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the fertile grow more rapidly. The spores mature early, after 

 which the spike decays and the remaining portion of the stem 

 becomes like the sterile in appearance. Probably the 15th of May 

 is a fair average time for the fertile stems, but the sterile do not 

 mature till a month later. 



VARIETIES. 



This species presents no very well-marked varieties, most 

 differences noted being degrees of development directly traceable 

 to environment. Most striking forms of any species receive names 

 and the residue is apt to be looked at as the type. This is not the 

 true light in which to consider the question, for obvious reasons, 

 unless we adopt the view that all the forms are necessary to con- 

 stitute the species, when the type is apt to sink into secondary 

 rank. Of the named varieties we appear to have seven, two of the 

 fertile stems and five of the sterile, as follows: 



1. Prcecox Milde. Fertile stem fuscous and naked at first, 

 later becoming green and branched. Found usually in open pas- 

 tures by water courses. This appears in its earliest stages like 

 E. arvense, but the long, thin ventricose sheaths easily distin- 

 guish it. Rarely a stem of this variety fails to put forth branches 

 at all, and then soon perishes. I have seen them with one very 

 small branch. From this they vary up to the normal form, in 

 which, however, the branches appear before the spikes mature. 



2. Serotinum Milde. Stems usually small, with 6-8 verticils 

 of recurved branches and terminated by a very small spike, of 4-6 

 rows of sporophylls. A transformed, sterile stem, corresponding 

 to the variety campestre microstachya of E. arveuse. Ascribed 

 to Labrador by Milde, who says it is rare. I find it not uncom- 

 mon in open pastures, where special search is made for it, and it 

 is occasionally found even in rich moist woods, where the stem is 

 taller and often curved at top, as in normal sterile stems. It ap- 

 pears to be absent from some localities, nevertheless. Most com- 

 mon in firm, grassy soil. 



3. Robustum Milde. Stem yellowish, erect, rigid, naked 

 below; branches arched and ascending, with short secondary 

 branchlets, which in turn bear a few short branchlets. This form 

 grows in sunny fields, its rigid habit and ascending branches being 

 due to direct sunlight. It is often found also in recent clearings. 

 Not always of large size. 



4. Capillars Hoffm. Stem 1-2 l 2 feet tall, erect, with recurv- 

 ing apex ; branches and branchlets capillary, horizontal spreading, 



