Evan,
In my experience, having seen blooms on the plumbea, the 'sarawakensis dark' and macrorrhizos types, I can state with confidence that the first two have similar inflorescences which are more similar to something I would expect from a cross between A. sarawakensis and A. macrorrhizos. Neither of them is like a true macrorrhizos inflorescence. So it may be that my 'sarawakensis dark' actually has some sarawakensis genes in it after all, but so might the plumbea. If so, that might also explain why the two plants are sterile.
To make things more fun, there is a genuine A. marcrorrhizos black type with all black leaves, veins and petioles. I have developed one like that from a cross of several macrorrhizos types, including the "blackstem" mac as one of the parents. However, the black leaves did not come from the "blackstem" mac but from another plant that did not have black leaves, but ones with a somewhat brownish cast.
LariAnn
