Citation: L., Sp. Pl. 325 (1753).

Derivation: Latin name for a rush.

Synonymy: Not Applicable

Common name: Rushes.

Description:
Plants mostly growing near the water or in seasonally wet areas and the perennial species often with strong creeping rootstocks; cataphylls open (slit to the base); leaves glabrous.

Each flower with or without 2 small hyaline bracteoles at the base; small lanceolate scarious bracts at the base of the panicle branches, or the lowest (primary) bract longer than the particle and sometimes appearing as a continuation of the stem; stamens 3-6; ovary with 3 parietal placentas often meeting in the centre and dividing the ovary more or less perfectly into 3 cells.

Seeds small, numerous, on parietal placentas, with a membranous testa often loose and transparent at the end.

Distribution:  About 300 species, cosmopolitan.

Biology: No text

Taxonomic notes: This treatment owes a great deal to L. A. S. Johnson and K. L. Wilson (Royal Botanic Gardens and National Herbarium, Sydney) who revised my manuscript for the previous edition, making numerous improvements.

Key to Species:

1. Leaves 0 or cylindrical (non-septate) and resembling the stems; primary bract apparently continuous with the stem, inflorescence thus appearing lateral
2. Leaf-blades developed
3. Perianth-segments half as long as the capsule; inflorescence compact	J. acutus 1.
3. Perianth-segments as long as the capsule; inflorescence expanded	J. kraussii 15.
2. Leaf-blades reduced to basal sheaths
4. Stems with continuous pith
5. Upper portion of stems, inflorescence branches and outside of perianth scabridulous	J. radula 21.
5. Stems, inflorescence branches and outside of perianth not scabridulous
6. Perianth longer than the capsule; cataphylls not shining; stamens 3	J. effusus 11.
6. Perianth shorter than the capsule; cataphylls more or less shining; stamens 3-6
7. Cataphylls a dark reddish-brown, tight; stem striations 20-45; flowers mostly widely separated along the inflorescence branches	J. pauciflorus 17.
7. Cataphylls golden to chestnut-brown at the base, often more or less loose; stem striations 3:5-100; flowers not widely separated
8. Perianth 1.6-2.5 mm long; capsule 1.8-2.7 mm long; stamens usually 3	J. continuus 10.
8. Perianth 2.6-3.5 mm long; capsule 2.8-3.5 mm long; stamens 6	J. pallidus 16.
4. Stems with an interrupted pith
9. Capsule longer than the perianth
10. Stem striations more than 75; cataphylls golden within, broad and loose; stems green	J. procerus 20.
10. Stem striations 20-90; cataphylls opalescent and mostly pale within; stems green to glaucous
11. Perianth 1.3-2.2 mm long; cataphylls a dark reddish-brown to black below; stamens 3 or 4
12. Capsule 2-2.5 mm long; stem striations 10-12 per mm; pith very open, consisting mainly of air-spaces	J. amabilis 2.
12. Capsule 1.5-2 mm long; stem striations 6-9 per mm; pith ladder-like, air-spaces and partitions more or less equal	J. usitatus 25.
11. Perianth 2-4.1 mm long; cataphylls pale- to chestnut- brown below (or if reddish-brown then perianth more than 3 mm long); stamens 3-6
13. Stem striations 20-35; longest cataphyll 4-10 cm	J. subsecundus 24.
13. Stem striations 40-90; longest cataphyll 13-30 cm	J. aridicola 3.
9. Capsule shorter than the perianth
14. Capsule 1.7-2.3 mm long; longest cataphyll 1:5-30 cm	J. sarophorus 22.
14. Capsule 2.3-3.5 mm long; longest cataphyll 4-19 cm
15. Stem striations 20-35; cataphylls often pale, longest 4-10 cm	J. subsecundus 24.
15. Stem striations 35-100; cataphylls chestnut- to dark- brown at the base, longest 6-19 cm
16. Perianth 2-3 mm long; stem striations 3:5-60, distinct	J. australis 5.
16. Perianth 3-3.2 mm long; stem striations 50-120, very crowded	J. flavidus 12.
1. Leaves flat or cylindrical and septate; inflorescence usually terminal
17. Leaves hollow, cylindrical or laterally compressed, transversely septate
18. Stems c. 0.5 mm diam., terete, septa usually not obvious	J. bulbosus 7.
18. Stems 1-5 mm diam., terete or compressed, septa usually obvious
19. Perianth 2-2.5 mm long	J. subnodulosus 23.
19. Perianth 2.5-4 mm long
20. Leaves terete (when fresh) or compressed, with transverse septa only; stamens 6
21. Flowers 4-10 per final cluster, dark-coloured; plant obviously rhizomatous	J. articulatus 4.
21. Flowers usually 10-20 per final cluster, pale-coloured; plant shortly rhizomatous	J. holoschoenus 13.
20. Leaves compressed, with longitudinal and incomplete transverse septa; stamens 3	J. prismatocarpus 19.
17. Leaves solid, dorsi-ventrally flattened, not septate
22. Small annuals
23. Stem-leaves absent; flowers ebracteolate, in a terminal cluster	J. capitatus 9.
23. Stemqeaves present; flowers bracteolate, solitary or in small clusters	J. bufonius 6.
22. Perennials
24. Leaves flat; the leaf-base not auriculate; flowers ebracteolate
25. Stamens 3	J. planifolius 18.
25. Stamens 6	J. caespiticius 8.
24. Leaves very narrow; the leaf-base auriculate; flowers bracteolate	J. homalocaulis 14.

Author: Not yet available