138 



divided as the variety, and the pinnae and pinnulae are generally 

 more distant. It may include more than one form. 



D. spiNULOSA INTERMEDIA. Only One or two clumps were 

 found. Besides the characters ordinarily given, this variety may 

 be distinguished from the preceding in two respects. It matures 

 its sori a month or more earlier ; in this latitude, about the middle 

 or last of June. Its sporangia appear dark -brown or blackish, 

 as compared with the pale-brown sporangia of the so-called type 

 form. There seems to be some question whether the type form 

 really occurs in this country. A representative set of the species, 

 comprising our three recognized forms, was sent to Dr. Christ 

 of Basel, Switzerland, who identified all the specimens as D. spin- 

 ulosa exaltata, a European variety. This, however, was not 

 justified by the material. 



Is it not probable that we have included under this species a 

 complex of independent and mostly coordinate forms, corre- 

 sponding, perhaps, to the known varieties ; in other words, 

 elementary species ? Such forms as appear to intergrade might 

 be explained as crosses. A point in favor of this explanation is 

 found in the fact that not infrequently such intermediate forms 

 have only abortive sori and sporangia, a character nearly always 

 associated with the recognized hybrids of Dryopteris. 



D. CRiSTATA. Frequent, the commonest of the group. 



D. ClintOxMANA (D. C. Eaton) Dowell * {D. cristata Clin- 

 toniand). Distinguished from the preceding by its much broader 

 and larger fronds ; the sori, also, are much closer to the mid- 

 veins of the pinnulae. Several plants were seen. 



D. BooTTii. One group of vigorous plants. 



D. CRISTATA X marginalis. One group of strong plants with 

 hardly an abnormal frond. 



Cultural and field work is being carried on with the hope of 

 clearing up some of the points of difficulty regarding these 

 species and the writer would be glad to exchange material col- 

 lected in this locality and in central New York for specimens from 

 other sections. 



New York Botanical Garden. 



* Proc. Staten Is. Assoc, i : 64. My 1906. 



