farwell: genus hippochaete in north AMERICA 465 



Stems normally branched; branches spike 



bearing. H. prealta var. Siiksdorfi. 



Sheaths more or less ampliate and loose, but 

 not campanulate. 

 Teeth caducous. H. prealta var. intermedia. 



Teeth deciduous or persistent. H. prealta var. scabrella. 



Stems annual, spikes obtuse or apiculate, ridges rounded 

 (Ambigua). 

 Sheaths cylindrical, tight; teeth persistent. H. Nelsoni. 



Sheaths campanulate and loose; teeth caducous. 



Stems smooth to the touch. H. laevigata. 



Stems rough, simple. 



Bases of teeth straight. H. laevigata var. Eatonii. 



Bases of teeth, incurved. H. laevigata var. Funstoni. 



Stem rough, branched. H. laevigata var. polystachya. 



Hippochaete hyemalis var. californica (Milde) comb. nov. 



Equisetum hyemale var. calijornicum Milde; A. A. Eaton, Fern 

 Bull. 11: 113. 1903, as to the biangulate plants only. 



Equisetum hiemale var. Doellii Milde; A. A. Eaton, Fern Bull. 

 11:114. 1903. Not Milde, 1863. 



Typical H. hyemalis with caducous teeth has never been col- 

 lected in America. The Pacific coast plants differ in having the 

 teeth deciduous or more or less persistent. The plants referred 

 by Mr. Eaton to the var. Doellii Milde cannot belong there as that 

 European variety has the centrum only one fourth or one third 

 the diameter of the stem, while the British Columbia plants have 

 a centrum four fifths the diameter of the stem and the teeth are 

 not wholly persistent as described, at least on specimens distri- 

 buted which show them to be generally deciduous. California to 

 British Columbia. 



Hippochaete hyemalis var. Jesupi (A. A. Eaton) comb. nov. 



Equisetum variegatum var. Jesupi A. A. Eaton, Fern Bull. 12: 

 24. 1904. 



This variety has some of the characters of H. variegata, towards 

 which it trends. The teeth have long, generally persistent awns 

 and the anatomy is variable, sometimes of one type, sometimes 

 of the other. The size and aspect are intermediate but the tight, 

 cylindrical sheaths place it with H. hyemalis rather than with 

 H. variegata. 

 Belle Isle, Mich., Farwell 211a, June 4, 1895; Rochester, Mich., 



Farwell 211b July 4, 1896. Mr. C. K. Dodge has collected it 



at Port Huron, Mich. Its general distribution is from Illinois 



to Connecticut, northward into Canada. 

 31 



