Maranta leuconeura 'Erythroneura'

Where it comes from

Kew gives Maranta leuconeura as native to central and eastern Brazil — three regions, the Northeast, the Southeast and the West-Central.¹ NC State’s page says Brazil, Colombia and parts of Mexico, and NYBG says Central and South America; both are wider than Kew has it, and Kew is the one to follow.²³

The red-veined plant itself comes from a greenhouse. Its name was published from cultivated material, and nobody has recorded it growing wild — which is the whole of the naming problem below.

Naming and description

This is not a variety, whatever the label says. Kew accepts Maranta leuconeura É.Morren and no infraspecific taxa at all — no varieties, no subspecies. M. leuconeura var. erythroneura sits in the species’ synonym list as a heterotypic synonym.¹⁴

The evidence that it is a cultivar wearing Latin is unusually clean. G. S. Bunting published the name in Baileya 14: 45 in 1966⁵ — Baileya being a journal of horticultural taxonomy — and IPNI’s type field for the name reads “Described from cultivated material”.⁵ A varietal name erected in 1966 from a plant that only exists in cultivation is exactly the pattern the Cultivated Plant Code was written to sort out.

Horticulture got there first, in fact: UF/IFAS’s production guide has listed it as M. leuconeura ‘Erythroneura’, in cultivar quotes, since 1991, alongside ‘Kerchoviana’, ‘Leuconeura’ and ‘Kerchoviana Minima’.⁶ This page follows Kew and UF/IFAS. The RHS keeps varietal rank in circulation but is not consistent about it — its record for var. erythroneura ‘Lemon Lime’ is marked “Unresolved”, while var. leuconeura ‘Fascinator’ is marked “Accepted”.⁷⁸

The leaf is what you buy it for: deep olive with a pale central zone, and bright red veins running out to the margin in a herringbone. The markings are pigment in the leaf, not a trick of the light, and they wash out in too much sun.

Fun facts

• The prayer movement has a hinge, and it is not where you would guess. The leaf folds on a pulvinus — a swelling that moves the leaf by pumping water in and out of its cells rather than by growing. In Marantaceae that hinge sits at the summit of the petiole, right where the blade joins,⁹ which is a different place from the legumes where all the mechanism was worked out.
• Almost everything published about how nyctinasty works was measured on something else. I read three mechanism reviews and not one of them mentions Marantaceae, Maranta or prayer plants at all.¹⁰¹¹¹² Every model species is a legume — Samanea, Albizia, Mimosa, Medicago. The potassium-flux account is very likely right here too, but nobody has shown it in this plant, and one of those reviews notes the chemical signals are genus-specific. So: the clock sets the timing and light supplies the cue,¹⁰ and the details are borrowed.
• The distilled-water rule is aimed at the wrong tap. The hobby’s fluoride-sensitivity warning traces to a published list of fluoride-sensitive plants — and Maranta, Marantaceae and Calathea appear nowhere on it.¹³ Dracaena and spider plant do. But fluoride injury in Maranta is separately real: Penn State lists tip burn with phosphate fertiliser and fluoride toxicity among its causes, and the fix it names is to avoid superphosphate and perlite, not to change the water.¹⁴ Rainwater will not hurt; changing the potting mix is the better-evidenced move. The chlorine-and-chloramine half of the same folklore is weaker still: an extension answer citing the EPA says the levels in drinking water are not toxic to plants.¹⁵