PTERIS. 255 



EuPTERis (Eup'-ter-is), or true Pteris, Llnnceus. This sub-genus is the 

 most extensive of the whole genus, and embraces : Plants with simply- 

 pinnate fronds {e.g., P. longifolia) ; plants having their lower leaflets forked 

 or slightly pinnate below, with a long, narrow, entire terminal leaflet {e.g., 

 P. serrulata) ; plants with their lowest leaflets again pinnate {e.g., P. 

 mutilata) ; plants with their lowest leaflets at least bipinnatifid, or twice 

 divided nearly to the midrib {e.g., P. quadriaurita) ; and plants with their 

 lowest leaflets much larger than the others, often nearly equalling the central 

 portion of the frond, (e.7., P. longipes). The species in this sub-genus have 

 all their veins free. 



Heterophlebium (Het-er-oph-leb'-i-um), Fee. The few plants comprised 

 in this sub-genus have their veins free below, but intercrossing each other 

 towards the margin. 



LiTOBEOCHiA (Li-tob-roch'-i-a), Presl. This somewhat extensive sub- 

 genus is composed of plants having the same habit as Eupteris, but with veins 

 copiously intercrossing each other and without free veinlets. 



PiESiA (Pass'-i-a), St. Hilaire. According to strict technical characters, 

 this sub-genus, also known as Ornithopteris of Agardh, which differs 

 from the rest of the genus in habit of growth, has as good a claim to be 

 placed in Liiidsayce as Pteridece. The fronds are produced from a creeping 

 rhizome, upon which they are distantly placed ; their veins are free, and 

 they are furnished with an involucre of a more or less distinctly double 



nature. 



The geographical distribution of the genus Pteris is as extensive as that 

 of any other, these useful plants being found in many parts of the Old 

 and New Worlds alike. While Europe produces such popular species as 

 P. aquiUna, P. arguta, P. cretlca, and P. longifolia. Tropical America supplies 

 us with P. chilensis, P. coriacea, P. laciniata, P. palmata, P. pidchra, 

 P. sagittifolia, &c. Again, we have in P. macilenta, P. scaberula, and 

 P. tremula three most distinct plants native of New Zealand, though the 

 last-named is also found wild in Australia and in company with the equally 

 distinct and no less beautiful P. liicisa and P. umbrosa. Tropical Africa and 

 Japan come in for their share in the distribution of Pteris, the latter country 

 giving us P. semipinnata, P. serrulata, P. Wallichiana, &c., while from the 

 former we have P. hiaurita, P. flahellata, P. marglnata, P. quadriaurita, &c., 



