Carse. — Ferns and Fern Allies of Mangonui County. 83 



common form is bulbiferous, and closely resembles some forms of A. bulbi- 

 ferum : another is very like a slender form of A. hiciihnn. 



A. umbrosum J. Sm. is plentiful in moist shaded places. Its stout 

 fleshy rhizome enables it to linger for years on alluvial flats after the forest 

 has been cleared ; so persistent is it, in fact, that it becomes a weed. The 

 fronds are rather delicate, and blacken at the first frost. 



A. japonicum Thunb. : This fern is plentiful in alluvial soil in the 

 immediate neighbourhood of Kaiaka, and occurs here and there along the 

 river-bank in the Kaitaia district. 



It is by no means a common plant in New Zealand. It was. I believe, 

 first noted in the Dominion on the Okura Creek (Bay of Islands) ; later 

 I reported it from Kaitaia ; and since then it has been found on the 

 Northern Wairoa River. It grows best in low-lying alluvial woods. 



* 



19. Aspidium Swartz. 



Seven species are listed in the Manual, two only of which grow in this 

 district. 



A. Richardii Hook, is usually found among rocks, maritime and inland. 

 It varies considerably as to the extent to which the pinnae are divided, 

 and the shape and toothing of the pinnules. As might be expected, forms 

 growing on exposed rocks, maritime or inland, are more coriaceous in 

 texture, and have shorter and blunter pinnules, than those whose habitat 

 is more favourable. 



A. adiantiforme (Forst.) J. Sm. is, in my opinion, one of the most hand- 

 some ferns we have. It occurs most freely on mounds of humus in the 

 forest, often climbing for some distance up the trunks of trees. Small 

 plants often grow on the stems of tree-ferns. 



20. Nephrodium Rich. 



Eight species, all of which, except the Kermadec Island N. setigerum 

 Bak., occur in the county. 



N. Thelypteris Desv. var. squamulosum Schlect. is found in several 

 swampy places from the North Cape to Reef Point, rarely far from the sea. 



This is one of the seven species of ferns which are common to Europe 

 and the Southern Hemisphere. The others are Hymenophyllum Tun- 

 bridgense, H. unilatemle, Aspidium aculeatum, Gymnogramme leptophylla, 

 Ophioglossum vidgatum, and Botrychium lunaria. 



The var. squamulosum appears to be confined to New Zealand and 

 South Africa. 



N. decomposition R. Br. is not uncommon in damp woods in rich alluvial 

 soil. 



N. glabellum A. Cunn. occurs freely in damp shady forests. ' Botanists 

 are indebted to Mr. Kirk for clearing up the confusion which had arisen 

 regarding this and the preceding species/'* 



The main differences are that N. decomposition has a creeping rhizome, 

 the fronds being scattered along it, while A 7 , glabellum has a short tufted 

 rhizome, with the fronds much narrower at the base and darker in colour. 



N. velutinum Hook. f. is usually found in hilly forest, generally in rocky 

 ground. The dense velvety pubescence distinguishes it from allied plants. 



; 'The Ferns and Fern Allien of New Zealand," G. M. Thomson, p. 82. 



