THE FLORA OF THE NOBTHEEN TERRITORY. 53 



Spikelets solitary or clustered in an irregularly branched inflorescence, 

 when 2- flowered the lowest sterile, and often unisexual. Stamens 3 to 6. 

 Nut crowned by the ovoid or oblong base of the style. — 14. Caustis. 



Spikelets in a small terminal head. Stamens or staminodia 6. — 10. 

 ArthrostyUs. 



Tribe III. — Flowers strictly unisexual, in unisexual or androgynous 

 spikelets. No utricle enclosing the females. Ovary and nut seated on a disk.^ 

 15. Scleria. 



1. LIPOCARPHA, R. Br. 



1. L. microcephala, Kunth. — Cullen Creek, Spencer and GUruth, Julv- 

 August, 1911. 



Recorded. Arnhem S. Bay, R. Brown ; between Norman and Gilbert 

 Rivers, Gulhver ; Port Darwin, Schultz (No. 78). 



2. CYPERUS, Linn. 1735. 



(Ano8por^(m, Nees, 1834; Atomostylis, Steud., 1850; Bobartia, Linn, 

 1747 ; Borabora, Steud., 1855 ; Hydroschoenus, Zoll. and Mor., 1846 ; Opetiola, 

 Oaertn., 1788 ; Papyrus, Willd., 1812-13 ; Pterocyperus, Opiz., 1852 ; Soro- 

 stachys, Stevd., 1850 ; Torreya, Eafin., 1819 ; Torulinium, Desv., 1825 ; 

 TrentepoMia, Bolck, 1858). 



Section I. — Spikelets flat with na^dcular keeled glumes. Styles usually 

 2-cleft. Nut more or less flattened, with one edge next the rachis. 



Nut oblong, not exceeding half the length of the glume. Spikelets narrow, 

 very numerous, in a dense sessile compound cluster, rarely with 2 or 3 elongated 

 umbel-rays. — 19. C. polystachyus. 



Nut broad, almost as long as the glume. Tall perennial. Spikelets 

 loosely spicate and distichous along the rays of a large compound umbel. — 

 12. C. flavicomus. 



Section II. — Spikelets flattened but usually thick. Style 2-cleft or rarely 

 3-cleft. Nut ovate or broad, with a flat or concave face next the axis, the back 

 convex or with a raised central angle. — 21. C. pygmaeus. 



Section III. — Spikelets flat, the rachis not winged or rarely with an ex- 

 ceedingly narrow border. Style 3-cleft. Nut equally triquetrous. 



Spikelets numerous, in a single small dense globular head, with an in- 

 volucre of long slender bracts. — 20. C. pulchellus. 



Spikelets numerous, clustered or capitate, the clusters or heads solitary or 

 in an umbel of few rays. Glumes with a prominent straight or recurved point. 

 Small annuals (Squarrosi). — 25. C. squarrosus. 



Spikelets dark-coloured, clustered or capitate in an umbel of few rays or the 

 clusters rarely, solitary. Nuts broad, as long as the glume (Nigricantes). — 

 8. C. difformis. 



Spikelets pale or brown, clustered, capitate or sohtary on the rays of a 

 umbel. Nuts broad, not above half the glume. (Compressi). 



Involucral bracts few, unequal, one or two longer than the inflores- 

 cence or aU short. 



Umbel-rays few. Stems weak. Spikelets oblong. Glumes 

 acutely keeled, with one nerve in the middle of each side. — 

 28. C. trinervis. 

 Umbel-rays numerous. — 16. C. Haspan. 

 Involucral bracts about 6, nearly equal rigid, erect or spreading. 

 Umbel many-rayed or reduced to a dense cluster. Stem leafless. 

 — 29. C. vaginatus. 



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