1700 CXLVI. LEMNACEiE. 



exserted, anther 1 or 2-celled. Ovary 1 -celled, with 1 or more ovules. Style 

 short, with a slightly thickened stigma. Fruit a minute utricle. Seeds 1 or 

 more, with or without albumen. 



The Order, Is limited to two geneia ; the Renus represented in Queensland is widely 

 spread over the glohe in ponds or standing waters. 



1. LEMNA, Linn. 



(Eeferrinp' to the scale-like fronds.) 



Fronds emitting one or more root fibres from their under surface. Flowers 

 issuing from a fissure in the margin of the frond. Anthers with 2 distinct cells, 

 each opening in two valves, at the end of a distinct filament. Style short or more 

 or less lengthened. 



Geographical distribution that of the Order. 

 Eoot-fibres one to each frond. 



Fronds very thin, oblong or narrowed at one end, the young ones often 



projecting on each side at both ends. Ovules 1 I. L. trisulca. 



Fronds broadly ovate, rather thin, slightly convex underneath, the young 



ones soon detached from one side. Ovule 1 2. i. minor. 



Eoot-fibres several in a cluster under each frond. 

 Fronds thin, oval or oblong, rarely above 2 lines long 3. L. oligorrldza. 



1. Zi. trisulca (3-furrowed), Linn.; Her/elm. Lenin. 134, t. 5, 6; Benth. Fl. 

 Austi: vii. 162. Fronds oblong or lanceolate, often ^in. long and about half that 

 breadth, thin, narrow and minutely toothed at one end and ending in a little 

 stalk at the other, with 2 young ones usually growing from opposite sides and 

 remaining long adherent, and emitting a single root from underneath. Stamens 

 usually 2. Ovary with 1 ovule and a very short style. — R. Br. Prod. 345 ; Hook, 

 f. Fl. Tasm. ii. 88 ; F. v. M. Fragm. viii. 188 ; Griff. Sc. PI. Asiat. t. 262. 



Hab.: Darling Downs. Common ia the northern hemisphere. 



2. Ii, minor (smaller), Linn.; Ilegelm. L^emn. 142, t. 9, 10; Benth. Fl. 

 Austr. vii. 163. Fronds usually broadly ovate, about 2 lines long, rather thin, , 

 emitting a single root from the under surface, the young frond growing from one 

 side, becoming soon detached. Stamens usually 2. Ovary with a single ovule. 

 — R. Br. Prod. 345 ; Hook. f. Fl. Tasm. ii. 38 ; F. v. M. Fragm. viii. 188. 



Hab.: Bockbampton, O'Slianesy, Bowman ; Brisbane, Bailey. 

 The commonest species in most parts of the area of the genus. 



8. Ii. oligorrhiza (roots few), Eui-. ; Heijelm. T^emn. 147, t. 16 ; Benth. FL 

 Austr. vii. 163. Fronds thin, oval or oblong, resembling those of I., minor, but 

 usually rather larger though rarely much above 2 lines long, 3 or 5-nerved, and 

 emitting from the underside a cluster of several roots or fibres, usually 2 to 5 but 

 sometimes more. Fructification unknown. — /.. pleiorrhim and //. }iielanorrhi,~a, 

 F. v. M. ; Kurz in Seem. Journ. 1867, 115. 



Hab.: Common. 



The species appears to be spread over East India and the Malayan Archipelago. 



