138 REPORT OF NEW JERSEY STATE MUSEUM. 

 Key to the Species. 



a. Stems smooth, annual. 



b. Cone-like spike containing the sporanges, on a separate plant, pale 

 brown and witliout branches, appearing in spring and soon perishing. 

 Sterile green plant with numerous branches becoming at least 75 mm. 

 long. E. arvense, p. 138 



bh. Cone-like spike at the tip of the stem of a green branched plant, 

 branches fewer and variable, mostly less than 50 mm. long. 



B. ftuviatile, p. 138 

 aa. Stems harsh, stiff and evergreen, simple (very rarely branched). 



B. hyemale afUne, p. 138 



EQUISETUM L. 



Equisetum arvense L. Field Horsetail. 



Equisetum arvense Linnaeus, Sp. P. 1061. 1753 [Europe]. — Knieskern 40. — 

 Britton 312. 



Frequent except in the Pine Barrens, but mostly as a weed 

 along railroads, etc. 



Spores Mature. — Early April to late April, more rarely to 

 early May. 



Middle District. — Farmingdale, New Egypt, Kirkwood, Delanco, Medford 

 (S), Albion, Swedesboro (CDL). 



Coast Strip. — Forked River, Barnegat City (L). 



Cape A/ai'.— Dennisville (OHB), Court House, Anglesea Jnc. (S), Cape 

 May (OHB). 



Equisetum fluviatiie L. Swamp Horsetail. 



Equisetum fluviatiie Linnaeus, Sp. PI. 1062. 1753 [Europe]. 

 Equisetum limosum Britton, Cat. N. J. Plants 3^3- 



Open wet swamps in north Jersey and occasional in the Mid- 

 dle district close to the Delaware River. 

 Spores Mature. — Mid-May to early June. 

 Middle District.— Delaire, Kaighns Pt., Gloucester. 



Equisetum hyemale affine (Engelm.). Scouring Rush. 



Equisetum robustum afUne Englemann, Amer. Jour. Sci. 46:88. 1844 [St. 



Louis, Mo.]. 

 Equisetum hyemale Knieskern 40. — Britton 313. 



* E. scirpoides is given in Torre^s Catalogue 17, on the authority of Dr. 

 Eddy, as occurring in the New Jersey Pine Barrens, but there must have 

 been some mistake, as this species has never been found by anyone else. 



