

ICONES FILICUM SINICARUM 



65 



PLATE 32. 



PTERIS DELTODON Baker 



POLYPODIACEAE 



* 



PTERIS DELTODON Baker in Journ. Bot. 26: 226 (1888); C. Chr. Ind. 596 (1906); Matthew 



in Journ. linn. Soc. 39: 389 (1911). 



Pteris nana Christ in C. Chr. Ind. 603 (1906). 



V Pteris trifoliata Christ in Bull. Boiss. 7: 7 (1899); Diels in Nat. Pfl. Fam. 1. 4. 292 (non 



Fee 1857). 



Rhizome short, erect, densely fibrous-rooted; stipes tufted (4-7), slender, naked, 

 shining straminous, 10-30 cm. long; frond deltoid-ovate, simply pinnate, of thick 

 coriaceous texture, 10-20 cm. long, green and glabrous on both sides; pinnae 3-5, with 

 the terminal one much the largest, oblong-ovate to broad lanceolate, 5-15 cm. long, 

 1.2-2.5 cm. broad in the middle, sessile except the terminal one, which is cuneate at 

 base and usually shortly petiolate, conspicuously inciso-dentate at the sterile tips, 

 which is acuminate in the terminal pinna, and usually acute in the lateral ones; veins 



m 



lax, branching at angles of 75° from the costa, simple or torked, very distinct; sori 

 continuous from the base up to within a short distance of the tip of pinnae, inducium 

 narrow, glabrous, dark-brown. 



■ 



Distribution: Szechwan, Kweichow, Yunnan, Kwangtung. 



This species is nearest to Pteris cretica L. from which differs in but fewer 

 pinnae, of which the lowest are simple, the serrations in sterile parts are also different 

 and further differs by laxer veins. The frond is generally trifoliate but larger forms 

 often have five leaflets with the lower pair separate from the one next above by a 

 wingless racbis about 1-2 cm. long. Pteris nana Christ from Yunnan is perfectly 

 identical with Baker's type from Omei Shan, Szechwan, differing only in somewhat 

 broader pinnae. A specimen, No. 8366, in Hongkong Herbarium from Kwangtung 

 (without precise locality) appears almost congeneric with the present species, differing 

 only by perfect entire sterile pinnae. Pteris nana Christ var. quiquefoliata Copel. from 

 Fukien, a plant larger than the type having lateral pinnae cleft at the base, should be 

 called P. deltodon Baker var. quiquefoliata (Copel.) Ching, if it does not represent a mere 

 vigorous form of P. cretica L. — R. C. C. 



Plate 32. Fig. i. Habit sketch (natural size). 2. A portion of fertile pinna, dorsal side (x 2). 

 3. A fertile pinna, ventral side (x 2). 



/ 



