T. Kirk. — On the Discovery of Arnphibtforuus in New Zealand. 375 



pedicellate 5-7 flowered, faintly pubescent ; outer glumes unequal, one- 

 third the length of the spikelets ; flowering glume more than twice as long 

 as the outer glume, 5-nerved, bifid, awn dorsal springing from near the base 

 of the glume, free at its apex, scabrid, not twisted, palea equalling the 

 flowering glume, with 2 stout ciliated nerves, truncate, the apex and upper 

 margins ciliated ; caryopsis free. 



Hob. North Island : in shallow waters, margins of the Waihi Lake and 

 Creek. 



Stamens 3, lodicules narrow, acute ; stigmas 2, minute, ovary loosely 

 invested by the palea. Flowering glume with a few short hairs at the base. 

 Pedicels varying from J"-l^" in length : occasionally two or more pedicels 

 spring from the same point, but in cases of this kind one pedicel is greatly 

 abbreviated. 



Our plant is readily distinguished from all other indigenous grasses by 

 its fluitant habit ; although in very shallow water it is suberect, yet as a 

 general rule little more than the panicle is elevated above the water. 

 Owing to the rhachis of the spikelet being articulated below each flower, the 

 glumes fall away almost immediately after the extrusion of the panicle from 

 the sheath, leaving only the naked pedicels, so that there is but little to 

 attract attention to the plant, which may easily be passed unnoticed. 



Amphibromus jiuitans is usually if not invariably cleistogamous, fertiliza- 

 tion being effected before the panicle is extruded : in fact extrusion is often 

 delayed until the grain is nearly matured. I suspect that the stamens are 

 not always developed in the uppermost flowers of each spikelet, but the 

 flowers must be collected in an earlier state, before this point can be posi- 

 tively determined. 



Our plant differs from the Australian species A. neesii, Steudel, in the 

 procumbent habit, shorter leaves, smaller panicle, and straight awn. A. 

 neesii is found in all the Australian Colonies except Queensland, and attains 

 its greatest luxuriance in moist situations. 



EXPLANATION OF PLATE XXVIII. 



1. Amphibromus Jiuitans, natural size. 



2. Flowering glume, lateral view. 



3. Palea, front view. 



4. Caryopsis, all magnified. 



