This particular type of Begonia is commonly known as Star Begonia often identified as a Gryphon Begonia due to the majestic look of the foliage display. Alternatively it's also known as Pegasus Begonia, all these variants and types are basically labelled as Begonia heracleifolia.
I understand there are so many cultivar and hybrids from this particular type which is rather confusing as some of them do revert back to their parentage features given the growing conditions. Hence the identification purpose is very much challenging rather its more identified by begonia plant enthusiast seeking different variations and pattern rather than specific name & identification. There are easily 300-500 different types and variants of this particular Star Begonia - some are already labelled and identified but mostly are lost and generally labelled as Star Begonia / Begonia heracleifolia.
The Main Characteristics here I want to emphasise is the strong Black Borders which appears along the Foliage Lobed Pattern. This begonia heracleifolia has the black borders which are prominent and show strong visibly along the leaf perimeter and also the black is fully cover on the leaf surface with slight green tones appears on the veins.
This one is very similar to the Begonia Chivalry except for the grandeur leaf formation that is more on the star shape. The dark veins are more pronouns with the green marbled tones in between the veins.
Begonia Common Names and Images