86 



THE BOOK OF CHOICE FERNS. 



shar|)- pointed pinnules that are toothed on the margin. The sparingly - 

 produced sori (spore masses) are rather large and disposed mostly on the 

 lower half of the pinnules (leaiits), where they are mixed with ovate (egg- 

 shaped), conspicuously fringed scales ; they are covered by deep, cup-shaped 

 involucres, which break down at the margin and are somewhat persistent. — 

 Hooher, Synopsis Filicum, p. 21. 



C. meduUaris — med-ul-la'-ris (pithy), Swartz. 



This is a magnificent and deservedly popular greenhouse species ; it 

 cannot be mistaken, as no other known Tree Fern bears the slightest resem- 

 blance to it (see Plate). It is a native of New Zealand, Norfolk Island, and the 

 Pacific Islands, where, according to Lowe, the soft, pulpy substance which 

 occupies the centre of the trunk, and which somewhat resembles sago, forms 

 a common article of food ; it has also been found in the colony of Victoria, 

 by Baron Von Mueller. It is the most gigantic-growing species known in 

 the whole genus, and produces, in its native habitats, a trunk upwards of 40ft. 

 in height, bearing magnificent spreading fronds 12ffc. to 15ft. long and pro- 

 portionally broad, bi- or tripinnate (twice or three times divided to the 

 midrib), and of a leathery texture. These are borne on robust stalks, at first 

 of a peculiar prune-colour, but with age becoming jet-black and beautifully 

 polished. Before they are fully unfolded, the young fronds are densely clothed 

 with long, black, chafiy scales, which later on change to a bright, light 

 brown colour. In the fully-developed fronds, the stalks and also the midribs 

 are rough with hard, glandular tubercles of a glossy nature and resembling 

 a resinous exudation. The pinnaa (leaflets), fully 3ft. long, are divided into 

 secondary pinnae Sin. to Gin. long, about lin. broad, deeply pinnatificl (cleft 

 nearly to the midrib) or again pinnate ; these are again cut into pinnules 

 or segments of oblong or narrow-oblong shape, blunt, coarsely toothed in 

 barren fronds, lobed and pinnatifid in the fertile ones, with the margins 

 turned back. The sori (spore masses), abundantly produced and orange- 

 yellow in colour, are disposed one to each lobule of the pinnule or lobe, and 

 are situated about midway between the midvein and the margin ; they are 

 covered by circular involucres of parchment-hke texture, which soon break 

 open at the summit with an irregular, often two-lobed margin. The whole 

 surface of the frond is of a most pleasing, bright green colour. — Hooker, 



