Cyperus species

Pereira-Silva, Luciana, Hefler, Sonia Marisa & Trevisan, Rafael, 2016, Cyperus tuckerianus (Cyperaceae), a new species from the Central-West Region of Brazil, Phytotaxa 284 (3), pp. 218-224 : 222-223

Key of the Cyperus species that correspond to subg. Pycreus for the Central-West Region of Brazil

1. Glumes with prominent white hyaline margins....................................................................................................... C. macrostachyos

- Glumes without hyaline margins, and if present not prominent.........................................................................................................2

2. Spikelets 3.0–5.0 mm wide; anthers 2.0– 2.4 mm long .................................................................................................. C. unioloides

- Spikelets 1.0–3.0 (–4.0) mm wide; anthers shorter than 2.0 mm.......................................................................................................3

3. Inflorescence in lax anthelodium, simple or compound, with evident rays.......................................................................................4

- Inflorescence in contracted anthelodium or monocephalous, without rays or with inconspicuous rays...........................................5

4. Achenes obovoid to elliptic; spikelets 2.3–3.2 mm wide............................................................................................. C. tuckerianus

- Achenes oblong to narrow oblong; spikelets 1.1–1.6 (–2.0) mm wide...................................................................... C. polystachyos

5. Spikelets grouped in pseudolateral inflorescences.............................................................................................................................6

- Spikelets grouped in a terminal inflorescences..................................................................................................................................7

6. Glumes yellowish brown; achenes with rounded apex .......................................................................................... C. megapotamicus

- Glumes dark brown to purplish brown; achenes with apex strongly truncate ............................................................. C. capillifolius 7. Spikelets 2.0–3.0 mm wide; rachilla wingless, achenes obovoid to ellipsoid, not truncated ........................................ C. lanceolatus

- Spikelets 1.0–2.0 mm wide, rachilla winged, achenes oblong to narrowly oblong, truncated .................................. C. polystachyos