Begonia promethea (syn. beccarii) was originally discovered in 1906 by Henry Ridley, who said that it was “perhaps the most worthy of cultivation among the Bornean species.” More than 100 years since it’s discovery, it was rediscovered by Michael Lo (who posts about his forays on facebook and instagram). Promethea and beccarii are now synonymous, and, per the etiquette of scientific nomenclature, the original name is the one that sticks.
B. promethea is in the section Petermania and is only found at three localities, including ones in Sarawak, Malaysia, and West Kalimantan. In the recently published paper describing the taxonomic status of this species, (found here), the authors advise an IUCN category of Endangered based on its small area of occupancy of under 500 square kilometers. Additionally, none of the three localities exist within protected areas.
Interestingly, in this paper, it describes the plants as having leaves: “2-3, rarely 4, the remains of rotten old leaves sometimes still present, flat on the rock surface.” I’ve not had this species very long but did observe a die-off of older leaves when it reached about four or five leaves. It seemed to be a response to too much humidity, although now I’m wondering if it could be part of this species natural growth rhythm. The habitat is further described as being lowland, “50-150 m elevation, growing in wet, shaded, and almost vertical sandstone cliffs or basalt cliffs with water spray, sometimes in direct sunlight. Very local but can densely cover the rock face in small patches….Ridley (1906) had noted that plants he grew in the Botanic Gardens, Singapore ‘grew very readily and flowered in December and January..”