| 1. |
Callus up to twice the length of the spikelet axis internode |
2 |
|
Callus greater than twice the length of the spikelet axis internode |
16 | |
| 2. |
Hairs on the lemma forming a continuous indumentum, sometimes with tufts on the upper margin; leaves not disarticulating |
3 |
| Hairs on the lemma in two untidy rows, most of lemma surface glabrous and shiny, leaves often disarticulating from sheath |
8 | |
| 3. | Marginal hair tufts absent; anthers red | 4 |
| Marginal hair tufts present; anther yellow to orange | 6 | |
| 4. | Lateral lobes ±8 mm long | R. clelandii (SA) Danthonia clelandii, Notodanthonia clelandii, Joycea clelandii |
| Lateral lobes 3-6 mm long | 5 | |
| 5. | Plants weakly tufted, with a scaly rhizome; leaves flat or channelled; culms to c. 60 cm tall | R. lepidopodum (VIC) Danthonia lepidopoda |
| Plants strongly tufted, without a rhizome; leaves closely inrolled; culms commonly 1 m tall or more | R. pallidum (NSW VIC WA) Joycea pallidum, Danthonia pallida, Chionochloa pallida, Notodanthonia pallida |
| 6. | Lateral lobes shortly awned | R. longifolium (NSW VIC WA QLD) Danthonia longifolia |
| Lateral lobes not or minutely awned | 7 | |
| 7. | Leaf-sheaths glabrous | R. semiannulare (NSW VIC TAS SA WA) Danthonia semiannularis, Notodanthonia semiannularis |
| Leaf-sheaths distinctly pilose | R. gracile(NSW VIC WA QLD) Danthonia gracilis, Notodanthonia gracilis |
| 8. | Spikelet axis internode 1/3-1/2 lemma length | 9 |
| Spikelet axis internode up to 1/4 lemma length | 10 | |
| 9. | Lemma c. 2.5 mm long, ±hairy | R. pumilum (NSW) Erythranthera pumila |
| Lemma c. 2 mm long, glabrous | R. australe (NSW VIC TAS) Erythranthera australis |
|
| 10. | Lemma with a complete transverse row of hair tufts just below sinus | 11 |
| Lemma with marginal and/or dorsal tufts of hair below sinus sometimes forming an interrupted row | 13 | |
| 11. | Body of lemma 3 mm long or more | R. pauciflorum (NSW) Notodanthonia pauciflora, Danthonia pauciflora |
| Body of lemma 1.25-3 mm long | 12 | |
| 12. | Inflorescence ±loose; awn with several basal twists; lemma with sparse hair-tufts | R. dimidiatum (VIC TAS) Notodanthonia dimidiata, Danthonia dimidiata |
| Inflorescence ±dense; awn with one basal twist; lemma with dense hair-tufts | R. fortunae-hibernae (TAS) Danthonia fortunae-hibernae |
|
| 13. | Lateral lobes distinctly longer than body of lemma | R. nudiflorum (NSW VIC TAS) Notodanthonia nudiflora, Danthonia nudiflora |
| Lateral lobes shorter than to slightly longer than body of lemma | 14 | |
| 14. | Lateral lobes shorter than to slightly longer than body of lemma | R. dimidiatum (VIC TAS) Notodanthonia dimidiata, Danthonia dimidiata |
| Lateral lobes shorter than body of lemma | 15 | |
| 15. | Lemma almost glabrous and shining except for sparse marginal hairs | R. nitens (TAS) Danthonia nitens |
| Lemma slightly hairy towards base as well as sparse marginal hairs, not shining; culms not stiffly erect | R. nivicolum (NSW VIC TAS) Notodanthonia nivicola, Danthonia nivicola, Danthonia pulvinorum, Rytidosperma pulvinorum |
|
| 16. | Lemma with hairs only in distinct transverse rows of tufts on back | 17 |
| Lemma with hairs scattered uniformly over back instead of or as well as hairs in tufts | 35 | |
| 17. | Lemma with a complete transverse row of hair-tufts just below sinus | 18 |
| Lemma with marginal and/or dorsa tufts of hair below sinus sometimes forming an interrupted row |
