234 



Commercial Gardening 



appearance. The true S. denticulata, from the European Alps, is a slower- 

 growing kind than 8. Kraussiana, and is almost hardy. S. Emiliana 

 grows about 9 in. high, and S. Martensi and its variegated form are good 

 free-growing plants. S. Emiliana aurea is a golden form raised by Messrs. 

 J. Hill & Son. It is becoming one of the most popular for market work. 

 The same may be said of perelegans. 8. amcena, a variety of caulescens, 

 however, is the best of all, and is a very charming kind. Of the variegated 

 kinds, S. Watsoniana, with silvery- white shoots, is one of the best. 



Todea africana (or T. barbara). A bold and ornamental South African 

 Fern having a thickish bolelike stem and twice-pinnate fronds, 3-6 ft. long, 

 with serrated pinnae, and dense masses of reddish-brown spore clusters. It 



makes a compact plant when well 

 grown, and is a very useful Fern 

 for market work. It should be 

 grown in a close damp atmosphere 

 and shaded from the sun. T. 

 superba (fig. 317) is a charming 

 New Zealand Fern with grace- 

 fully spreading feathery-looking 

 fronds. It requires to be treated 

 as a Filmy Fern, described below. 



[A.J.H.] 



Woodsia. A genus of dwarf 

 tufted ferns with pinnate fronds 

 and roundish clusters of spore 

 cases. They may be grown in the 

 same way as the Hart's Tongue 

 Ferns, in moist and shaded spots. The best-known kinds are: hyperborea 

 (alpina), from the wet alpine rocks of North Wales and Scotland, having 

 tufts of lance-shaped fronds 3 to 6 in. long; ilvensis, closely related but 

 with broader fronds; obtusa, from North America, and polystichoides, from 

 Japan, are other species. 



Woodwardia. A genus with half a dozen species of ornamental Ferns 

 having large twice-pinnate fronds, and linear sori sunk in the cavities of 

 the fronds in single rows parallel with and contiguous to the midribs of 

 the pinnae and pinnules. The plants are hardy in the mildest parts of the 

 kingdom, but require greenhouse protection in other places. W. areolata 

 has fronds 6 to 12 in. long; and W. virginica about 6 in. longer, both kinds 

 from North America. W. japonica, with fronds 1 to 2 ft. long, and W. 

 orientalis, with fronds 4 to 8 ft. long, come from China and Japan. The 

 best-known kind, however, is W. radicans, from the northern subtropics. 

 It has graceful fronds 3 to 6 ft. long and 1 to 1| ft. broad, divided into 

 lance-shaped pinnae each of which is cut down almost to the midrib into 

 finely toothed pinnules. The variety cristata is beautifully and symmetri- 

 cally crested. 



Filmy Ferns, This name has been applied to various species belonging 



Fig. 317. Todea superba 



