a ee 
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sometimes confluent at the apex. Filaments 1 mm. long and +°5 mm. 
thick, with the connective produced at the apex. The ovary is flattened in 
one plane, 4 mm. by 2°5 mm., 8-10-angled according to the number of 
stamens. The thick circular style is 1 mm. high. 
IDENBURGIA ARFAKENSIS Gibbs, sp. nov. 
Arbuscula, glaberrima, ramuli divaricati, cortice striato cinerascente preediti. 
Folia opposita, petiolata, ovato-lanceolata, tenuiter caudato-acuminata, basi »ttenuata, 
glanduloso-serrata, membranacea, nervis subtus prominentibus 5-6, rete venulorum 
eonspicuo. acemus terminalis, foliis duplo brevior. Tepala 4, petaloidea, decus- 
sato-imbricata, rotundata, apice obtusa. Stamina 6, antherarum connectivo haud 
apiculato. 
Hab. Arfak Mts., Koebré ridge, on open summit, 9000’. Fl. Dec. 
6003. 
Leaves 11 by 3:3 em. (ineluding petiole 6 mm. long and acumen 1°5 cm. 
by 1 mm.), dull brown in colour above with veins barely visible, lighter 
beneath with dark brown veins, the midrib being produced into the extreme 
apex of the acumen. Racemes 2 em. long; pedicels 6 mm. long, the upper 
ones shorter. Flowers 5 mm. long in bud. Stamens 4 mm. long and 
1:1 mm. broad, with the rim of the anthers +5 mm. broad and filaments red- 
brown, when dry. Ovary 3mm. long. Stigma just over 1 mm. high. 
The Trimeniaceze comprise the two anomalous genera Trimenia and 
Piptocalyx (1 cannot accept Xymalos as showing any affinity with either 
genus), which have so far been included in Monimiacez, under Tribe II. 
Trimeniese, though showing little relation to such a systematic position ; 
indeed Perkins and Gilg (Das Pflanzenreich, iv. 101. 11), the monographers 
of that order, consider that with a better knowledge of the two genera they 
would probably show themselves as not related to the Monimiacee. The 
correctness of this point of view is borne out by the discovery of the new 
genus Idenburgia, including two species very closely related to both the 
above genera, but with a synearpous bilocular ovary. 
A very interesting sequence in development is shown in the floral 
structure of the three genera. In Jdenburgia the flowers are hermaphrodite, 
whereas both Trimenia (T. weinmannicefolia Seem. from Fiji, for many years 
the sole representative of the genus) and Piptocalyx were supposed to be 
diccious ; 7. papuana Ridley, however, recently discovered in Dutch 8.W- 
New Guinea by Kloss, like J. arfakensis, is hermaphrodite, The monotypic 
Piptocalyzx is dicecious. 
The many spiraliy-arranged perianth segments of Trimenia, graduating 
from scales to petaloid tepals, are reduced in Piptocalyx to six biseriate 
petaloid tepals ; whereas in Jdenburgia we get four large biseriate petaloid 
tepals—in each case, however, equally caducous, falling before anthesis, 
exposing the stamens before these mature. The structure of the stamens 
M 
