BEAUTIFUL FERNS. 
157 
and consists of from four to ten pairs of appressed fleshy or 
cartilaginous pinnae, which are divided into a double row of 
sub-globose bead-like segments or pinnules ; the whole looking 
like a small and narrow but dense cluster of diminutive grapes. 
Each pinnule has its edges so much recurved that the whole 
forms a sort of pouch, apparently filled with sporangia. 
Mr. Faxon has made a careful study of the sori, and 
has very kindly furnished the account given below,' 
The articulations of the sporangia are said by Fee to 
be twenty-eight to thirty-two, and more numerous than in any 
other fern. I have counted only thirty at most, and more fre- 
quently only twenty-eight. The spores are ovoid and very 
dark-colored. 
Var. obtusilobata, Torrey, FI. New York, ii., p. 499, t. clx 
{Onoclea obtusilobata, Schkuhr), is not a permanent variation 
of the species, but is based on a not infrequent condition of 
the plant, in which the pinnae of some of the foliaceous fronds 
become deeply pinnatifid into obovate segments, which have 
mostly free veins and imperfectly developed sori. The indusia 
“ ' In O. senslbilis the sori are borne on the middle of the vein, and consist of a 
tough cylindrical receptacle, three or four diameters in height, bearing sporangia thickly 
all over its surface, and covered when young by a delicate hood-like indusium, attached 
half-way or more around the base of the receptacle on the inferior side, and having the 
crenulate-margined opening toward the apex of the segment. At an early stage the 
blackberry-shaped sorus is almost entirely covered by the indusium, which resembles a 
closely drawn cowl, but with the growth of the sporangia it is thrown back, or rent, and 
soon disappears, the sori becoming confluent. The receptacle is very persistent, and may 
be seen, covered with the stalks of the sporangia, in the dried last-year’s fertile fronds, 
which are always found where the plant grows.” 
