CHAPTER XVIII 
NARROW-LEAVED CHAIN-FERN 
Lorinseria areolata. 
Rootstock wide-creeping, forking, dark brown, at least when 
dried, furnished with light brown, concolorous, ovate, acute, 
entire scales: leaves scattered, distant or approximate, borne on 
all sides of rootstock; roots springing from rootstock, equalling 
or slightly exceeding the petioles in number. 
Leaves dimorphous, somewhat sensitive to frost; sporophylls 
erect, twelve to twenty-eight inches long; sterile leaves shorter. 
Petioles compressed at base, somewhat chaffy, bordered on 
each side for some distance from apex downward by a fine ridge: 
in sterile leaves longer to shorter than blades, slender, chestnut- 
brown below, often furrowed on face and sides, at least when 
dried, the lateral furrows containing the lateral ridges: in sporo- 
phylls stouter, elongate, rigid, light chestnut-brown to purplish- 
ebony, subterete: scales hyaline, ovate, acuminate, entire or 
subciliate, thinly clothing base of petiole, upper scales few and 
scattered or absent: fibrovascular bundle solitary, arched at 
back, more or less channelled on face. 
Blades of sterile leaves ovate-deltoid, below pinnate or sub- 
pinnate, above parted, gradually or abruptly narrowing to the 
often sinuate or sinuately lobed base of the ovate-lanceolate or 
