Results – Dichotomous Key to the Specimens
The following Key applies to the specimens used in this study only, and is derived from the character ranges identified in the Boxplot analysis, Fig. RD6, the taxa referred to here are those identified by cluster analysis, Fig. RD4, using quantitative characters only.
Because of the complexity of these taxa, it is generally more reliable to use a combination of characters at each dichotomy. The key below lists the characters in order of preference, character numbers refer back to those measured and shown in the tab Characters. A specimen should comply with all the characters in any couplet.
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Couplets |
Because of the complexity of these taxa, it is generally necessary to use a combination of characters to identify them to groups. In the key below, the characters are listed in order of preference, character numbers are in brackets. A specimen should comply with all the characters in any couplet. |
Go To Couplet |
Groups remaining |
|
1a |
B1s ≥ 80mm (2); glumes ≥ 2.5mm (30); spikelets always narrowly elongate (26); long R2s absent (50); |
2 |
5, 6 |
|
1b |
B1s ≤ 80mm (2); glumes ≤ 2.5mm (30); spikes may be narrowly elongate or otherwise (26); long R2s present or absent (50) |
3 |
1,2,3,4 |
|
2a |
B1s ≥ 100mm (2); short R2s 0-2 (48); total no. spikes (T R2s) ± 2 |
=5 |
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|
2b |
B1s ≤ 100mm (2); short R2s 4 or more (48); total no. spikes (T R2s) ± 5 |
=6 |
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|
3a |
No R1’s few, ≤ 40 (46); spikelets cylindrical (26); stem sharply triquetrous (45) |
=4 |
|
|
3b |
No R1’s many, ≥ 40 (46); spikelets ovate to lanceolate, never cylindrical (26); stem usually bluntly trigonous |
4 |
1,2,3 |
|
4a |
No. of spikelets on one side of spike ≥ 16 (12); R1s ≥ 300mm (5); spikes ≤ 8mm long (11) |
=3 |
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|
4b |
No. of spikelets on one side of spike < 16 (12); R1s usually ≤ 340mm and often ≤ 250mm (5); spikes usually ≥ 8mm long (11) |
5 |
1,2 |
|
5a |
Longest R2s rarely ≥ 15mm (51); P1s usually ≤ 34mm long (9); P2s usually ≤ 3.5mm (21); B2s 80-100mm, rarely longer or shorter (19) |
= 1 |
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5b |
Longest R2s usually ≥ 18mm (51); P1s usually ≥ 34mm long (9); P2s usually ≥ 3.5mm (21); B2s usually ≤ 80mm, occasionally longer (19) |
= 2 |
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Fig. RK1. Dichotomous key to study specimens, based upon the groups identified by cluster analysis. |
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