POLYSTICHUM ACROSTICHOIDES X ANGULARE. 



By Amedee Hans. 



Hybridizing plays a greater part in ferns than is 

 generally believed and many forms that are still 

 named species are only hybrids. This conclusion comes 

 to one when he sees how easily some species cross 

 when the spores are sown together. If Camptasorus 

 and Aspleniiim cbcncuni, though found in nature often 

 in different localities, can produce Asplenium cbcn- 

 oidcs by hybridization, there is no reason why others 

 could not do the same, especially in the tropics where 

 so many kinds grow together. 



The different forms of PoJystichum an gu I arc found 

 and raised in the British Islands, are among the finest 

 hardy ferns on account of the finely divided fronds of 

 some of them, but being entirely British forms, they 

 stand the climate of our Northern States only with 

 good protection. It occurred to me that by crossing 

 some of them with P olystichum acrostichoidcs some- 

 thing could be obtained that would combine the hardi- 

 ness of acrostichoidcs with the delicate cutting of some 

 of the forms of angularc. Accordingly I made sow- 

 ings of Polystichiim angularc venustum, P. a. divisi- 

 libatum, P. a. grand id ens, P. a. perserratum and P. 

 aculeatum Braunii. No crossing resulted from the 

 last sowing, but for the others the results were beyond 

 expectation. 



Of these sporelings, more than 1500 in num- 

 ber, more than 10% are distinct and all have passed 

 the past two winters without protection and without 

 loss, though during the first, they were only small 

 sjx trelings. Different forms of P. a. incisinn are the 

 most conspicuous. They are of different shapes, more 

 or less incised, undulate, recurved, crisped etc. The 



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