41 



worked over the two areas, succinctly summarizes the whole relation of 

 both floras. 



This Malay-Papuan influence is the determining factor extending to the 

 South Sea Islands, while the Moluccas show Malay with Philippine ground- 

 types and a strong Papuan influence (23, i. 14, xx), and Schlechter describes 

 New Guinea as the centre of distribution of an endemic Orchid flora (" Aus- 

 gangscentrum einer eigener Orchideenflora ") (23, i. 14, xx) as evidenced 

 by Corysantltes, supposed to be Australian, but now truly Papuan, 13 species 

 being known from N.E. New Guinea alone. The presence of this genus in 

 Australia, New Caledonia, Samoa, Java, Philippines, and the Himalayas 

 suggests radiation from a Papuan centre of development (23, 14, xxiii). 



This overwhelming Papuan influence is amply demonstrated in many 

 other families, which not only show an actual numerical predominance in 

 species, but also a greater range of specific differentiation than is known 

 from elsewhere : for example, Libocedrus (4), Drimys (19), Myrtus (6) ; of 

 Pandanus and Freycinetia, I have never seen such a wide range in form ; 

 while in Rhododendron, Vaccinium, Styplielia, the numerical predominance 

 along with the great morphological range of form is unsurpassed in any 

 other region, except perhaps, in the case of the first, Central China. 



Further interesting proof of the soundness of this point of view is afforded 

 by comparison of the Australian and New Guinea representatives of the 

 same genera, the Papuan forms showing decidedly the oldest types. 



In the present collection perhaps Trimenia is the most striking case in 

 point. T. weinmannicefolia Seem., described in 1852 from Fiji, a dioecious 

 plant, remained the type of a supposed monotypic Polynesian genus, closely 

 allied to Piptocalyx Moorei, also dicecious, ranking as a monotypic Australian 

 one, till Ridley described T. papuana from Mt. Carstensz in 1916. T. arfak- 

 ensis is included in the present paper. 



Two species of Trimenia are now known from New Guinea, both 

 hermaphrodite, while two new species in a closely allied new genus, Iden- 

 burgia, show a syncarpous bilocular ovary, proving not only that the dioecious 

 habit of the two isolated outliers of this order is probably derived, but also 

 that the systematic position of Trimenia and Piptocalyx in the apocarpous 

 Monimiacese is untenable, necessitating the new order Trimeniacese. 



An equally convincing example is that of Pullea, a genus established by 

 Schlechter in Saxifragacese to include two plants with inferior ovary from 

 N.E. and N.W. New Guinea respectively, to which P. papuana is now 

 added, with a N. Queensland species, P. Stutzeri = CaUicoma Stutzeri 

 F. Muell., first distributed as Stutzeria by him, but afterwards included in 

 Callicoma. Pullea, therefore, now includes three distinct Papuan species 

 and one N. Australian, but, had the latter plant first been accorded proper 

 generic position, the former would have been cited as evidence of a wave of 

 Australian immigration into New Guinea. 



