One species · 4 forms

Alternanthera reineckii

Also known as AR, Scarlet temple, Telanthera reineckii, Alternanthera reineckii 'Rosaefolia', Alternanthera reineckii 'Bronze'

FreshwaterStemCuttingsSide shoots

Alternanthera reineckii (Alternanthera reineckii) — Aquarium Plants Factory · Used with permission

Care at a glance

Light: Medium light
CO2: CO₂ beneficial
Temperature: 72–82°F; 22–28°C
Max height: 19.7 in; 50 cm

Growth rate: Medium
Placement: Midground
Type: Stem
pH: 6.0–7.5
Hardness: 3–12 dGH
Spread: 5.9 in (15 cm)
Nutrient uptake: Root + water column
Growth region: Submersed or emersed
Difficulty: Medium
Family: Amaranthaceae
Origin: South America (Brazil, Paraguay, Argentina, Bolivia, Uruguay)

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One setup covers every form on this page.

Overview

Alternanthera reineckii is one of the most popular red plants and among the more forgiving ones. It is a midground stem plant of medium difficulty.

Did you know

Iron drives the color of Alternanthera reineckii as much as light does. Starved of iron, its leaves fade to pale pink or green however bright the lighting. Dedicated iron dosing is the standard trick for keeping it red.

Caring for Alternanthera reineckii

Plant single stems a little apart in the midground so light reaches the whole length of each one. Strip the lower leaves before you push each stem into the substrate.

Alternanthera reineckii grows in medium light, and strong light with CO2 and iron brings out the deepest red. It grows without CO2 and can still color up reasonably, but growth slows and it becomes more prone to algae. It takes nutrients through both roots and leaves, so pair root tabs or a rich substrate with a liquid fertilizer that includes iron. Keep it at 72 to 82°F (22 to 28°C).

It grows at a moderate pace rather than fast. Trim the tops and replant them to bush out the group, and plant side shoots on their own once they have a few leaves.

Lower leaves drop when the upper growth shades them. Keep the stand thinned so light reaches down the stems.

Most red plants demand high light to color up; reineckii carries red pigment by default and keeps it under moderate light. Iron and decent light deepen the wine tones, and CO2 tightens the growth, but none of it is required the way it is for a red rotala.

The dwarf form stays around ten centimeters and branches into low red cushions, which put reineckii in the foreground for the first time. Rosanervig adds pale veins over pink leaves, a nursery selection with the same habit as the standard plant, and Green swaps the red for olive on an otherwise identical stem. Lilacina grows taller, up to 60 cm, with longer wine-red leaves over purple undersides.

Good to know

Alternanthera reineckii belongs to the amaranth family, Amaranthaceae, and was historically traded under the genus name Telanthera. Shops shorten it to AR, and it also sells as scarlet temple. Its leaves are green to olive on top and pink to deep red underneath. Anthocyanin and carotenoid pigments concentrated on the leaf undersides make the red. Trade cultivars such as 'Rosanervig', 'Pink', 'Mini' and 'Variegated' are all forms of this one species.

In the wild

Alternanthera reineckii is native to South America, across southern Brazil, Paraguay, northern Argentina, Bolivia and Uruguay. It grows in marshes, on stream banks and on seasonally flooded ground. It lives both submersed and as a semi-aquatic marsh plant.

Common questions

Why are the lower leaves falling off?

Shading. The canopy steals the light and the plant abandons what it cannot power. Trim the tops, replant them, and keep the stand thinned so light reaches down the stems.

Does AR need CO2?

No. It grows and stays red without it; CO2 just makes the growth denser and faster. The Mini form in particular benefits if you want a tight carpet-like cushion.

Does Alternanthera reineckii need to be planted in the substrate?

Yes. Strip the leaves from the lower part of each stem, then push the stems into the substrate one at a time, a little apart.

How much light does Alternanthera reineckii need?

Alternanthera reineckii wants medium light. A light sold for planted tanks covers it.

Does Alternanthera reineckii need root tabs?

They help. Alternanthera reineckii takes nutrients through both its roots and its leaves. Root tabs near its roots and a liquid fertilizer cover both.

How do you propagate Alternanthera reineckii?

Alternanthera reineckii propagates by cuttings and side shoots. Cut off the top of a stem and replant it, and the stump left behind grows new shoots. Cut a side shoot off once it has a few leaves and plant it on its own.