108 335 
c. 5 mm. longum, inferius obcordatum emarginatum, c. 10 mm. 
latum, c. 8 mm. longum; palatum valde elevatum (galeiforme), 
laeve; calcar elegans, angustum, 6—7 mm. longum, leviter cur- 
vatum; capsula ovoida; semina subglobosa vel globoso-ovoidea, 
scrobiculata, c. 0,30 mm. longa, cellulae testae leviter denseque 
striatae. 
Related to U. bifida and U. Wallichiana Wight; it has about the 
same shape of the seed-testa and of the bladders as U. bifida (see Fig. 2), 
also the prominence of the innerside of the bladder-stalks mentioned by 
Goebel (Ann. Jard. Buitenzorg, IX, 73, fig. 54) occurs in our species, 
the leaves, stolons and rhizoids are very like those of U. bifida, but the 
leaves are much more numerous and large, further 3- (rarely 5-) nerved 
(not uninerved). It is also easily distinguable by the long flower-stalks, 
the large underlip of the corolla and the narrow spur. 
H. N. Ridley (Journ. of Botany, vol. 33, 1895, p. 11) describes 
an U. involvens from the Malay Peninsula (Kedah), which comes near 
to our species. It differs in the narrower leaves, the much higher stem 
(“‘circiter pedalis”), the shape and largeness of the calyx lobes and the 
straight spur, but the descriplion is very incomplete, e. g. the bladders 
and the fruit are not mentioned. 
Very common in river-beds in the jungle all over Koh Chang. Some 
specimens were submerse, other terrestrial. Flowers yellow. Collected 
(with flowers) at Klong Munsé (Jan. 5th & 18th (No. 61), Klong Son 
(Feb. 28th, No. 679b), and Klong’ Prao (March 8th, No. 704 a). 
