104 POLYPODIACEJE OF THE PHILIPPINE ISLANDS. 



Luzon, Cuming 41, 204; Isabela-Luzon, Warburg 11616; Benguet, Loher, 

 Elmer 6028; Lamao River, Copeland 242; Rizal, Ramos; Laguna, Loher; 

 Mindoro, Merrill 877; Masbate (?), Baranda; Paragua, Merrill 824a; 



Tropics, Africa across Polynesia. 



(43) HISTIOPTERIS Agavdh. 



Rhizome wide-creeping; stipe polished, stramineous to purplish; frond 

 bi-quadripinnatifid, lowest pinnules usually stipule-like; sori as in Pteris, 

 but commonly continuous around the sinus, and the spores bilateral instead 

 of tetrahedral. A genus of pantropic terrestrial ferns, usually all reduced 

 to a single species. 



(1) H. incisa (Thunb.) Agardh. Entire height commonly 2 in.; stipe 

 stout, erect, sometimes muricate toward the base; frond ovate or narrower, 

 bi-tripinnate; uppermost pinnae with entire oblong or linear-oblong pin- 

 nules ; those next below with numerous long, pinnatifid pinnules, the lowest 

 of which are close to the rachis and often adnate to it ; lowest pinnae often 

 very large, and quadripinnatifid, herbaceous or subcoriaceous, glabrous or 

 glaucous beneath; veins anastomosing to form several series of areolse, 

 free near the margin; sori interrupted, or continuous around the sinuses 

 .and apices of the segments. 



Luzon, Cuming 192; Baguio, Topping 239, Elmer 6007; Mount Mariveles. 

 Tropics and farther south. 



(2) H. montana Copeland. Rhizome beset with minute, brown palese; 

 stipe firm, 10 to 20 cm. high; frond 15 to 30 cm. high, often broader than 

 high, bi-tripinnatifid, lowest pinnae slightly larger than succeeding, very 

 coriaceous; veins prominent, raised above upper surface; indusia broad, 

 margin everywhere rolled in, giving segments a lomarioid appearance. 



Mount Apo, above 2,500 m.; DeVore and Hoover 332, Copeland 1049. 



(44) PTERIDIUM Gleditsch. 



Rhizome creeping, scaly; stipe with many flbro- vascular bundles; frond 

 at least bipinnate, deltoid; sorus on an intramarginal strand connecting 

 the ends of the veins, covered by an extrorse indusium, and this by the 

 inflexed margin of the frond; spores tetrahedral. A single polymorphous 

 species. 



(1) P. aquilinum (L.) Kuhn. Rhizome stout, wide-creeping, under- 

 ground; stipe 30 cm. or more high, strong, erect, naked, stramineous or 

 light brown; frond 60 to 100 cm. or more high, 30 to 60 cm. broad; upper- 

 most pinnae simple, the next pinnatifid, then pinnate ; the lowest the largest, 

 bipinnatifid or tripinnatifid, coriaceous, glabrous. 



Lepanto and Benguet, Loher. 



Cosmopolitan, chiefly northern. 



P. aquilinum var. lanuginosum Bory. Fronds evidently pubescent or 

 silky-tomentose beneath; pinnules more generally and regularly pinnatifid. 



Luzon, Cuming 24, 100; Bohol, Cuming 353. 



Cosmopolitan, chiefly tropical. 



Topping, No. 242, from Baguio is a mixture, perhaps including both 

 forms of this species. 



