208 Vniversity of California Puhlic-ations in Botany [Vol.8 



The determination of species of Cl-adophora presents unusual 

 difficulties. The synonymy, especially' of older specific names, is very 

 much unsettled and iutertangled. The identity between species of 

 different coasts and oceans is verj- uncertain, and the recognition of 

 species in their various ages and under varying conditions seemingly 

 most difficult. We have adapted our account very largelj' from Col- 

 lins (1909) and have accepted his determinations and limitations of 

 species, since we ourselves have very little opportunity for the study 

 of this genus and possess few facilities for the proper comparison of 

 our ■^vest coast plants with authentically determined specimens from 

 other coa.sts. It is desirable that collectors pay careful attention to 

 these plants, to their seasonal conditions, their fertile states, their 

 earlier stages of growth as well as adult, and attempt to make better 

 known the entire life-history of our various species and forms. 



Key to the Species 



1. Low, pulvinate or matted, creeping at the base 2 



I. Erect, tufted or loosely spreading 4 



2. Branching irregular, not at all dichotomous 1. C. amphibia (p. 209) 



2. Branching dichotomous or trichotomous, except above 3 



3. Main filaments 60-150m in diameter 2. C. hemisphaerica (p. 209) 



3. Main filaments 120-250/u in diameter 3. C. trichotoma (p. 210) 



4. Main filaments usually over 150ai in diameter 5 



4. Main filaments usually under 150ju in diameter 9 



5. Lower segments 10 or more diameters long 4. C. graminea (p. 211) 



5. Lower segments less than 10 diameters long 6 



6. Hamuli curved 5. C. microcladioides (p. 212) 



6. Hamuli straight 7 



7. Hamuli only slightly less stout than branches 6. C. Hutchinsiae (p. 213) 



7. Hamuli very much less stout than branches 8 



8. Main filaments 112-200/x in diameter 7. C. ovoidea (p. 214) 



8. Main filaments 135-300ai in diameter 8. C. MacDougalii (p. 214) 



9. Main filaments distinctly zig-zag or flexuous 10 



9. Main filaments straight or nearly so 13 



10. Hamuli clustered at the tips 9. C. laetevirens (p. 216) 



10. Hamuli not clustered at the tips 11 



II. Main filaments coarse, up to 150 (or 160) /j. 10. C. gracilis (p. 216) 



11. Main filaments slender, not over 80^ 12 



12. Segments long below (up to 6 diam.), shorter (as low as 2 diam.) above 



11. C. flexuosa (p. 217) 



12. Segments long throughout 12. C. Rudolphiana (p. 217) 



13. Hamuli curved 13. C. Bertolonii var. hamosa (p. 218) 



13. Hamuli straight 14 



14. Main filaments not over 30^ in diameter 14. C. albida (p. 218) 



14. Main filaments considerably over 30^ in diameter 15 



15. Hamuli acute 15. C. glaucescens (p. 219) 



15. Hamuli blunt 16 



16. Branching dichotomous below the tips 16. C. Stimpsonii (p. 219) 



16. Branching nowhere dichotomous 17. C. delicatula (p. 220) 