31 | |
| 18. | Lemma without a row of hair-tufts above callus | R. laeve (NSW VIC TAS SA) Danthonia laevis, Notodanthonia leavis, Austrodanthonia laevis |
| Lemma with a row of hair-tufts above callus |
19 | |
| 19. | Outer margins of lateral lobes with auricles | R. auriculatum (NSW VIC SA) Danthonia auriculata, Notodanthonia auriculata, Rytidosperma auriculatum, Austrodanthonia auriculata |
| Outer margins of lateral lobes without auricles | 20 | |
| 20. | Body of lemma golden brown at maturity | R. duttonianum (NSW VIC SA) Danthonia duttoniana, Notodanthonia duttoniana, Rytidosperma duttonianum,Austrodanthonia duttoniana |
| Body of lemma pale at maturity | 21 | |
| 21. | Body of lemma 1.25-3 mm long | 22 |
| Body of lemma 3 mm or more long | 24 | |
| 22. | Lateral lobes less than 6 mm long | R. setaceum (NSW VIC TAS SA WA) Danthonia setacea, D. setacea var. breviseta, Notodanthonia setacea, Rytidosperma setaceum, Austrodanthonia setacea |
| Lateral lobes 6-10 mm long | 23 | |
| 23. | Setae of lateral lobes 2-4 mm long | R. monticolum (NSW VIC) Danthonia monticola, Notodanthonia monticola, Rytidosperma monticola, Austrodanthonia monticola |
| Setae of lateral lobes 4-6 mm long | R. setaceum (NSW VIC TAS SA WA) Danthonia setacea, D. setacea var. breviseta, Notodanthonia setacea, Rytidosperma setaceum, Austrodanthonia setacea |
|
| 24. | Setae much shorter than flat portion of lateral lobes | 25 |
| Setae ± as long as flat portion of lateral lobes | 28 | |
| 25. | Palea 7-8 mm long, ±equaling flat part of lemma lateral lobes | R. indutum (NSW VIC SA TAS QLD) Danthonia procera, Notodanthonia procera, Rytidosperma procerum, Austrodanthonia induta |
| Palea to 6 mm long, shorter than flat part of lemma lateral lobes | 26 | |
| 26. | Palea broad, 1-3 times as long as wide | R. oreophilum (NSW VIC) Austrodanthonia oreophila |
| Palea narrow, 3-5 times as long as wide | 27 | |
| 27. | Lemma lobes 6-10 mm long; callus of upper florets long and stipe-like | R. tenuius (NSW VIC SA TAS SA QLD) Danthonia purpurascens, Notodanthonia tenuior, Rytidosperma tenuis, Austrodanthonia tenuior |
| Lemma lobes 5-6 mm long; callus of upper florets short | R. diemenicum (TAS) Danthonia diemenica, Notodanthonia diemenica, Austrodanthonia diemenica |
|
| 28. | Body of lemma ± 0.75 mm wide | R. acerosum (WA) Danthonia acerosa, Notodanthonia acerosa, Austrodanthonia acerosa |
| Body of lemma at least 1.5 mm wide | 29 | |
| 29. | Palea up to 3 mm wide | R. erianthum (NSW VIC SA) Danthonia eriantha, Notodanthonia eriantha, Austrodanthonia eriantha |
| Palea less than 2 mm wide | 30 | |
| 30. | Leaves 5-10 cm long, thick and rigid |
R. alpicolum (NSW VIC) Danthonia alpicola, Notodanthonia alpicola, Austrodanthonia alpicola |
| Leaves 10-30 cm long, not thick and rigid |
R. caespitosum (NSW VIC TAS SA WA) Danthonia caespitosa, Notodanthonia caespitosa, Rytidosperma caespitosum, Austrodanthonia caespitosa |
|
| 31. | Inflorescence 3-5 cm long | 32 |
| Inflorescence 5-15 cm long | 33 | |
| 32. | Leaves glabrous; lower glume 9-13-nerved | R. remotum (TAS) Danthonia remota, Austrodanthonia remota |
| Leaves mostly pilose; lower glume 5-9-nerved | R. pilosum (NSW VIC TAS SA WA) Notodanthonia pilosa, Austrodanthonia pilosa, Notodanthonia pilosa var. paleacea, Danthonia pilosa, Rytidosperma pilosum var. paleaceum |
|
| 33. | Spikelets 4-6-flowered | R. penicillatum(NSW VIC TAS SA WA) Danthonia penicillata, Notodanthonia penicillata, Austrodanthonia penicillata |
