252 
THE FERNS OF SOUTH AFRICA 
Genus 34. Pteris Linn. 
Indusium marginal, continuous, opening inward, and 
bearing the capsules in an uninterrupted, narrow line, along 
its axil. Veins free or nearly so. This large genus con- 
tains plants of various habit, and has been split into several 
genera by some authors, while others keep it entire, or unite 
Pellaea and Lonchitis with it. Several species are widely 
distributed, and others are found all over the world. 
Key to the species : 
141. P. longifolia. Frond simply pinnate. 
142. P. cretica . Pinnae linear* the lower with one or two linear 
pinnules on the lower side. 
143. P. dentata. Two to three- pinnate, barren pinnules distinctly 
serrate. 
144. P.biaiirita. Frond two to three-pinnate, barren pinnules not 
toothed, or only very slightly. Veins usually free. 
145. P, brevisora.- Frond three-partite, i.e. having one central and 
two side pinnae, each with numerous pinnate pinnules. 
146. P. Buchanani. Frond two to three-pinnate, barren pinnules 
distinctly serrate. Veins united in one line of areolae on each side 
of the mid-rib. 
147. P. atrovirens. Like P. biaurita , but with prickly stems and 
anastomosing venation. 
141. Pteris longifolia Linn. 
Plate 125. Nat. size. 
Rhizome procumbent or shortly creeping, paleaceous. 
Frond simply pinnate, lanceolate, one to three feet long, 
three to eight inches broad, glabrous, and with a glabrous, 
green, channelled rachis,- and a short, round, herbaceous stipe, 
set with numerous, linear, white, spreading scales, toward the 
base. Pinnae about twenty pairs, three to four lines broad, 
two to four inches long about the middle of the frond, con- 
siderably reduced downward, and slightly reduced upward ; 
and the frond rather abruptly terminating in a terminal 
pinna similar to the others but longer ; all linear pointed, 
from a wide, rounded or cordate, sessile base, and serrate 
when not fertile. Indusium narrow, herbaceous in texture 
