864 NOTES ON NEW ZEALAND FERNS. 



constantly grow together (that is, dicarpa seems only to grow along 

 with circinndtti, though the latter is often found alone), and are so 

 mixed that I often think they must spring from the same rhizomes, 

 though I have never been able to extract a rhizome with both 

 kinds of frond upon it from the mud and moss of the swamps in 

 which they occm\ I find, too, that some masses of the swamp- 

 soil containing these ferns, which I was at some pains to bring 

 down from the mountains, and plant in a favourably wet place in 

 my garden, have for the last three years only produced circinnata 

 fronds, though they contained quite an equal number of diccuya 

 ones when I procured them. 



I may next note the characteristics of the caudices of our 

 arborescent ferns. Cyatliea medidlaris grows to an ultimate height 

 of from forty to a hundred feet or more, and the fronds, on 

 withering, break short off from the caudex, leaving a rhomboidal 

 scar on the latter, to show where each one grew. Thus the whole 

 outer surface of the caudex consists of these scars, except just at 

 the bottom, where there is often a small cone of fibrous matter, 

 which occasionally attains the dimensions of eighteen inches in 

 diameter at its base, and two feet or more in height. It consists 

 of apparent root-fibres growing longitudinally doAvnwards from the 

 caudex, but adhermg firmly together. It is caUed "Weki" by 

 the Maoris, who split it into slabs, and use it to line then' potato- 

 pits and storehouses, partly because it is almost imperishable and 

 imper\ious to moisture, and partly because rats and mice do not 

 gnaw through it as they will through wood. C. Cunninghami 

 seems never to exceed fifteen or twenty feet in height, and its 

 withered fronds, or then* rachises, remain hanging around the 

 caudex for many years, often in fact nearly concealing it. When 

 they di'op the separation seems efiected by a sort of healing 

 process, which has gradually diminished the diameter of the 

 actual base of the stijie, so that only a small scar remams on the 

 otherwise smooth surface of the caudex. There is also occasionally 

 a small cone of weki at the base of the caudex. C. dealhata attains 

 a height of from thirty to fifty feet, and its caudex is quite different. 

 The withered fi-onds are separated by their stipes breaking off at a 

 distance of about eight inches from the caudex, which is roughened 

 with them, and actually concealed by them (as they closely overlap 

 each other) for the greater portion of its length. Ultimately they 

 disappear, partly through perishing under atmospheric influence, 

 but mostly through bemg buried in weki, which on these ferns 

 not only forms cones often five to six feet high, by three feet in 

 diameter at the ground, but covers the whole caudex, so as to 

 make it often a foot or more in diameter. Hemitelia Smithii only 

 grows to a height of fi'om fifteen to twenty feet, rarely exceeduig 

 the former. Its withered fronds hang in a collar round the head 

 of the caudex, just below the crown, for several years, and then 

 either drop short off or leave so small a portion of stipe behind 

 them that it is immediately covered up in weki, which in these 

 ferns forms the whole outer surface of a caudex as thick as that of 

 C. dealbata, but seldom, if ever, a basal cone. Alsophila Colensoi 