| Spikelets 7-10-flowered | 34 | |
| 34. | Lateral lobes with setae | R. racemosum var. racemosum (NSW VIC TAS SA WA QLD) Danthonia obtusata, Notodanthonia racemosa, Austrodanthonia racemosa |
| Lateral lobes with short points | R. racemosum var. obtusatum (NSW QLD) Danthonia racemosa var. obtusata, Notodanthonia racemosa var. obtusata, Austrodanthonia racemosa var. obtusata |
|
| 35. | Central awns not or scarcely exceeding lateral lobes | R. geniculatum (VIC TAS SA) Danthonia geniculata, Notodanthonia geniculata, Austrodanthonia geniculata |
| Central awns much exceeding lateral lobes | 36 | |
| 36. | Lateral lobes shorter than body of lemma | 37 |
| Lateral lobes equal to or longer than body of lemma | 38 | |
| 37. | Lateral lobes c. 7 mm long | R. popinensis (TAS) Austrodanthonia popinensis, Danthonia popinensis |
| Lateral lobes 2-4 mm long | R. carphoides (NSW VIC TAS SA) Danthonia carphoides, Danthonia carphoides var. angustior, Austrodanthonia carphoides, Notodanthonia carphoides, Rytidosperma carphoides var. angustius |
|
| 38. | Lateral lobes 2-3 times as long as body of lemma | 39 |
| Lateral lobes less than twice as long as body of lemma or latter at least 3mm long | 40 | |
| 39. | Lemma hairs ± all uniformly scattered; glumes 5-8 mm long | R. geniculatum (VIC TAS SA) Danthonia geniculata, Notodanthonia geniculata, Austrodanthonia geniculata |
| Lemma hairs in rows of tufts as well as scattered; glumes 8-11 mm long | R. monticola (NSW VIC) Danthonia monticola, Notodanthonia monticola, Austrodanthonia monticola |
|
| 40. | Lemma hairs uniformly short (about 0.5 mm long) except for those directly below sinus | 41 |
| Lemma hairs grading from 1mm long at base to 5 mm long at apex | 43 | |
| 41. | Body of lemma less than 3 mm long | R. setaceum (NSW VIC TAS SA WA) Danthonia setacea, Danthonia setacea var. breviseta, Notodanthonia setacea, Austrodanthonia setacea |
| Body of lemma at least 3 mm long | 42 | |
| 42. | Lemma hairs ± all uniformly scattered | R occidentale (WA) Danthonia occidentalis, Notodanthonia occidentalis, Austrodanthonia occidentalis |
| Lemma hairs mostly in rows of tufts | R. alpicolum (NSW VIC) Danthonia alpicola, Notodanthonia alpicola, Austrodanthonia alpicola |
|
| 43. | Central awn reflexed or loosely twisted at base | 44 |
| Central awn strongly twisted at base | 45 | |
| 44. | Palea broadly obovate, obtuse; body of lemma 4-6 mm long | R. richardsonii (NSW VIC SA) Danthonia richardsonii, Notodanthonia richardsonii, Austrodanthonia bipartita richardsonii |
| Palea lanceolate-elliptic, acute; body of lemma 3-3.5 mm long | R. bipartitum (NSW VIC SA QLD) Danthonia linkii, Notodanthonia bipartita var. linkii, Rytidosperma linkii var. linkii, Austrodanthonia bipartita |
|
| 45. | Body of lemma 3-4 mm long; palea less than 5 mm long | R. fulvum (NSW VIC SA) Danthonia linkii var. fulva, Notodanthonia bipartita var. fulva, Rytidosperma linkii var. fulvum, Austrodanthonia fulva |
| Body of lemma 4-5.5 mm long; palea 6-8 mm long | R. indutum (NSW VIC TAS SA QLD) Danthonia procera, Notodanthonia procera, Rytidosperma procerum, Danthonia induta, Notodanthonia induta, Austrodanthonia induta |
Key to Rytidosperma derived from Vickery 1956, as Danthonia; Linder and Verboom 1996; Linder 1997 as Austrodanthonia, Joycea, Notodanthonia. Nomenclature from Linder et at 2010.
Taxonomic name: