—35— 



Hulst, bears fruit dots. Both varieties are cultivated, and four- 

 teen others have been enumerated from fern collections in Europe. 

 P. vulgarev2Lr. y ajigustiim Mull., was collected by me at Hancock, 

 N. Y., in 1874, and by Miss Vail at Onteorain 1891. It has long- 

 acuminate-serrate pinnas. A peculiarly narrow variety with short, 

 blunt pinnae occurs in the Black Hills at 5-6,000 feet elevation, 

 and has been determined by Mr. Rydberg as var. rotundatuvi 

 Milde. 



New York City. 



TUBERS OF NEPHROLEPIS. 



By J. Birkenhead. 



IN the January, 1S99, number of The Fern Bulletin this pecu- 

 liar and, so far as ferns are concerned, unusual mode of re- 

 production was referred to by your correspondent, Mrs. J. M. 

 Milligan. I am very doubtful about the fern referred to in this 

 lady's notes as bearing a number of corm-like growths, being N. 

 exaltata. During a thirty years' experience amongst ferns I have 

 never come across a plant of exaltata with tubers. Neither do I 

 find a reference by any authorities whose works I possess to the 

 tuber-bearing characteristic of this species. I am strongly in- 

 clined to believe that the fern referred to by your correspondent 

 is really N. tuberosa. Because, probably, of its erect growth this 

 fern is very frequently mistaken for exaltata, the latter species, 

 however, being quite distinct from the former, very much stronger 

 in growth and having broader and much more massive fronds. 

 Exaltata is frequently 5 to 6 inches in width of frond, more 

 glossy, more pointed in the pinme, and different from tuberosa in 

 its fructification. 



In addition to tuberosa there are several other Xephrolepis 

 which have this characteristic of producing tubers on their roots. 

 N. Philippinensis produces them in profusion; so also does 

 piuma, which is a deciduous kind; Bauseii, a very beautiful vari- 

 ety of the preceding, also deciduous; and undulata, likewise 

 deciduous. A peculiar feature about these deciduous kinds is that 

 the plant of one season does not always grow again from the old 

 caudex, but there is in many cases a tuber formed close to the old 

 caudex, from which growth commences in due course the follow- 

 ing season. The other tubers formed on the roots at various dis- 

 tances away from the main stem also commence growth and pro- 



