HISTORICAL INTRODUCTION. 7 



follow Moore (1857) and most recent scholars in accepting- the name Denn- 

 stcedtia punctilobula (Michx.) Moore. 



Two varieties of D. punctilobula have been described in recent years. 

 Dennst&dtia punctilobula var. cristata Maxon (1899) was found in Massa- 

 chusetts by F. G. Floyd. Under cultivation the percentage of crested 

 fronds produced varies greatly. "Some fronds have not only had the 

 apex of every pinna doubly or trebly crested, but the apex of the frond 

 itself has frequently been bifidly divided with heavily crested apices" 

 (Davenport, 1905) . I have several times seen fronds with the rachis bifur- 

 cated 10 cm. or more below the apex. Each fork, then, bears a normal 

 continuation of the leaf. Waters (1903) considers this condition "fre- 

 quent." He also states (p. 289) that "A form with rather narrow fronds, 

 the pinnae unequal in length and with the teeth of the ultimate segments 

 very deeply cut, so that each vein forms the midrib of a narrow tongue- 

 like segment, has been named D. pilosiuscula schizophylla. ' ' Of course this 

 name should read Dennsttedtia punctilobula schizophylla. On the relation 

 of these varieties to the typical form I have no opinion to express. 



In botanical literature other than taxonomic or noristic the hay-scented 

 fern scarcely appears. Descriptions of its habit of growth, its glands, and 

 long, slender rhizome are given by Williamson (1878, p. 117, plates XLV, 

 XLVI), Eaton (1879-1880, pp. 341-343, plate 44), Clute (1901, pp. 225-231), 

 and Waters (1903, pp. 288-290). Frances Wilson writes an appreciative 

 general account of these features in the Asa Gray Bulletin (1897), and 

 Waters (1903) adds to a pleasing text photographs which are exquisite 

 and true to life. Parsons (1899) and Eastman (1904) refer to this fern in 

 a popular way. 



Eaton (1879-1880) and Waters (1903) speak of the concentric arrange- 

 ment of light and dark tissues in the rhizome (cf. fig. 67), and the tax- 

 onomic writers tell of the indusium in detail. De Bary (1884) describes 

 the vascular bundle of Dennst&dtia (naming this species along with three 

 others in parenthesis) as having a tubular bundle, "which is closed as far 

 as the foliar gap; the bundle which enters the leaf arises from the whole 

 margin of the gap as a continuous concave plate \_cf. fig. 82], which is 

 only occasionally split up at its base into several bundles lying side by 

 side." Gwynne-Vaughan in 1901 (p. 85) mentioned the present species as 

 showing thick- walled elements in the phloem of the petiole. In 1903 

 (p. 691) he includes D. punctilobula in a list of nineteen ferns with typ- 

 ical and practically identical solenostelic structure, as described by him 

 in Loxosoma cunninghamii. A page of text is devoted to a summary of 

 the facts of structure in the group. A summary of taxonomic literature, 

 with synonymy, is given on our pages 44 and 45 following. 



