288 THE TASMANIAN FLORA. 



18. POLYSTICHUM. 

 Sori discoid. Indusium peltate, attached by the centre. Leaves 2-3 times 

 divided. 



Tufted, middle primary pinnules longest I. P. vestitum. 



Creeping, lowest primary pinnules longest 2. P. coriaceum. 



1. P. VESTITUM, Pred. Tufted, 2-4 feet high. Leaves covered at the base with 

 coarse scales, bipinnate, not spreading. Ultimate pinnules obtuse or nearly so, 

 vaguely obtusely toothed, often bulb-bearing. Often referred to Aspidium 

 aeukatum, Swartz., of the Northern Hemisphere, to which it is very closely 



allied. 



Very common. All temperate parts of Southern Hemisphere. 



2. P. CORIACEUM, ScA. Creeping on dead wood and stones. Leaves erect, 8-18 

 inches, stiff, lowest pinnules 3-5 inches. Ultimate pinnules obtusely lobed or 

 toothed. Aspidium capense, Willd. ; Aspidium coriarmm, Swartz. 



Common in woods. Victoria, New South Wales, Asia, Africa, America, New 

 Zealand. 



19. CYSTOPTERIS. 

 Sori small, on the back of the leaf, protected by pocket-like indusium. 



C. FRAGiLis, Bern. Small, tufted. Leaf 3-5 inches, twice divided.* Ultimate 

 pinnules oblong, pointed, obtusely toothed. 



Wet rooks at Lake St. Clair, Middlesex Plains. Most temperate climates, 

 including New Zealand, but not in Australia. 



20. DJCKSONIA. 



Sori small, marginal, possessing an indusium and opening' outwards, but the 

 loaf -margin recurves, turning the sorus over the -indusium. 



D. ANTARCTICA, Lab. Tall tree-fern. Leaves long, broadly lanceolate, many 

 times divided, not long persistent after dying. Ultimate pinnules obtusely and 

 vaguely toothed. D. hillardieri, F. v. M. 



Very common. Extra-tropical Australia to New Zealand. 



21. DAVALLIA. 



Sori on the margin, small, covered by a pocket-shaped indusium, opening 

 outwards. 



D. DUBIA, R. Br. Creeping. Leaves pale, 1-2 feet, much-divided, broad. 

 Ultimate pinnules rather narrow, lobed or segmented. Indusium small and 

 delicate, soon covered and hidden by the sorus, which then appears free from the 

 margin and naked. Dicksonia dubia, Gaud. 



Common in north-west to George's Bay. Victoria, New South Wales, 

 Queensland. 



22. CYATHEA. 



Sori on the back of the leaf covered by a hemispherical indusium, which 

 ruptures in the centre, leaving a cup-like annulus below and surrounding the 

 soms. 



C. CUNNINGHAMI, jEf. Leaves very long, much-divided. Ultimate pinnules 

 narrow, minutely toothed. Stem very tall, 20-50 feet, slender. C. medullaris, 

 Swtz. (in error). 



Table Cape, Esperance, Geeveston, Long Bay, Tasman Peninsula, &c. 



23. ALSOPHILA. 

 Sori miinute, round, naked on the back of the leaf. 



