46 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM, 



A few other species exhibit a marked predikn-tion for proximity to 

 the sea witliout being apparently either sand-loving or salt-loving 

 j)lants. Such are : 



Ariciiii-sid siij.sdorpi. Poa jxiclnjpliiilis. 



CaluiiKii/roxtis (ilcutica. I'oliiixxUu)!! xcoiiJcri. 



IlilihixtiiJiis borcdlis. ,S(ili,c liookcridint. 



Il!/ihiKti/lii>t hrac]t!/p}is. Scldt/incJhi stnitli ioloidcs. 



In addition to these the marine aquatic genera Zostera and Phyl- 

 lospadix deserve mention as our only genera of flowering plants 

 found in the ocean. The related Iixppki maritlma occurs in brackish 

 waters. 



SPHAGNUM BOGS. 



Sphagnum bogs are quite connnon throughout western AVashington. 

 The usual shrubs are Labrador tea {Ledum laflfoliii///), laurel {Kal- 

 mid (flauca), and cranberry {OxycoccKS oxycoccvs intermedins). 

 Usually a willow {Salix inyrtilloideH) ^ sweet gale {Myriea gcde)^ and 

 a dwarf birch (Hetida ghindtdosa) arc present also. On the drier 

 hummocks small hendocks {TsiK/a lieteropliyUa) often occur, and in 

 similar situations one is often sur})rised to find the black.pine {Pinus 

 eonto/'ta), typically a i)lant of barren, graA'clly or sandy soil. 



The more interesting and characteristic herbs are sundew {Droscru 

 rotund if olia)^ cotton-grass {Efiophorum russeolum)^ Scheuchzeria 

 p<dustris, and Juncus oregana. 



In the bogs near the ocean coast Ledum eolunihianum and Myr'tca 

 ealif arnica replace their two close relatives. 



THE COASTAB STRIP 



One other important forest association of Washington, namely, the 

 tideland or Sitka spruce forests, in innnediate proximity to the Pacific 

 Ocean, is jierhaps best classed as Humid Transition zone rather than 

 otherwise. The facts in the distribution of this species are peculiar. 

 It is the dominant tree, forming over 50 per cent of the forest strip, 

 along the coast from middle Oregon noi'thward to Kadiak Island, 

 beyond which all timber ceases, and the flora becomes almost that of 

 the Artie Zone. Therefore we have this one species of tree dominat- 

 ing a continuous stretch of sea level, from the Arctic Zone to the 

 Humid Transition, through both the Hudsonian and the Canadian 

 /ones. In the north the Sitka spruce forests end sharply with the 

 arctic meadows. In the south they merge imperceptibly wnth the 

 red-fir forests. This enormous stretch of a single species at sea level 

 is probably due to the remarkal)ly equable temperature and great 

 humidity of th(i immediate seacoast. 



