Anthurium plants go by a number of evocative names, including “painter’s palette” and “flamingo lily.”
The subspecies we’re going to focus on in this article, Anthurium clarinervium, has the comparatively prosaic common name of “velvet cardboard.”
But don’t let the name fool you–there’s nothing boring about this unusual houseplant.
Its beautiful foliage and relatively compact habit make it a great plant for smaller spaces or terrariums, and a long-term plant companion if you are willing to learn proper Anthurium clarinervium care.
Anthurium Clarinervium Background
Anthurium clarinervium features large heart-shaped leaves are light green below and dark green above with bright white veining.
Its common name, velvet cardboard, comes from the soft, fuzzy texture and the cardboard-like stiffness of these leaves.
You can see the hazy sheen on this closeup photo:
Unlike many other specialty houseplants, Anthurium clarinervium is a naturally occurring subspecies, not a greenhouse-developed cultivar.
It is native to southern Mexico, where it grows on limestone outcroppings as an epipetric or lithophytic plant.
Its growth pattern is similar to that of the tree-borne (epiphytic) Philodendron Splendid, except that where a Philodendron sprouts in midair from a tree branch, Anthurium clarinervium seedlings anchor themselves in the crags limestone outcroppings.
They create leaves first to harvest sunlight, followed by roots that cling to the limestone and mine its thin, rocky soils for nutrients.
These limestone outcroppings occur on slopes in the rainforest, so although it doesn’t need rich soil, Anthurium clarinervium still requires filtered sunlight, warm temperatures, and high humidity.
The Anthurium clarinervium flower is tiny compared to the “flamingo flower” Anthurium varieties.
These bright-red varieties are very popular, and they may be what first springs to mind when you think of Anthurium:
Anthurium clarinervium do have the characteristic flower spike (“spadix”) rearing up from a horizontal petal-like leaf (“spathe”). But they are small and insignificant, especially when compared to their flamingo flower brethren.
And also unlike other Anthuriums, which are typically vining and can grow to a monstrous ten feet tall, clarinervium is very well behaved, topping out at two feet high by three wide.
Where to Buy Anthurium Clarinervium
A velvet cardboard Anthurium can be tough to find even in the vast expanse of the Internet.
But, as ever, Etsy is a wonderful resource for buying unique and uncommon houseplants. You can find some beautiful plants here on Etsy. A few specific Etsy shops we recommend are:
Anthurium Clarinervium Care
If you’re lucky enough to get your hands on an Anthurium clarinervium, you’ll want to take top-notch care of your new prize.
Here’s how you can nurture your plant and enjoy it for years to come.
Appropriate pot size and type
The size of your Anthurium clarinervium plant should dictate the size of pot you place it in.
Choose a pot that is either slightly larger than the root ball or measure the height of the plant from the soil line to the top leaf and divide that number three. The number you end up with, in inches, is the diameter of an ideal pot for that plant.
Remember that these plants grow literally on the sides of rocks, so while the soil doesn’t have to be rich in organic matter, it absolutely needs to be well-draining and porous.
To ensure this, you can amend regular potting soil with perlite or vermiculite to lighten it.
But another great option for the velvet cardboard Anthurium is orchid bark. This mimics the oxygen-rich and nutrient-poor environment of a limestone outcropping surprisingly well!
Similarly, this plant does not need much fertilizing to get by. Use a fertilizer like Down to Earth All-Purpose that is high in nitrogen, which will support healthy and lush foliage.
Apply every four to weeks in spring and summer, and every six weeks in fall and winter.
Anthurium clarinervium needs well-filtered sunlight that is not too bright.
Don’t keep it too close to bright windows, and don’t place it under grow lights, as either situation will end up scorching its delicate leaves.
This Anthurium does well in a north-facing window, or a few feet back from an east-facing window and screened by furniture or another houseplant.
Water and Humidity
Watering Anthurium clarinervium can be a bit tricky. It doesn’t like to be sopping wet, but its exposed epiphetric roots tend to dry out, which is also suboptimal.
