THE YOUNG NATUEAUST. 



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indusia. Comprises Boreale only. 

 Blechnuni Boreale- or B. Spicant 



(Common Hard Fern). — It produces two 

 kinds of fronds, viz: — "fertile and barren." 

 The fertile ones grow erejt from the centre, : 

 and from 6 to 12 inches high ; the barren 

 ones grow from 3 to 8 inches high, and 

 assume a spreading condition. These fronds 

 grow in tufts, and are of a narrow lanceolate 

 form. The venation is more prominent on 

 the barren fronds. Sori are arranged in 

 two linear rows, becoming confluent. Found 

 in heathy and stony situations, and is very j 

 common. There are 5 varie ies. 



Sub-Group 5, Piaridea. 



Ferns whose sori arj marginal, and j 

 continuously and inter! uptedly changed . 

 into special indusia. 



Genus 10. Pteris. 



Pteris Aquilina (Common Brake Fern) 

 — This fern has a creel ing caudex, which 

 produces at intervals the fronds. They are 

 ovate-elongate, bipinnate, sometimes tripin- | 

 nate, and the pinnae are in pairs. The ; 

 stipes is downy while young, the under sur- 

 face being blackish in colour. Sori are well 

 distributed. Fronds spring up at the end of 

 May. Found all over the country where j 

 the conditions are suitable for its growth. 

 There is one variety only. 



Sup- Group 6, Acianteae. 



Ferns, the margin of " hose fronds bears • 

 reflexed lobes, which change to indusia, and 

 bear sporangia on the under surface. 

 Genus n, Adianttim. 



Dorsal-fruited ferns, having sporangia in 

 Batches, on the reflexed apices of the fronds, 

 which form indusia. Comprises Capillus- 

 Vcneris only. 



Adiantum Cap illus- Veneris (Maidem 



Hair Fern). — This beautiful ferngrows with a 

 creeping stem, and from 6 to 12 inches high. The 

 fronds are ovate elongate in form, bipinnate, 

 with alternate pinna and pinnules. The pinn- 

 ules are irregular, and fan-shaped. Venation is 

 distinct, the stipes is furnished with small j 

 scales, and the lower part is black. Sori are ob- I 



long, and covered by oblong indusia. Found in 

 cavernous and rocky situations, and is locally 

 distributed. There are 3 varieties. 



Sub-Groub 7, Cysiopterideas 



Ferns whose sori have ovate indusia fixed 

 behind the sori, and inflected over them. 

 Genus 12. Cysto pteris. 



Dorsal-fruited ferns having cucullate in- 

 dusia attached by their base. Comprises 

 Fragitts, Alpina, and Montana. 



Cystopteris Fragllis (Brittle Bladder 

 Fern) is a tufted growing plant, spreading 

 under conditions into large patches, and 

 grows from 6 to 12 inches high. Fronds are 

 lanceolate and bipinnate, the pinna lanceo- 

 late, and the pinnules ovate-acute. The 

 stipes is brittle and shining with a few scales 

 at the base. Sori are numerous, irregular, 

 and confluent: they are circular, and covered 

 by a concave indusium until cast off. Fronds 

 appear early in April. Found on w alls, and 

 in moist, rocky situations. There are 

 2 varieties. 



Cystopteris Alpina (Alpine Bladder 

 Fern). — Is a diminutive but elegant plant. 

 It produces from its tufted stem, fronds 

 from 4 to 8 inches high. Their form is 

 lanceolate, bipinnate, and the pinnules 

 tripinnate. The stipes is short, smooth, and 

 scaly at the base. The pinnas are nearly 

 opposite with blunt ovate pinnules, linear 

 lobes, and blunt teeth. The sori are numerous, 

 roundish, and covered by a concave indusium. 

 Fronds appear in May. Found on old walls, 

 but is very rare and local. 



Cystopteris Montana (Mountain 



Bladder Fern). — This fern grows with a 

 slender creeping stem. The fronds are from 

 6 to 8 inches high, and triangular in shape. 

 They are partly bipinnate, the pinna; 

 spreading, the inferior side being much larger 

 than the superior, the pinnules ovate — 

 lanceolate, and the margins toothed. Sori 

 are roundish, numerous, and covered by a 

 concave indusium. Found on mountains 

 (Scotland). 



(To be continued ). 



