Pteridaceae 



41 



long, 5-15 cm. wide; pinnules thinly herbaceous to mem- 

 branous, oblong-ovate, 1-3 cm. long, 4-12 mm. wide, obtuse, 

 sessile, pinnately lobed to parted, often toothed, green above, 

 paler beneath, the lobes spreading, ovate, obtuse to rounded; 

 veinlets reaching the tip of the teeth; sori intramarginal, naked, 

 rounded, 1-1.5 mm. across, yellow-brown, often covered by the 



slighdy recurved tooth of the pinnules. Hills and low 



mountains; Honshu (Ugo and Rikuzen Prov. southw.), Shi- 



koku, Kyushu. Pantropic, also in Korea, Ryukyus, For- 

 mosa, and China. 



Hypolepis bamleriana Rosenst. Shima-iwa-hime-warabi. 

 A larger plant, 1.5-2 m. high with stout stipes often 1.2 cm. 

 in diameter; lowest pinna much larger and broader than the 



others. Recorded from Kyushu (Yakushima). New 



Guinea and Bonin Isls. 



7. PTERIDIUM Scop. 



Warabi Zoku 



Terrestrial; rhizomes long-creeping, solenostelic, with jointed hairs; fronds pinnately compound, coriaceous to thick- 

 herbaceous, more or less hairy; veins free except for a marginal strand; sori continuous along the margin, on a connecting 

 vein; indusium double; the outer one false, formed by the reflexed margin of the pinnules, the inner one distinct or obsolete. 

 A single cosmopolitan species with several geographically distinct variants. 



1. Pteridium aguilinum (L.) Kuhn var. latiusculum 



(Desv.) Underw. Pteris lanuginosa Spreng.; Pteris sprengelii 

 Steud.; Pteris latiuscida Desv.; Pteridium latiusculum (Desv.) 

 Hieron.; Pteridium aquilinum var. japonicum Nakai; P. aqui- 



linum sensu auct. Japon., non Kuhn Warabi. Fronds 



coarse, deciduous; rhizomes long-creeping, terete, 4-5 mm. 

 across, remotely leafy, usually with pale brown jointed hairs at 

 the tip; sdpes 20-80 cm. long, rather stout, pale green, glabrous 

 above, with soft hairs at the dark brownish base; blades 

 broadly ovate-triangular, 20-100 cm. long, 17-70 cm. wide, 

 short-acuminate, green above, slighdy paler beneath, usually 

 ternate-pinnate, the rachis sulcate and pubescent on upper side 

 especially in the axils at base of pinnae, pale green; pinnae of 



the lowest pair manifestly larger than the others, reaching 2/3 

 of the entire length of the blade, spreading, 2- to 4-pinnati- 

 parted, triangular-ovate, acuminate; pinnules subcoriaceous to 

 thick-chartaceous, horizontally spreading, straight, oblong to 

 linear-lanceolate, 3-6 mm. wide in the fertile, 5-8 mm. wide in 

 the sterile ones, obtuse, usually glabrous above, thinly white- 

 pilose at least along the costas beneath, slighdy recurved on 

 margins; sori marginal, conunuous; indusia scarious, glabrous 



or nearly so, narrow. Aug.-Oct. Sunny slopes in hills and 



mountains; Hokkaido, Honshu, Shikoku, Kyushu; very com- 

 mon. Ryukyus, China, Korea, Sakhalin, s. Kuriles, Kam- 

 chatka to Europe, and e. N. America. 



8. HISTIOPTERIS J. Smith Yunomine-shida Zoku 



Terrestrial; rhizomes long-creeping, solenostelic, with narrow dark brown hairlike scales; fronds usually large, glabrous; 

 pinnae chartaceous to coriaceous, opposite, usually sessile, often glaucous, with stipulelike basal pinnules; veins anastomosing 

 without included veinlets; sori continuous along a marginal connecting vein, covered by a scarious reflexed false indusium, 

 freely paraphysate. Pantropic, with about 7 species. 



1. Histiopteris incisa (Thunb.) J. Smith. Pteris incisa 



Thunb.; P. aurita Bl. Yunomine-shida. Fronds large, 



glabrous, evergreen; rhizomes creeping, remotely leaved, 4-7 

 mm. across, with dark brown lustrous jointed crisped hairs; 

 stipes shorter than the blades, lustrous, dark purple-brown at 

 least on the lower half, 5-15 mm. across; blades large, to 1 m. 

 long, triangular-ovate, obtuse to short-acute, glabrous, green 

 above, glaucous beneath, bipinnate or bipinnatiparted, the 

 rachis terete, brownish or stramineous; pinnae opposite, 5-10 



pairs, nearly horizontally spreading, broadly lanceolate to ob- 

 long-ovate, acute with an obtuse tip, sessile, pinnatiparted to 

 pinnate, in large fronds the lowest pair of pinnules much 

 reduced and stipulelike; ultimate pinnules opposite, narrowly 

 ovate to elliptic, 5-20 mm. wide, obtuse to rounded, horizon- 

 tally spreading, entire or sinuately lobed; veins anastomosing 

 slender; sori marginal, elongate, covered by the reflexed mar- 

 ginal false indusium. Honshu (Izu and Kii Prov.), Kyu- 

 shu; rare. Pantropic. 



9. PTERIS L. I-No-MoTo-so Zoku 



Terrestrial; rhizomes short, dictyostelic, scaly or sometimes hairy; fronds herbaceous to coriaceous or chartaceous, tufted, 

 pinnate to decompound, glabrous or rarely hairy; veins free except in the sori, or anastomosing without included veinlets; 

 sori continuous along the margin except at the apex and in the sinuses of the pinnules, covered by the scarious refle.xed margin 



of the segments, with paraphyses among the sporangia. About 280 species, nearly all tropical, some in New Zealand, 



Tasmania, S. Africa, Japan, Europe, and the United States. 



LA. Ultimate divisions of blades linear, unlobed; rachis and costas without spines on upper side. 



2.\. Blades narrowed at base; stipes prominendy brown-scaly I. P. viltata 



2B. Blades not narrowed at base; stipes smooth or nearly so. 



3A. Upper pinnae dccurrent on the rachis; sterile pinnae 6—12 mm. wide 2. P. miillifida 



3B. Upper pinnae not decurrent on the rachis. 

 •4 A. Sterile pinnae 8-25 mm. wide. 



5A. Fronds nearly all alike; sterile pinnae linear-lanceolate, 10-25 cm. long, 1-2.5 cm. wide, acuminate 3. P. cretica 



5B. Fronds dimorphic; sterile pinnae lanceolate to oblong-ovate, 1.5-10 cm. long, 7-12 mm. wide, obtuse 4. P. ryukyuensis 



4B. Sterile pinnae linear, 3-20 cm. long, 3-6 mm. wide 5. P. yamatensis 



