Discussions with a friend challenged my understanding of some aspects of US rice production. I had focused on California rice for most of my earlier research and really, if the truth is to be known, discounted most of the rest of the country. My understandings were not all wrong but some generalizations where flat out incorrect and this led to other beliefs being wrong as well.
Most of the rice grown in California is medium grain while most of the rest of the country grows predominantly long grain rice. This fact led to my incorrect conclusion that most of the country grows Indica rice; NOT TRUE. As it turns out very little of the rice grown in the US is actually Indica rice. So, what is all this long grain rice that is being grown? It is tropical Japonica; sometimes known as Javanica. I prefer to use Javanica but this term is becoming less and less common. Anyway, tropical Japonica comes in both long and medium grain forms.
So, while being wrong about most states growing Indica, it is true that there is a distinct difference between the rice grown in most rice producing states and California. Most rice grown in California is Japonica while most rice grown in the other major rice producing states is tropical Japonica; a distinctly different rice. Even the medium grain rice grown in these states tends to be tropical Japonica.