It has been very often confused with H. reinwardtii in the past. The differences are following: H. coarctata has tubercles smaller and more smoothly rounded, whereas in H.reinwardtii they are frequently large and tend to be flattened and whiter. But I have seen some plants from the area mentioned above and I wasn´t able to distinguished what is H. coarctata and what is already H. reinwardtii.
Janet, you are so great at identifying plants!! The one in that first link (H. coarctata) sure looks like a close match!
Thank you Janet 
