Aglaonema….Leaf with less than 10 pairs of lateral veins
Dieffenbachia….Leaf with more than 10 pairs of lateral veins
 
Yes the two genera can be separated on the basis of lateral veins easily. There are other characters which can be seen when flowers appear, but as we now these foliage plants rarely come to flower in pots. If the plant is in flower these things can further help:
1. The spathe (large sheath surrounding the inflorescence) is persistent in Dieffenbachia, falls off soon in Aglaonema
2. Female flowers in Dieffenbachia have staminodes (sterile stamens), these staminodes are absent in Aglaonema
3. Stamens are united in Dieffenbachia, free in Aglaonema
4. Ovary is 2-3 celled in Dieffenbachia, 1-2 ceeled in Aglaonema. 
 

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Indonesia .. may be Dieffenbachia oerstedii but not sure…  Dieffenbachia Indonesia – efloraofindia | Google Groups

 

 

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FW: BEWARE…: Some light, please!


 
Thanks from Panama on the subject of aglaonema vs. dieffenbachia: My name is … and I belong to the Veranera Garden Club, located in Penonome city, province of Cocle, Republic of Panama. I take this opportunity to thank you for helping me with a question we have had for some time. Let me explain.
One of the most popular families that we exhibit when having our garden club exhibitions are of the Araceae family. Now with the new types of aglaonemas and dieffenbachias, we are having some difficulty determine what they are. Although I am not a judge, I really enjoy looking for the names not only in the Tropica and Exotica books but in the Internet, thanks to the photographs available. Judges are those members that have obtain a certificate from the National Garden Clubs to judge horticulture and floral design. Having said that, I have been having difficulty determining which is which. Now, with the answer you provided on 27/ll/ll, which reads:
Aglaonema….Leaf with less than 10 pairs of lateral veins
Dieffenbachia….Leaf with more than 10 pairs of lateral veins
I feel you have helped me totally with the situation.


Just one more example of how interactions on this group benefit others.
I provided additional information in my reply as under
Thanks …

I happy that my writings in different Internet forums can benefit people like you. Yes the two genera can be separated on the basis of lateral veins easily. There are other characters which can be seen when flowers appear, but as we now these foliage plants rarely come to flower in pots. If the plant is in flower these things can further help:
1. The spathe (large sheath surrounding the inflorescence) is persistent in Dieffenbachia, falls off soon in Aglaonema
2. Female flowers in Dieffenbachia have staminodes (sterile stamens), these staminodes are absent in Aglaonema
3. Stamens are united in Dieffenbachia, free in Aglaonema
4. Ovary is 2-3 celled in Dieffenbachia, 1-2 ceeled in Aglaonema.