THE FLOBA OF THE NORTHERN TERRITORY. 57 



Spikelets clustered, above 2 lines long, oblong or narrow. Style branches 

 3. — 1. S. articulatus. 



Section TI. Euscirpus. — Hypogynous bristles 3 to 8. Plants mostly 

 tall and stout. 



Spikelets in sessile lateral clusters. — 2. S. debilis. 



Spikelets in terminal or nearly terminal simple or compound irregular 

 umbel or cluster. — 4. S. litoralis. 



1. S. articulatus, Linn. — Abrahams' Lagoon, Spencer and Gilruth, 

 July- August, 1911. 



Recorded. Mouth of Victoria River, F. v. Mueller. 



2. S. debilis, Pursh. — Upper Victoria River and Sturt's Creek, F. v. 

 Mueller. 



3. S. Jmmillimus, Benth. — South Alligator River, Arnhem Land, F. v. 

 Mueller. 



4. S. litoralis, Schrad. — Culf of Carpentaria, R. Brown, F. v. Mueller ; 

 Victoria River, F. v. Mueller ; Roper River, GulUver. 



5. S. squarrosus, Linn. — In the interior, lat. 70 degrees, 50 minutes, 

 M'Douall Stuart's Expedition. 



5. HBLEOCHARLS, R. Br. 



Spike-Rush. 



Section I. Limnocharis. — Spikelets cylindrical. Glumes obtuse, not at 

 all or very obscurely keeled, rather rigid, with a hyaline border. Persistent 

 base of the style forming a conical usually flat beak to the nut. 



Stems terete, appearing articulate from the transverse septa dividing the 

 internal pith. — 5. H. sphacelata. 



Stems continuous, obtusely triquetrous or terete. — 6. H. variegata. 



Section II. Scirpidium. — Spikelet cylindrical or tapering upwards, 

 usually smaller than in Limnocharis. Glumes with a distinct green centre or 

 prominent keel. Per,sistent base of the style shortly conical. 



3 to 7 bristles arising below the base of each ovary. — 1 . H. acuta. 



No bristles around the ovary. — 2. H. atricha. 



Section III. Heleogenus. — Spikelets ovoid ; conical or small and few- 

 flowered. Glumes keeled. Persistent base of the style short and depressed. 

 Leaf -sheath oblique at the orifice, often soarious. 



Spike dense, many- flowered, pale-coloured. Stems mostly above 6 in. 

 high. Glumes broad, with a green centre. 4. H. capitata. 



Spike loose, dark-coloured, the glumes not very numerous, prominently 

 keeled. Stems under 3 in. — 2. H. atropurpurea. 



1. H. acuta, B. Br.— Lake Woods, G. F. Hill (No. 489), 2/8/1911. 



2. H. atricha, R. Br. — Between Norman and Gilbert Rivers, Gulliver. 



3. H. atropurpurea, Kunfh. — Victoria River, F. v. Mueller. 



4. H. capitata, R. Br. — Gulf of Carpentaria, R. Brown ; Sea Range and 

 Victoria River, F. v. Mueller. 



5. H. sphacelata, R. Br. — Gulf of Carpentaria, R. Brown ; Arnhem Land, 

 F. V. Mueller. 



6. H. variegata, Kunth (H. compacta, R. Br.). — Arnhem N. Bay, R. 

 Brown ; Lower Victoria River, F. v. Mueller. 



H. spiralis, R. Br. ; recorded in National Herbarium Census from North 

 Australia. 



