114 THE AMERICAN BOTANIST 



discoverer, we may call this domesticated fern Pettiford's 

 shield fern for purposes of introduction and general discus- 

 sion. 



Mr. Pilling has found among the nurserymen of the vicin- 

 ity a "commercial" fern somewhat similar to his specimen 

 bearing the name of Aspidium znridesccns but it has none of 

 the vigor and beauty of the plant growing in the Schuylkill 

 wild garden. The nurseryman's fern appears, in comparsion 

 with the domesticated specimen, to be drawfed and stunted 

 in growth so that the casual observer would not recognize the 

 two to be of a common origin. One is artificial, the other 

 natural. The oriental variety is a species of eastern Asia ex- 

 tending from Tonkin to Japan. Diels lists it as Polystichum 

 laser pctiifolhnn, but Christiansen takes up the earlier name 

 of Moore's and calls it Polystrichum Standishii (Moore) C. 

 Chr. It was transferred to Dryoptcris by Otto Kuntze in 

 1891 and is in fact, one of the comparatively few species ex- 

 actly intermediate between these two genera, in this respect re- 

 sembling Dryopterris denticidata (Swartz) Kuntze of tropi- 

 cal America which is often placed in Polystichum. 



In habit the plant is somewhat polystichoid and for that 

 matter the indusium also suggests Polysfichiiiii although it is 

 actually orbicular-reniform and attached distinctly to the 

 sinus rather than being centrally peltate. The fern is a hand- 

 some one in cultivation and in pursuit of the new policy of 

 the American Fern Society to fep.ture exotic ferns, we com- 

 mend this splendid plant to their early consideration. 



