tomentosum (IIiuls.) Stat-kh. 



Tliallus ratlier slender, much branched, 22-37 cm. hi<>h when grow- 

 ing in pools, 48-60 cm. high when growing in deep water, 3-4 mm. 

 thick, cylindrical, often slightly flattened at the axis, dichotomous, 

 surface often very tomentose, becoming smooth with age, color dark 

 green; utricles cylindrical, small, 500-650/x long, 120-170/x, (rarely to 

 220/i) wide, apex usually distinctly thickened, blunt; smaller utricles 

 sometimes pointed, but never mucronate; gametangia (5) small, 200- 

 250/i long, 40-70/x wide; gametes 20-22;u long, 10-12^ wide. 



La Paz, Lower California. 



Stackhouse, Ner. Brit. (fasc. 3), 1801, p. xxiv; pi. 7; Howe, 

 Phyc. Studies V, 1911, p. 493; Collins, Green Alg. N. A., 1909, p. 388; 

 Harvey, Phyc. Brit., 1846, pi. 93 ; Vickers, Phyc. Barb., 1908, p. 22, 

 pi. 26. Fucus tomentosus Hudson, Flora Anglica, 1778, p. 584. 



In attempting to arrange the erect branched species of our coast 

 with non-mucronate utricles, we are confronted with a problem of 

 which the solution seems impossible at present. In the first place, 

 the material available to us is slight ; in the second place, the reference 

 of the similar species of Europe and other parts of the world is not 

 at all satisfactory; and in the third place it is impossible at present 

 to examine the types of the hitherto described species of this group. 

 AVhen we add to this a lack of knowledge as to the possible variation 

 in habit and size of utricle of the species of Codium, it seems sufficient 

 to prevent us from presenting any but a tentative, and by no means 

 satisfactory, arrangement. We have decided to refer our plants of 

 this group under two species, viz., C. tomentosum (Huds.) Stackh. 

 and C. decorticatum (Woodw.) Howe. 



Codium tomentosum was originall}^ described from Exmouth in 

 Devon, on the south coast of England. The type specimen will pre- 

 sumably be found in the Buddie Herbarium in the British Museum, 

 but no account has been published as to its exact nature. Cotton 

 (1912, p. 114) has published an exact description of the Clare Island 

 plant which, presumably, is true C. tomentosum, and we have adopted 

 this in our diagnosis. We may assume that the typical form is a 

 slender, much branched plant, of varying length, cylindrical, or often 

 slightly flattened just below the axils and with slender utricles, "120- 

 170/A (rarely to 220/a) wide," with apex distinctly thickened and blunt 

 or at times pointed, but never mucronate. We have never seen a 

 plant from our coast answering to this description. Howe {loc. cit.) 

 has referred here a plant from La Paz, Lower California. He also 



