20 THE FLORA OF THE NORTHERN TERRITORY. 



PANDANACEffi. 

 1. PANDANUS, Linn. 



Drupes connate in clusters, nearly flat on the apex. Male spikes sessile. — 



2. P. odoratissimus. 

 Drupes all free. — 1. P. aquaticus. 



1 . P. aquaticus, F. v. M. — Upper Victoria River, P. v. Mueller. 



2. P. odoratissimus, Linn. — Arnhem's Land and Islands of the Gulf of 

 Carpentaria, F. v. Mueller ; Port Darwin, Schultz (No. 613) ; Escape Cliffs, 

 Hulse ; King's Sound, Hughan. 



POTAMOGETONACEiB. 



Tribe L — Flowers hermaphrodite. Anthers short and broad, sessile at 

 the base of the scale-Kke perianth segments. Carpels 3 to 6, 1-seeded. — 



1. Potamogeton. 



Tribe 2. — Flowers hermaphrodite or unisexual. Perianth none or rudi- 

 mentary or in one sex only. Carpels 1 or 3 or rarely more, 1-seeded or rarely 

 several-seeded. Aquatic submerged plants, mostly marine or subsahne. — 



2. Cymodocea. 



1. POTAMOGETON, Linn. 1735. 



(Buccaferrea, Bubani, 1873. Groelandia, Fourr, 1869. Groenlandia, 

 J. Gay, 1854. Peltopsis, Rafin, 1819. Sprillus, J. Gay, 1854.) 

 Pond Weed. 



Section 1 . — Leaves all alternate and petiolate with floating laminae, or the 

 lo\^'er ones submerged. Stipules connate within the petiole. 



Floating leaves 1 to 2 in. long. Nutlets beaked. — 3. P. tricarinatus. 



Floating leaves to \ in. long. Nutlets distinctly beaked. — 2. P. tenui- 

 caulis. 



Section 2. — Leaves all submerged, sessile or nearly so, those under the 

 peduncles and branches opposite, the others alternate. Stipules connate within 

 the petiole, often very deciduous. — 1. P. crispus. 



1. P. crispus, Linn. — Albert River, F. v. Mueller. 



2. P. tenuicaulis, F. v. M. — Gulf of Carpentaria, F. v. Mueller. 



3. P. tricarinatus, F. v. M. and A. Benn. — Hugh River, Macdonnell 

 Ranges, G. F. Hill (No. 132), 4/5/1911. 



Pond Weed. — Liable to give trouble in ponds, etc. 



The National Herbarium Census also records P. natans Linn, from North 

 Australia. 



2. CYMODOCEA, Koen. 



1. C. ciliata, Ehrenb. — Whitsunday Islands, Kilner. 

 C. rotund ata Asch. and Sch. and C. isoetifolia Asch. and Sch. also recorded 

 in National Herbarium Census from North Australia. 



NAIADACE^. 



1. NAIAS, Linn. 



1. N. major, All. — Flinders River, F. v. Mueller. 



N. tenuifolia also recorded in National Herbarium Census from North 

 Australia. 



