Polka dot begonia vs Rex begonia

Begonia maculata · Begonia rex

Mature size: Polka dot begonia reaches about 48 inches; Rex begonia tops out near 18. Buying the wrong one for a shelf means rehoming it in a year.

Why these two get mixed up

Both are Begonia, so they arrive on the same shelf under near-identical labels and are routinely swapped in the trade.

Polka dot begonia (Begonia maculata) — **Polka dot begonia** — Begonia maculata. Photograph by Cliff from I now live in Arlington, VA (Outside Washington DC), USA, Wikimedia Commons , CC BY 2.0.

Rex begonia (Begonia rex) — **Rex begonia** — Begonia rex. Photograph by NasserHalaweh, Wikimedia Commons , CC BY-SA 4.0.

	Polka dot begonia	Rex begonia
Scientific name	Begonia maculata	Begonia rex
Family	Begoniaceae	Begoniaceae
Light floor	Medium	Low
Water	5–10 days	5–10 days
Humidity floor	45%	50%
Mature height	12–48 in	8–18 in
Habit	upright	clumping
Growth rate	fast	moderate
Difficulty	Moderate	Demanding
Toxic to pets	Yes	Yes
Typical price	$15–45	$12–40

Highlighted cells are where the two actually differ. Everything else they share.

The differences that matter

Mature size

Polka dot begonia reaches about 48 inches; Rex begonia tops out near 18. Buying the wrong one for a shelf means rehoming it in a year.

Light

Rex begonia tolerates low light; Polka dot begonia needs medium as a floor. Put the second in the first's spot and it stretches and declines.

Habit

Polka dot begonia grows upright; Rex begonia grows clumping. That decides where each one physically works.

Which should you buy?

In a dim room, take Rex begonia.
If you forget to water, take either.
If it is your first plant, take Polka dot begonia, at 3 of 5.
For a small shelf, take Rex begonia, which stops around 18 inches.

Full entries

Polka dot begonia — care fields with sources, toxicity with every authority consulted, propagation and diagnosis. Rex begonia — the same.

Sources

This database's own care records for Begonia maculata and Begonia rex — every figure compared above.
Royal Botanic Gardens Kew, Plants of the World Online — accepted names and families for Begonia maculata and Begonia rex
ASPCA Animal Poison Control — toxicity classification for both, cited on each species entry
Photographs: Wikimedia Commons, individually credited and licensed above

Compiled and edited by Tony Valcarcel · 2026-09-12
Every comparison above is drawn from a recorded field. Where the honest distinguisher is visual we show both photographs rather than describing a leaf we have no field for. How this is sourced.