ICONES FILICUM SINICARUM 



69 



PLATE 34 



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PTERIS DIMORPHA Copeland 



POLYPODIACEAE 



PTERIS DIMORPHA Copel, in Phil. Journ. Sci. Bot. 3 C: 282 (1908); C. Chr. Ind, Suppl. 



66 (1906-12); Matthew in Journ. Linn. Soc. 39: 389 (1911). 



' 



Rhizome short, ascending, about 4 mm. thick, densely fibrous-rooted, clad at the 



* 



apex in minute subulate castaneous scales; stipes shining, reddish towards the base, dark 

 straminous upward, narrowly winged on the uppermost part; frond strongly di- 

 morphous, the sterile ones 10-15 cm. long, the fertile 25-30 cm. long, the sterile oblong- 

 deltoid, tripartite, glabrous, of chartaceous texture, shining light green on both surfaces, 

 lateral pinnae ovate, falcate, to 5 cm. long, deeply incised, segments about 5 on each 

 side, close, oblong, obtuse, the terminal one much the largest, to 2 cm. long, sharply 

 serrate or subentire, the middle pinna the largest, to 10-15 cm. long and 3-4 cm. broad, 

 broad lanceolate, gradually acuminate, with 6-10 segments on each side, the lowest ones 

 reduced and narrowly decurrent along the rachis; fertile frond 10-15 cm. long (some- 

 times only 5 cm. long), pinnate like Pteris ensiformis Burm. with 1-2 pinnae on each side 

 under the terminal one, the lowest ones forked or simple, 6 mm. broad, all decurrent in 

 a narow wing, the terminal pinna the largest, to 10 cm. long, often irregularly pinnatifid; 

 inducium narrow, continuous to the blunt serrate apex, dark gray. 



Distribution: Kwangtung. 



This distinct and rather uniform species was first discovered by Dr. Charles G. 

 Matthew of the British Navy in the mountains in southeastern Kwangtung, and later in 



* 



1927 was collected in the mountains on North River by Prof. W. Y. Chun, of Botanical 

 Laboratory, Canton, whose copious materials have recently been received by me. The 

 specimens match the type very well, except that it show somewhat less dimorphism and 

 in this respect it may be well considered as an intermediate between P. multifida Poir 

 and P. ensiformis Burm. — R. C. C. 



Plate 34. Fig. 1. Habit sketch (natural size). 2. A portion of sterile segment, showing venation 

 and serration (x 4). 3. A portion of fertile segment, showing venation and inducium (x 4). 



