Wilson and Johnson, Juncus (Juncaceae) in Malesia 
377 
J. decipiens subsp. medianus L.A.S. Johnson et K.L. Wilson, subsp. nov. 
Inter ambas subspecies ceteras intermedius ut videtur; a subspecie typica tepalis 
longioribus, cataphyllis rufioribus differt; a subspecie sundaica tepalis brevioribus, 
cataphyllis distaliter stramineis non nisi basi rufis, differt. 
Type: Papua New Guinea: J. Leahey's mill site, Goroka Subdistrict, 7,300 ft [2200 m], 
A.G. Floyd and J.S. Womersley 6297, 18 Nov 1954; holo NSW; iso CANB, K, L, LAE. 
Culms 25-120 cm long, l.l-2.5(-3.0) mm diam.; striations 23-47. Cataphylls 3-19 cm 
long, abaxially straw-coloured or pale red-brown for Vi-Vi of its length grading to red- 
brown or dark red-brown towards base. Inflorescence 2-9 cm long; lowest involucral 
bract 9-35 cm long. Tepals acute to acuminate, straw-coloured, often with darker 
yellow-brown or red-brown band on each side of midrib, with broad hyaline margins; 
outer tepals 2.1-2.7(-3.1) mm long. Anthers 0.4-0.8 mm long, shorter than to exceeding 
filament length. Capsule slightly shorter than to slightly exceeding outer tepals, 
ellipsoid to oblong or ovoid, dark golden brown to red-brown, umbonate. Seeds 
0.4-0.5 mm long. 
Illustrations: Fig. 2c, d; also Backer (1951: fig. 1); Kao and De Vol (1978) (as J. effusus 
var. decipiens)-, Van Steenis (1972: pi. 24-3). 
Distribution: In Malesia found at higher altitudes (1,200-3,000 m) on the islands of 
New Guinea (West Papua and Papua New Guinea), Philippines (Luzon and 
Mindanao), Borneo (only Mt Kinabalu so far as known), Java (West and Central); also 
in Taiwan. 
Notes: The epithet is taken from the Latin medius (neo-Latin medianus), the middle 
[adjective]; referring to the apparently intermediate position of this taxon 
morphologically between the type subspecies and subsp. sundaicus. For example, the 
tepals of subsp. medianus are intermediate in length between those of the other 
subspecies, although the hyaline to membranous tepal margins differ in being usually 
slightly broader (to 0.2 mm wide) than in either other subspecies. The cataphylls are 
also intermediate between the other subspecies in the extent of red coloration (the 
upper V4-V2 is straw-coloured in this subspecies). 
Selected collections examined: JAVA: s. loc., P. Goeritig 344, 1851 (P); s. loc., T. Horsfield 1070, - (BM); 
Dieng, F. Junghuhn 602, - (L); Preanger, Pangentjongan, S. Koorders 26505, 26 Jan 1897 (K, L); Priangan, 
Tegal Kirinjoeh, Papandajan, 2060 m, L. van der Pijl 567, 17 May 1936 (K); Preanger River, Afd. 
Tjikakapa v.d. Gouv. Kina Ond., 2000 m alt., D. van Slootcn 751, 3 Jan 1923 (K, L ex BO); Preanger, 
boven Bergtuin Tjibodas, Rawa Gajongjong, 1700 m, C. van Steenis 12331, 9-16 Nov 1940 (L). 
NEW GUINEA: West Papua: 9 km NE of Lake Habbema, 2800 m, L. Brass 10745, Oct 1938 (BRI, 
K, L); Bele River 18 km NE of Lake Habbema, 2200 m, L. Brass 11473, Nov 1938 (BRI, K, L); 
Saruwaged-Gebirge, 2400-3000 m, C. Keysser s.n. (BM); Wamena, Baliem River, 1800 m, 
A. Kostermans 813, 30 Aug 1966 (L ex BO); N of Mt Trikora, 3040 m, Baliem-Wamena river valley 
to the east, J.-F. Mangen 734, 25 Aug 1983 (L); Vogelkop Peninsula, Arfak Mountains, Anggi Gigi 
Lake, Soererei village, 1920 m, H. Sleumer and W. Vink BW 4358, 21 Jan 1962 (K, L); Wamena, 1701 
m, Ir. Soehoed Sosrodiliardjo 58, 6 Apr 1973 (L ex BO); Arupa, Wissel Lake region, C. Versteegh BW 
3020, 22 Mar 1955 (CANB, L, LAE (n.v.)). 
Papua New Guinea: Lake Onim, Subdistrict Ialibu, 2300 m, M. Andrew LAE 57133, Dec 1972 
(L, LAE (n.v.), NSW); Murray Pass, Wharton Range, Central Division, NG, L. Brass 4699, June-Sep 
1933 (BRI); above Aijura, B. Conn and Akakauaro 404, 24 July 1977 (L); Lake Myola No. 1, Subdistrict 
Kokoda, J. Croft et at. LAE 61941, July 1974 (K, L, LAE (n.v.), NSW); Mt Kenive (Nisbet), Subd. 
Kokoda, J. Croft LAE 65172, Aug 1974 (K, L, LAE (n.v.), NSW); Chimbu district, ridges c. 10 km SSE 
of Kundiawa, c.1900 m, P. Heyligers 1868 and J. Saunders, 16 Apr 1971 (CANB); Mannasat, Cromwell 
Mountains, Huon Peninsula, R. Hoogland 9445, July 1964 (CANB, L, LAE (n.v.), US); 
Momanemambuno, Mt Wilhelm, 2650 m, G. Hope ANU 10638, 1970 (CANB); Goroka subdistrict, 
10 km SE of Mt Kerigomna, 2500 m, K. Paijmans 1293, 16 Apr 1971 (CANB); western grasslands of 
