Wilson and Johnson, Juncus (Juncaceae) in Malesia 
361 
inferred from the presence of old anthers adhering to the old stigmas near the apex of 
the capsule, the anthers having stuck to the moist papillate stigmas within the closed 
flower then having been ripped off the filaments by the enlargement of the ovary into 
the capsule — seen, for example, in J. capillaceus (pers. obs.) and noted in J, bufonius by 
Arber (1925: 187). 
The genus Juncus in Malesia 
Previous treatment 
Backer (1951) recognised four Juncus species in Malesia: J. bufonius L., J. effusus L., J. inflexus 
L. and /. prismatocarpus R. Br. 
As he noted, J. bufonius is probably an adventive species in that region. It is known 
only from a few disturbed localities on Mt Kinabalu (Borneo) and Mt Santo Tomas 
(Luzon). 
He did not comment on the status of the occurrence of /. mflexus in eastern Java, but 
that is probably also an introduction, since the species has its main native distribution 
in Europe, northern Africa, southwestern and central Asia (it is sporadically adventive 
in Australia and New Zealand). He regarded some collections from eastern Java 
(Tengger and Jang Plateau, 2100-2300 m alt. (Backer 1924)) with continuous pith but 
otherwise like typical J. inflexus as possibly representing the hybrid /. effusus x J. inflexus, 
but with doubt since they produced abundant fruit (Backer and Backhuizen f. 1968). 
/. effusus is a similarly widespread species in Europe, Western Asia and North 
America, and is also introduced in other parts of the world such as Australia and New 
Zealand. What Backer regarded as J. effusus in Malesia is here separated as J. decipiens 
(Buchenau) Nakai, a species native to continental Asia and Malesia. 
Confusion has surrounded the limits of /. prismatocarpus, with a wide range of names 
treated as synonyms or as infraspecific taxa in Asia and Malesia, including at times 
both unitubulose and pluritubulose taxa, for example in Buchenau (1890, 1906) and 
Van Royen (1979). We regard J. prismatocarpus as a pluritubulose-leaved species 
restricted to Australia and New Zealand. The Malesian material that Backer put under 
that name is referable partly to ]. leschenaultii J. Gay ex Laharpe (with pluritubulose 
leaves) and partly to /. wallichianus Laharpe (with unitubulose leaves). Both species are 
also in continental Asia. Given the confusion about the limits of J. prismatocarpus, a 
separate discussion of this and morphologically similar species in Malesia and 
continental Asia follows this Malesian treatment. 
More recently, Veldkamp (1977) described a new species from Papua New Guinea, 
J. nupela, and recorded the occurrence of J. bufonius on Mt Kinabalu (Veldkamp 1982). 
Tire only known collection of ]. sandzoithii from Papua New Guinea was made in 1974 
by J. Croft. Wilson (1986) mentioned the occurrence of the species in that country but 
without giving any details since the collection was from a non-alpine locality and 
therefore not the subject of the paper. 
Key to species found in Malesia 
Note. The non-Malesian /. prismatocarpus is included in the key for ease of comparison. 
This key is designed to be used with fertile, preferably fruiting, specimens. It is 
difficult to identify immature specimens of this genus when parts have not reached 
their maximum size. When bracteoles are present under a flower, the number is 
