Rex cultorum begonias, numbering 1 species and at least 4161 cultivars, are rhizomatous begonias with colorful and reflective silver, red, green, and purple toned leaves. Depending on the parentage, the leaves may be simple, maple leaf shaped, or jagged and bizarre; there is a little of everything in this group.

All Rex Cultorum types are descended from the Indian species Begonia rex that was crossed with other types of rhizomatous begonias, in fact in the 1950’s, the American Begonia Society mandated that only those plants with B. rex in their background could be called Rex cultorum.

The “Original” Rex, the species B. rex ‘Putzeys’ was at first to be a distinct species, however with the advent of molecular taxonomy it turns out there might a complex of closely related begonias, all with similar appearances that make up this species. The search for the original rex has become a search for unicorns, or Eldorado, the fabled city of gold.

The “Original” Rex, the species B. rex ‘Putzeys’ | Photo: Rick Schoellhorn

The hybrid B. ‘Flirty Girl’ is a cross between B. acetosella and B. ‘Georgia Tasker’ (a rex cultorum hybrid).

Why rex cultorum?

Because there is only one species called B. rex and while it was a parent of this type of Begonia, it was one of about 30 different species all combined to give us the plant we see today. So many parents in fact, that it was easier to give the ‘group’ a name than it was to try to keep track of who all the players were.

Rex begonias are stunning, although considered a bit difficult to grow. Once you get the hang of it, it becomes much easier, but it does take practice. Rex Cultorum begonias produce pink, white and yellow flowers about 1” in size and which can be quite spectacular.

Articles About Rex Cultorum Begonias

Images of Rex Cultorum Begonias

Begonia species that were used to create today’s Rex Cultorum cultivars

B. xanthina

B. palmata

B. hatacoa | Photo: American Begonia Society ©2006

B. annulata | Photo: John Jearrard – All rights reserved

B. tenera | Photo: 2010 Shaju,T. From The Begonian Vol.77

B. robusta | Photo: by P.B. Pelser © 2014

B. rex

B. argentea | Photo: 1859 from Journal d’horticulture pratique de la Belgique

B. decora

B. grandis | Photo: Little Prince Plants

B. diadema | Photo: of Ross Bolwell

B. beddomei | Photo: Efloraofindia ©2021

B. picta | Photo: Randy Kerr

B. cathayana | Photo: Campbell – All rights reserved

B. deliciosa

B. dregei | Photo: Chun Ming Chen

B. socotrana | Photo: doardo Scepi – All rights reserved ©2021

B. incarnata | Photo: Board of Trustees, RBG Kew ©2021

B. ×tuberhybrida

B. x amabilis | Photo: 1859 Journal d’horticulture pratique de la Belgique