There is an image of this cultivar on the Hosta Library. From the photo on the HL website, it appears to be a large size hosta with dark green leaves and white streaked variegation. This non-registered cultivar was originated by Bev and Dave Stegeman of Indiana. 

Jambo! is a Swahili greeting or salutation with an exclamation mark. It is similar in meaning to the English word Hello!.