448 PROCEEDINGS OP THE AMERICAN ACADEMY. 



which are genetically very distinct. Consequently, as stated, an attempt 

 has been made to get at a more satisfactory basis for classification by 

 studying the characteristics of the perigynia, which, naturally, are sub- 

 ject to less variation than is the superficial aspect of the inflorescence 

 as a whole. But since variations in texture and nerving, which are per- 

 fectly evident upon comparison of specimens, are extremely difficult to 

 render clear in descriptions, it has been found advisable to employ as 

 the primary basis of division, at least in the groups here discussed, the 

 actual or proportional measurements of the perigynia or the achenes. 

 Even this method of careful measurement may sometimes prove mislead- 

 ing, but in most species the perigynia vary within certain clearly defined 

 limits, and it is only the very exceptional individual which will not fit 

 the system here proposed. And, although in rare cases a species thus 

 presents perplexing forms in which the perigynia are not characteristic, 

 many attempts to classify the members of this group have convinced 

 the writer that by actual measurement alone can we safely identify 

 plants of such strong outward resemblance as Carex straminea, G. 

 scoparia and C. tenera, or C. alata and C. albolutescens. 



As a result of these studies it has been found desirable to treat many 

 plants in a manner somewhat different from that in any current synopses 

 of the genus, and in some cases a study of the original descriptions and 

 specimens has brought the writer to conclusions very different from 

 those generally accepted by American caricologists. Some of these 

 points are of slight significance, others of fundamental importance ; and, 

 since it is inadvisable to complicate the synoptic treatment of the species 

 with detailed discussions as to the identity and synonymy of different 

 forms, the more important questions may be here discussed. 



Carex scoparia, Schkuhr, presents little difficulty, as the original 

 figure is unmistakable. The species has, however, been made to harbor 

 plants of very different aspect ; and a study of the fruiting characters 

 shows these to fall into three groups with marked and constant char- 

 acteristics. C. scoparia, itself, has the perigynium very thin and scale- 

 like, with the wings so strongly developed as to minimize the apparent 

 thickness of the body. This plant in its different forms is of broad 

 range south and west of the Gulf of St. Lawrence. 



The other two species which have been included with Carex scoparia 

 have the narrower subulate or elongate-lanceolate perigynia so little 

 winged as quite to lack the scale-like character seen in that species. 

 The best known of these two plants is the form described by Francis 

 Boott as C. scoparia, var. minor. The material from which Boott's 



