214 

 SYMBIOSIS IN GUNNERA MANICATA. 



In the April number of the Journal, Mr. Nash called attention 

 to a specimen of Gunncra manicata which was in full bloom at 

 the conservatories. Since then several other specimens of the 

 same species have blossomed at the Garden. Figure 31 is a re- 

 production of a photograph of two of the plants in house No. 13 

 of the conservatories. 



Libon is said to have disc 

 Lages of Santa Catharina, ] 

 and first cultivated in Linden's garden, but there is no record 

 that it ever flowered there. In fact its flowering seems to be a 

 rare occurrence, for Schwacke, writing in 1890, made the state- 

 ment that, " Except Fritz Miiller, no one has seen the flower." 

 It has also been found in the highlands of Santa Catharina, and on 

 the Sierra do Oratorio, at from 700-1,200 meters above sea level. 



The fifteen different species of the genus differ so greatly from 

 one another, both in habit and structure, that the genus is re- 

 garded as rather ancient. On account of these differences, also, 

 and because of the departure of them all from the dicotyledon 

 type, their classification has been difficult. The group was first 

 separated as a genus by Linnaeus, in 1767. By Jussieu and 

 Endlicher it was assigned to the Urticaceae, and by de Candolle, 

 Eichler, J. D. Hooker, and by Bentham and Hooker to the 

 Haloragidaceae. Baillon placed them with the Onagrariaceae, 

 and Lindley with the Araliaceae. 



According to Reinke(Morph.Abhand., Leipzig, 1873, p. 113), 

 the geographical center of dispersal of the genus is Van Diemens- 

 land and New Zealand, for the species of simplest structure, the 

 most primitive forms, occur there. 



The fibro-vascular bundles of the stem form a rather complex 

 network, thus varying widely from the dicotyl type, and the 

 internodes fail to elongate, making the stem short and partly 

 subterranean. The roots are said to possess no cambium, and 



from the dicotyledonous type in the direction of the monocoty- 

 ledons and ferns, and from that standpoint the plant would be 

 assigned to one of the lower groups of the plant kingdom. 



