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libero; venule segmenti paucw pinnate disposite inconspicum. Sori singuli 
plerumque ad media segmenta, prope pinne costam dispositi, indusio persistente. 
Textura coriacea ; lamina superne fusca, inferne griseo-viridis. 
Hab. Arfak Mts., Koebré Mt., 7000-8000’, epiphytic in forest. Dee. 
5627. 
The lower pinnules are slightly deflexed, and the lowest pair are a trifle 
shorter than the pair above them. The plant differs in every respect from 
D. viscosa. 
POLYBOTRYA ARFAKENSIS Gepp, sp. nov. 
Stipes paleis linearibus brunneis + deciduis 0°5 cm. longis vestitus et earum 
cicatricibus muricatus, 15 cm. longus, atro-purpureus. rons circa 1 m. longa, 
40 cm. lata, bipinnata obovato-lanceolata ; rhachis atro-purpurea + paleacea muricata 
(velut stipes) ad apicem haud evoluta, superne breviter ferrugineo-tomentosa, inferne 
parum furfuracea, pinnas circa 9 alternas remotas dimorphas (inferiores 6 fertiles, 
superiores 3 steriles) gerens; pinne brevi-stipitate ad apicem abrupte (haud 
evolutz), steriles circa 30 cm. longer, 13 cm. late, lanceolate, fertiles circa 25 cm. 
long, 7°5 cm. late; rhachis pinne superne ferrugineo-tomentosa ; pinnule alterne 
circa 12-jugate stipitate; pinnule steriles 6°5 cm. longe, 1°2 cm. latex, oblongo- 
lanceolatz acuminate apice serrato, usque ad 4 pinnatifide, lobis (fere 20-jugatis) 
rotundatis crenulatis, venulis in lobis pinnate dispositis c. 3-jugatis; pinnule fertiles 
+ 3°5 cm. longe, 4-8 mm. late, lineares usque ad costam pinnatisectw, lobis parvis 
oblongis sessilibus propter soros copiosos omnino obtectis. Textwra subcoriacea. 
Lamina superne purpureo-brunnea, inferne pallidior glabra. 
Hab. Arfak Mts., 8.W. ridge, Angi lakes, 7000’, climbing in forest, 
clasping trunk to top. Dec. 5984. “Fronds 1 m. long, sterile like barren 
portion of fertile frond ; fertile frond distinct.” 
This fern is remarkable for its dimorphous fronds and pinne and for the 
arrested growth of its frond-apices. The material consists of one frond, 
the six lower pinne of which are fertile, and the three upper are sterile. 
The apex of the main rhachis has failed to attain its full development, as also 
have the apices of the secondary rhachises (pinnz both fertile and sterile). 
Hence, the proper apices are absent. Whether the apical growth has been 
temporarily interrupted or permanently arrested, and whether the arrest of 
growth is due to injury or is of normal occurrence in the life-history of the 
plant is uncertain. The lower pinne are shorter than the others. The 
sterile pinnules are inserted at intervals of about 2 em., the fertile at about 
15cm. The fertile pinnules recall those of Osmunda javaniva in shape, but 
not in arrangement. Dimorphism of frond and pinne occurs in the tropical 
American P. osmundacea. 
P. arfakensis climbs by means of its rhizome and puts out its fronds at 
right angles to the axis of the tree up which it climbs, 
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