N0.1226. NORTH AMERICAN FERNS— MAXON. (U5 



AZOLLA Lam. Encyc. 1: 3i3. 1T83. 



Azolla caroliniana Willd. Sp. PI. 5; 541. 181(>. 



Xew Yi)i-k to Florida, Arizona, California, and C)ret;on. 



Azolla filiculoides Lam. Encve. 1 : 343. 1783. 



California. Probal)ly of wider range. Introdnced at Sprintrfield, Massachusetts 



{A.A.Eaton). 



Family IX. EQUISETACEAE Miehx. Fl. Bor. Am. 2 : 281. 1803. 

 EauISETUM L. Sp. PI. KiOl. 1753. 



Equisetum arvense L. Sp. PL 1061. 1753. Com3IOX horse-tail. 



Virginia to California, north to Newfoundland and Alaska. Also in Greenland. 

 Very variable, apparently presenting no stable subspecies. 



Equisetum pratense Ehrli. Hannov. Mag. 1784; 138. 1784. 



Xova Scotia t(> Alaska, south to New Jersey, ^Minnesota, Nebraska, and Colorado. 



Equisetum telmateia Ehrli. Hamiciv. Mag. 1783: 287. 1783. 



California to ]>ritish Columbia. 

 Equisetum sylvaticum L. Sp. PI. loOl. 1753. "Wood horse-tail. 



Newfoundland and Labrador to Alaska, south to Virginia and Nebraska. Also 

 in Greenland. 



Equisetum palustre L. Sp. PI. 1061. 1753. Marsh horse-tail. 



Nova Scotia to Saskatchewan and Alaska, south to Maine, Connecticut, western 

 New York, Illinois, ^Minnesota (?), and Washington. 



Equisetum littorale Kiihl. : Eupr. Beitr. Pilanzenk. Russ. Reich. 4: 1»1. 

 1845. Joint-grass. 



]Maine and Ontario to New Jersey an<l Pennsylvania, west to Minnesota {HoJzbiger) . 

 Equisetum fluviatile L. Sp. PI. In62. 1753. Swamp horse-tail. Toad- 

 pipes. Joint-grass. 



Equisetum limosum L. Sp. PI. 1062. 1753. 

 Nova Scotia to Alaska, south to Virginia, Kansas, and "Washington. 



Equisetum ramosissimum Desf. FI. Atl, 2 : 398. 1800. 



Vancouver Island, British Columbia {Lyell). Also in southern California 



{Ihirhhn,,). 



Equisetum mexicanum Milde, Yerhaudl. k.-k. zoolog.-bot. Cxesell. 12": 

 1256. 1862. 

 San Bernardino and Los Angeles counties, California. 



Equisetum robustum A. Br. Am. Journ. Sci. 46: 88. 1844. 



New Jersey to Georgia and Louisiana, west to British Columbia and California. 



Equisetum hyemale L. Sp. PI. 1(»62. 1753. Scouring-rush. Pipes. 

 Shave-grass. 



Quebec and New England to \'irginia, Texas, California, Washington, and Brit- 

 ish Columbia. 



Equisetum laevigatum A. Br. Am. Journ. Sri. 46: s7. 1844. Smooth 

 scouring-rush. 



New Jersey to North Carolina and Louisiana, west to British Columbia, Oregon, 

 California, and Texas. 



