124 ART. 12. — K. YENDO. 



at a short distance from the base. Not infrequently we meet 

 with a form wliich has many unbranched stems starting multi- 

 cipitally from a prostrate disc. 



The stems of young shoots are cylindrical at the basalmost 

 j^ortion but soon become angulate above. In the middle portions 

 of fronds they are, as a rule, triquetrous, more or less twisted, 

 and occasionally complanated and ancipitous. The stems of the 

 lateral branches are filiform and cylindrical ; but in a well grown 

 individual their basal portions are minutely denticulated by the 

 scars of fallen leaves. The specific name comes probably from 

 this character. A good -sized frond measures 30-35 cm. in height, 

 with the lateral branches as long as 3-6 cm. 



The basal leaves are spathulate or lanceolate with a short, 

 complanated petiole. Those on the embryonal shoots are thick, 

 mostly entire or undulating at the margin; but those above a 

 short distance from the base are coreaceous, pinnately dentated, 

 and evidently retrofractive ; an elevated midrib runs almost to the 

 apex. The edges of the complanated petiole run upwards into the 

 ridges of the triquetrous stem and are often remarkably pronounced. 



The leaves on the lateral branches are linear, alternately 

 pinnately dentated, with a rib that runs undulating along the 

 median line. The laciniœ are more or less obliquely triangular, often, 

 however, linear-subulate or truncated, and not seldom duplicato- 

 serrated. The sini are round and deep reaching almost to the 

 rib. In the lower lateral branches the leaves are much smaller 

 and approximately disposed. In most cases no obvious subordinate 

 ramuli are seen on the lateral branches ; but if one develops to 

 any degree, the leaflets on it are linear-spathulate or clavate, 

 attenuated below into long petiole, subentire at the margin and 

 with an evident rib. 



