Cyperus pedunculatus

Content

Description

Leaves crowded, rigid, canaliculate, often recurved, scabrid on the margins in the upper part, 4-5 mm wide at the base, very gradually narrowed into the triquetrous pungent top. Inflorescence head-like, consisting of some digitately arranged, sessile, short spikes. Stamens 3;

Distribution

Asia-Tropical, Pantropical present

Pantropical; throughout Malesia. Map by .

Taxonomy

The homology of the organ tightly clasping the nut has often been discussed: ROBERT BROWN (1810) took it for the incrassate flower- bearing glume. He was followed by nearly all later authors. KUNTH (1837) disagreed in assuming it to represent the thickened upper internode of the rachilla, but his undoubtedly correct interpretation was only sustained as late as 1922 (), whilst so recently as 1944 KÜKENTHAL stuck to the interpretation as a but slightly transformed glume hardly different from the other glumes.
From the facts mentioned below it can only be concluded that the nut is enclosed in the upper (or rather penultimate) rachilla-internode, and that the species does not belong in Rhynchosporeae, but in Cyperus as circumscribed in the present treatment.

a) The stamens are placed between the 4th glume and the ovary, not between the corky organ and the ovary; as a rule stamens in Cyperaceae are placed between the flower-bearing glume and the ovary.
b) The glumes are all many-nerved, the corky organ is nerveless.
c) The 4th glume is distinctly longer than the corky organ; in Cyperaceae the flower-bearing glumes are always the largest.
d) The corky organ bears a cucullate appendage with in its axil a short but distinct continuation of the axis; this appendage must be the 5th, vestigial glume.
e) The nut is flattened against the corky organ; trigonous nuts in Cyperaceae are always flattened against the rachilla, having an edge next the subtending glume.

Anatomical and embryological characters corroborate exclusion from Rhynchosporeae; see .

Notes

The fruits, completely hidden by the corky rachilla-internode, which is moreover wrapped in the upper glumes, are buoyant and easily dispersed by the sea. See , and .
The rhizome is fragrant; its use as an aromatic was mentioned by RUMPHIUS.
In American and African specimens the stems are usually leafy almost to the top, in Asiatic and Australian ones they are mostly well exserted from the leaves. On this ground R. BROWN distinguished the Australian plants as Remirea pedunculata. KÜKENTHAL, following BENTHAM, reduced BROWN’S species to varietal rank. As there is every gradation from included to exserted stems and no differences in spikelets, fruits, etc. exist, nomenclatural recognition seems superfluous.

Citation

KÜK. 1944 – In: Fedde, Rep. 53: 206

NAVES 1882: NOV. App.: 309

Miq. 1856 – In: Fl. Ind. Bat.: 288

BACK. 1919: p. 8. – In: Trop. Natuur: f. 15

BOECK. 1868 – In: Linnaea: 435

CAMUS 1912: Fl. Gén. I.-C. 7: 155

KÜK. 1924 – In: Bot. Jahrb.: 53

NEES 1854 – In: Hook., J. Bot. Kew Misc. 6: 29

KUNTH 1837 – In: En.: 139

Ridl. 1925 – In: Fl. Mal. Pen.: 169

PFEIFF. 1931 – In: Fedde, Rep. 29: 184

Merr. 1921: En. Born.: 63

OHWI 1942 – In: Bot. Mag. Tokyo: 209

AUBL. 1923 – In: En. Philip.: 130

HEYNE 1927 – In: Nutt. Pl.: 312

KOYAMA 1961 – In: Quat. J. Taiwan Mus.: 190

UITT. 1949 – In: Back., Bekn. Fl. Java, (em. ed.), 10: fam. 246, p. 48

K. SCH. & LAUT. 1900: Fl. Schutzgeb.: 198

VALCK. SUR. 1912 – In: Nova Guinea: 708

Clarke 1894 – In: Fl. Br. Ind.: 677

KÜK. 1944 – In: Fedde, Rep. 53: 207

STEUD. 1855 – In: Syn.: 60

Miq. 1861: Sum.: 262

AUBL. 1907 – In: Philip. J. Sc.: Bot. 103

Ridl. 1907 – In: Mat. Fl. Mal. Pen. (Monoc.): 99

Koord. 1911 – In: Exk. Fl. Java: 201

AUBL. 1922 – In: Exk. Fl. Java: f. 263

S. T. BLAKE 1948 – In: J. Arn. Arb.: 100