Oryza

1.

Ligules of lower leaves to 6 mm long 2
Ligules of lower leaves 15-45 mm long 3
   
2. Spikelets 6.5-8.4 mm long O. australiensis (NT WA QLD)
Spikelets 3.7-6.4 mm long O. officinalis (NT QLD)
   
3. Spikelets persistent *O. sativa (NT WA QLD)
Spikelets deciduous 4
   

4.

 5.

   
Annual; awns c.7.5 cm long*; seed to xx mm long O. meridionlonalis (WA. NT QLD)
Perennials; seed to xx mm long 5
Anthers 0.8-2.2 mm long, inflorescence closed; awns c.10 cm long* O. meridionalis Jpn2 (QLD)
Anthers 4-6.2 mm long; inflorescence open; awns c.7.5 cm long* O. rufipogon Jpn1 (NT WA QLD)
   

Key to Oryza derived from Duistermaat 1987; Veldkamp 1991a; Lu et al. 2000; Ishikawa (pers.comm.)

* Duistermaat has the awns as up to 110 mm long for O. rufipogon and 70-120 mm long for O. meridionalis. Also to be distinguished morpholoigically are the Asian form of O. rufipogon and the Asian species O. nivara (placed in synonymy with O. sativa by Duistermaat and with O. rufipogon by Kew).

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith