Aristida species

Gutiérrez, Harol, Castañeda, Roxana & Montesinos-Tubée, Daniel B., 2018, Aristida tovariana (Poaceae, Aristidoideae), a new species from the Andes of Southern Peru, Phytotaxa 362 (1), pp. 105-111 : 109-110

Key to Aristida species in Peru

1. Column of lemma present..................................................................................................................................................................2

- Column of lemma absent..................................................................................................................................................................11

2. Lemmas to 2.3–3 mm long, awns to 5–6 mm long ...................................................................... A. capillacea Lamarck (1791:156) .

- Lemmas greater than 3 mm long, awns greater than 6 mm long.......................................................................................................3

3. Annual plants......................................................................................................................................................................................4

- Perennial plants..................................................................................................................................................................................5

4. Columns 4.5–6 mm long, awns 27–40 mm long.......................................................................................................... A. chiclayensis

- Columns 7.5–8 mm long, awns 18–20 mm long.............................................................................................. A. pseudochiclayensis

5. Column twisted 2–3 times..................................................................................................................................................................6

- Column not twisted.............................................................................................................................................................................7

6. Columns (6–)14–24(–52) mm long......................................................................................................... A. riparia Trinius (1836:48)

- Columns 1.5–2.5 mm lonG................................................................................................................................................................9

7. Panicle lax, the branches divergent or appressed, not spiciform............................................................ A. laxa Cavanilles (1799:44)

- Panicle linear to linear oblong, dense, spiciform...............................................................................................................................8

8. Lateral awns poorly developed (≤ 0.5 mm long.) ....................................................... A. schiedeana Trinius & Ruprecht (1842:120)

- Lateral awns well-developed (≥ 0.5 mm long.)......................................................................... A. megapotamica Sprengel (1827:31)

9. Panicle spiciform, branches appressed; culms erect; anthers 0.9–1 mm long.................................................................. A. tovariana

- Panicle open, branches spreading; culms geniculate; anthers>1.0 mm long..................................................................................10

10. Panicle branches rigid, spikelets grouped towards the distal portion of the branches ..................................................... A. asplundii

- Panicle branches flexuous, spikelets not grouped towards the distal portion of the branches. A. ecuadoriensis Henrard (1932:307)

11. Lemma laterally compressed............................................................................................................................................................12

- Lemma not laterally compressed......................................................................................................................................................13

12. Plants annual; lemma 5–10(–11) mm long.................................................................................................................. A. adscensionis - Plants perennial; lemma 13–15(–17) mm long ................................................................................. A. murina Cavanilles (1799:44)

13. Lemma with longitudinal groove ..................................................................................................... A. circinalis Lindman (1900:13)

- Lemma without longitudinal groove................................................................................................................................................14

14. Leaf blades convolute, central awns recurved................................................................ A. torta ( Nees 1829:386) Kunth (1833:190)

- Leaf blades involute, central awns straight......................................................................................................................................15

15. Leaf blades flexuous; culms without nodes.......................................................................... A. antoniana Steudel ex Döll (1878:19)

- Leaf blades rigid (setiform), culm with nodes..................................................................................................................................16

16. Lemmas 4–5 mm long, glumes to 6–8 mm long................................................................................... A. setifolia Kunth (1816:122)

- Lemmas 8.5–10 mm long, glumes 10–12 mm long ............................................................................ A. tarapotana Mez (1921:151)