|
Cyperaceae
Alternative names: Not Applicable
Description:
Usually perennial grass- or rush-like herbs ("sedges"); leaves often 3-ranked, with closed basal sheaths and usually linear blades, with or without a ligule; stems solid or hollow, often 3-angled.
Inflorescence a panicle, head or spike or spikelet solitary, often with 1-several leafy bracts at the base; flowers small, bisexual or unisexual, naked or with a perianth of scales or bristles, in the axil of scale-like bracts (glumes) comprising spikelets; stamens usually 1-3, rarely 4 or 6; anthers basifixed, 2-celled; ovary superior, 1-celled, with 1 erect anatropous ovule; style divided into 2 or 3 stigmatic branches.
Fruit an indehiscent dry nut (achene), flattened when the style is 2-branched, trigonous when it is 3-branched; seed erect, albuminous.
|
|
Distribution:
|
Cosmopolitan; about 4,000 species in 90 genera; about 650 species and 47 genera in Australia. (K. Wilson in Morley & Toelken (1983) Flowering plants in Australia 364-368; K. Wilson (1981) Telopea 2:153-172.)
|
|
|
Biology:
No text
Taxonomic notes:
Much assistance with this treatment has been given by Mrs K. L. Wilson of the National Herbarium of N.S.W.
Key to Genera:
|
1. All flowers in each spikelet or spike unisexual; glumes spirally imbricate round the rhachilla |
|
|
|
2. Nut enclosed in a utricle; leaves grass-like |
|
CAREX 4. |
|
2. Nut not enclosed in a utricle; leaves cylindrical |
|
CHORIZANDRA 6. |
|
1. All flowers in each spikelet bisexual or sometimes the uppermost or lowermost male; nut never enclosed in a utricle |
|
|
|
3. Glumes distichous, imbricate in 2 opposite rows (except Cyperus hamulosus which is included in the key to the species of Isolepis) |
|
|
|
4. Style not thickened at the base |
|
|
|
CYPERUS 8. |
|
|
|
6. Spikelets several-flowered; hypogynous bristles absent; rhachilla straight or slightly flexuose |
|
CYPERUS 8. |
|
6. Spikelets usually l-3-flowered; hypogynous bristles some-times present; rhachilla usually prominently zig-zag and more or less curved over the nut |
|
|
|
7. Spikelets solitary or capitate or paniculate |
|
SCHOENUS 17. |
|
7. Spikelets 2 or 3 in a short spike |
|
TRICOSTULARIA 19. |
|
4. Style thickened and hispid in the lower part, persistent as a more or less distinct beak on the nut |
|
|
|
8. Coarse plant with long leaves and a dense head of spikelets surrounded by short bracts |
|
GYMNOSCHOENUS 12. |
|
8. Slender almost leafless plants with few racemose or paniculate spikelets and setaceous bracts |
|
TETRARIA 18. |
|
3. Glumes spirally imbricate all round the rhachilla |
|
|
|
9. Spikelets maturing more than 3 fruits |
|
|
|
10. Style slender, not thickened towards the base |
|
|
|
11. Hypogynous bristles or scales 0 |
|
ISOLEPIS 13. |
|
11. Hypogynous bristles or scales 2-6 |
|
|
|
12. Hypogynous bristles or scales 3-6, not hyaline |
|
|
|
13. Involucral bracts leafy, usually several; culms noded |
|
BOLBOSCHOENUS 2. |
|
13. Involucral bracts culm-like, usually 1 rarely 2; culms usually nodeless |
|
SCHOENOPLECTUS 16. |
|
12. Hypogynous scales 2, flat and hyaline, enclosing the nut |
|
LIPOCARPHA 15. |
|
10. Style thickened at the base |
|
|
|
14. Style articulate on the ovary and deciduous as a whole from the nut |
|
FIMBRISTYLIS 10. |
|
14. Style not articulate, the base remaining attached to the ripe nut |
|
|
|
15. Plants leafy at the base; spikelets more than one to each stem |
|
BULBOSTYLIS 3. |
|
15. Plants leafless; spikelet one to each stem |
|
ELEOCHARIS 9. |
|
9. Spikelets maturing 1 or rarely 2 fruits each |
|
|
|
16. Hypogynous scales or bristles present |
|
|
|
17. Scales becoming broad, thick, and spongy under the nut; style thickened at the base; leaves all basal and equitant |
|
LEPIDOSPERMA 14. |
|
17. Scales or bristles under the nut remaining quite small, but somewhat dilated at the base; style not thickened at the base; stems usually with 1 leaf sheath above the base |
|
TRICOSTULARIA 19. |
|
16. Hypogynous scales or bristles absent |
|
|
|
18. Stems reiterately branched, leafless; spikelets .1 or 2 at the ends of the branches |
|
CAUSTIS 5. |
|
18. Stems simple or with leafy branches usually from the base; spikelets in terminal inflorescences |
|
|
|
19. Stems hollow; nut drupe-like, borne on a disk not falling off with the nut; leaves horizontally flattened, 3- ranked |
|
CLADIUM 7. |
|
19. Stems solid, pithy or transversely septate; nut not drupe-like, without a disk |
|
|
|
20. Leaves ligulate, spirally arranged, horizontally flattened; style-bases not swollen |
|
GAHNIA 11. |
|
20. Leaves not ligulate vertically flattened or terete; style-bases swollen |
|
|
|
21. Nut surmounted by the thickened style-base which is scarcely half as long as the body or almost obsolete; lowermost flower perfect |
|
BAUMEA 1. |
|
21. Nut surmounted by a conical beak nearly as long as the body; uppermost flower perfect |
|
TETRARIA 18. |
Author:
Prepared by J.P. Jessop and J. Z. Weber
|
