12 



Polypodium Dryopteris, Linrueus. Polystichum Dryopteris, Roth. 

 Lastrea Dryopteris, Newman. Gymnocarpium Dryopteris, 

 Newm. Hist. Brit. Ferns, 57. 



Not unfrequent in dry stony woods and shady rocky places in 

 the mountainous parts of the north of England, and in Wales and 

 Scotland ; often very luxuriant about waterfalls, where it is kept 

 constantly moistened by the spray, but rarely in this case producing 

 fructification. The rhizoma, very slender, often almost filiform, 

 spreads widely, forming, with its complicated branches and dark- 

 coloured radicles, a dense turf-like mass. The fronds spring up 

 in April, and present a remarkable form of vernation, the three 

 branches being separately coiled, so as to resemble, as observed 

 first by Mr. Newman, three little balls supported on slender wires. 

 In maturity they vary from three or four inches to a foot in height, are 

 of a pale bright green, perfectly smooth, and supported by an erect, 

 very slender brittle stalk or rachis, clothed with a few scales at the 

 base. A general tendency to droop is characteristic of the whole of 

 the leafy portion of this delicate fern, affepting not only the primary 

 branches, but giving a striking convexity to all of the segments, a 

 circumstance well expressed in our figure. The fronds are mostly 

 barren ; the fertile ones rise higher than the others, and are farther 

 distinguished by the comparative narrowness of their segments. 

 The lateral veins of the segments are generally branched, and, 

 where fertile, the sori are produced near the extremity of the upper- 

 most branches ; in luxuriant specimens their regular arrangement 

 is often disturbed by development from some of the other branches 

 of the vein. Fructification in June and July. 



In cultivation, shade is even more essential t</ this species than 

 to the preceding. Next to the delicacy of texture and graceful 

 habit, the vivid green hue of the foliage constitutes its principal 

 beauty, and this latter is entirely lost by exposure to direct sun- 

 light. Abundant moisture, though recommended by many, is so 

 far from being necessary to its flourishing condition, that, unless 

 drainage is at the same time complete, it will soon destroy the 

 plant by causing the decay of the rhizoma. Attention to these 

 circumstances will ensure the fact, that one of the most elegant 

 and beautiful of our smaller ferns is likewise one of the most free 

 growers and most easily kept. 



POLYPODIUM CALCAREUM. Rigid three-branched Polypody. 

 TAB. IV. 



Fronds triangular, subtcrnate, erect, glandular; branches pin- 

 nate ; pinnae of the lower ones piiwiatifid, with obtuse segments, 

 those of the upper branch nearly entire. Sori marginal. 



