Thanks for posting.
However I think things along the way have become a little confused,- perhaps the facts having been 'lost in translation'.
What is pictured there is in fact not any form of corn, but rather the grain 'mabela'.
Mabela is used extensively in the region, even today, to make African beer .
Mabela is also used to make a porridge, called Maltabela. This is available in all South African supermarkets, usually in the form of an 'instant' porridge.
I know that the Empress was very interested in things horticultural and took poppy seeds with her on the tour, to be planted on various graves she visited on the battlefield as well at the Ityotyosi, where her son fell. It was there that she was left alone for the night on her solitary vigil until sunrise.
Eugenie also arranged to have a clump of Tamboekie grass dug up at the site were her son fell. This was taken back to England by her and lovingly nurtured for many years in the Palace nursery. It was seen there many years later by her visitors.