234 LASTREA FILTX-MAS. 



Lastrea FiLix-MAS, Prssl. — Partially deciduous, lying pros- 

 trate in winter; fronds lanceolate, bipinnate, attaining about five 

 feet in length; pinnse elongate-deltoid, pinnate; pinnules oval, 

 serrate, very slightly auricled, the lowest pair being rather longer 

 than the rest; indusium, when young, sub-peltate, (or like an 

 inverted soup-plate,) not embracing the spore-cases, partially 

 evanescent. 



Lastrea pseudo-mas, Wollaston. — Sub-evergreen, not pros- 

 trate in winter, coriaceous; fronds lanceolate, bipinnate, attaining 

 full five feet in length; pinna? elongate-deltoid, or pyramidal, 

 pinnate; pinnules paralleloid, or linear-obtuse, not auricled, 

 serratulate, the first anterior and posterior pair scarcely longer 

 than the rest; indusium, when young, embracing the spore-cases, 

 persistent, sub-rotund, depressed. 



Lastrea propinqua, Wollaston. — Deciduous, entirely sub- 

 alpine; fronds ovate-lanceolate, bipinnate, attaining but rarely 

 four feet in length; pinnae pinnate, pyramidal, inciso-lobate ; 

 pinnules biserrulate, crisped, strongly auricled, basal pair stipitate, 

 much longer than the rest; indusium embracing the spore-cases. 



There are several varieties belonging to these three species, 

 that it is doubtful at the present moment as to which species 

 to refer them; it has therefore been deemed the wisest course 

 to retain the whole under one head, namely, the original name, 

 Lastrea jilix-mas, special reference being made to such as have 

 been well determined as to the species to which they belong. 



Lastrea jilix-mas, in the widest acceptation, embracing L. 

 pseudo-rnas and L. propinqua, is found in almost every part 

 of Great Britain and Ireland: in some places the true L. 

 jilix-mas is the common form, whilst in others the L. propinqua 

 is more abundant. Each species has a number of varieties. 

 The well-known and beautiful multifid Fern known as L. 

 jilix-mas, var. cristata, does not belong to this species, but to 

 the L. propinqua of Wollaston. The L. jilix-mas abhreviata- 

 cristata of authors, is in reality L. pseudo-mas , var. cristata, 

 whilst L. jilix-mas, tar. Jcrcisii, belongs to the true L. jilix- 



