covery of the magnificent Aspidium which bears his name, but 

 the botany of flowering plants also is largely his debtor. His re- 

 searches brought to light many new plants and it is likely that 

 the list to his credit would have been much longer had his collec- 

 tions escaped destruction. During his residence in Canada he 

 kept up a correspondence with many prominent botanists and 

 published numerous articles in the Edinburgh Philosophical 

 Journal. I am indebted to James Goldie, Esq., the son of John 

 Goldie and himself a botanist and fern lover, for the material 

 from which this sketch was prepared. 



THE GENUS EQUISETUM WITH REFERENCE TO THE 

 NORTH AMERICAN SPECIES. 



By Alvah A. Eaton. 



FIFTH PAPER. 



E. Telmateia Ehrh. 



RHIZOME dark brown, tuberiferous. clothed with cinnamon- 

 colored felt, very slightly grooved, central cavity wanting, 

 but large vallecular and small carnial ones present. Stems 

 dimorphous ; fertile, often clustered, 1-2 ft. tall, y 2 -1 in diame- 

 ter, white, smooth, succulent, produced in early spring and soon 

 perishing; lower internodes shorter than sheaths, upper often 

 twice as long; sheaths slightly spreading at top; 1-2 in. long, 

 membranous when dry, the leaves grooved in the center and 

 stomatose on the edges, appearing 10-15 lobed by being connate 

 in 2 S and 3 S ; spike 2-3 long, an inch or less in diameter, consist- 

 ing of about 40 verticils of sporophyls. each verticil with about 

 as many sporophyls as the stem has ridges; sterile stems 6 -7 ft. 

 tall, X m diameter, white or pale green, naked below, 

 smooth, without stomata; internodes 1-3^ long; sheaths cylin- 

 drical, appressed, leaflets 10-40, narrow, 6-9 long; teeth half as 

 long, with short, firm, grooved, subulate centers and broad, fus- 

 cous, hyaline margins and tips, usually adherent in groups. 



Branches simple or rarely branched, without cavity, horizontal 

 or ascending, in verticils of 20-40, light green, stomatose, 4-5 

 angled, keels deeply grooved and downwardly roughened with 

 cross rows of toothed bands of silica; sheaths loose. 4-5 grooved, 

 the keels sulcate on the back, the commisural grooves lighter, 

 hyaline teeth short, erect; dried specimens marked with light 