Note: Allow the first inch of soil or bark to dry out between waterings. Don’t guess–test this by actually pushing your fingertip into the soil.
Too much or too little water kills a lot of houseplants. (And remember to invest in a plant saucer to prevent overflow from ruining your carpet or furniture.)
You also need to provide high levels of humidity for this plant in order to keep its foliage green and healthy. You can do this actively by placing a plant humidifier nearby.
Or you can try one of these passive methods:
- Group with other houseplants to make a little microclimate.
- Put a jar or bowl of water nearby.
- Place the pot on a tray of damp pebbles. (Change water regularly to prevent gnats.)
- Keep your velvet cardboard in a humid room in your house, like a kitchen or bathroom.
Misting is not appropriate for this plant because its fuzzy leaves will take too long to dry, inviting disease. You should also make sure not to put it anywhere near a heat or A/C vent, which will blast it with dry air.
Anthurium clarinervium likes both a warm and a cool period during the year.
In spring and summer, target an ambient temperature range of 65 to 73 degrees F (18 degrees C to 23 degrees C). Short periods of heat up to 85 degrees F (29 degrees C) are acceptable.
In fall and winter, you can let the temperature drop a bit, but make sure it doesn’t go lower than 54 degrees F (12 degrees C).
Re-pot your Anthurium clarinervium each year in spring, sizing it up to a slightly larger pot until it reaches its peak size of two feet tall by three wide.
After that you can simply do light root pruning each spring, refresh the potting soil, and return it to its same pot.
To re-pot this plant without damaging it, follow these steps:
- Water the plant a few days before and then just before you re-pot it. This will loosen the soil in the pot and lubricate it for removal.
- Sanitize all of your tools, and wash your hands well.
- Give the pot several firm taps on all sides; this will help the soil to break away from the sides of the pot.
- Lay the pot on its side, or tilt it slightly downwards into your waiting hand. Use a pencil to poke the bottom through the drainage holes, and wiggle out the root ball using your fingers or a plastic knife around the side of the pot. Don’t pull on the plant, and be careful not to bend or crunch any of its stiff leaves.
- Check out your roots. Prune off any dead, dying, or overly aggressive roots using a pair of sanitized scissors or garden shears. Be careful not to remove more than 25% percent of the root mass during this pruning.
- Place new potting soil or orchid bark at the bottom of the pot, enough to position the top of the root ball within 1 to 2 inches of the pot’s rim. Add soil to the sides, using your fingers or a pencil to help push it down.
- Give the pot a few good taps against your work surface to help the soil or bark settle.
- Wait to give your Anthurium clarinervium water for a few days. The dryness will let the pruned roots close off their cuts, and activate the other roots to begin spreading out and seeking moisture.
Leaf Discoloration Problems
Leaf discoloration in Anthurium clarinervium is usually the result of inadequate water or humidity, or too much fertilizer.
If the humidity is too low, the plant will develop brown, crunchy leaf edges. And if you overwater it, the leaves will turn yellow and limp.
To address humidity, place a jar of water right beside the plant or install a pebble try as an emergency measure, and consider getting a plant humidifier to remove the guesswork.
For overwatering, simply allow the plant to dry out thoroughly, down to the top two to three inches of soil, before you water again.
Use less water and give the plant water less frequently, and check that the drainage holes of the pot are free of clogs.
Too much fertilizer will cause some leaves to go yellow with brown tips. Flush the pot with several rounds of distilled water, and wait another four weeks to feed with fertilizer diluted to half-strength.
As a side effect of the high humidity that Anthurium clarinervium requires, they are susceptible to bacteria and fungal diseases, the most common of which is fungal leaf spot.
You’ll see discolored spots on the leaves, like this:
Treat fungal growth by removing any affected leaves and treating the rest with neem oil, an organic anti-fungal.
Then make some adjustments to your humidifying scheme, like moving the plant a farther away from the humidifier, or swapping it out for a damp-pebble tray.
The University of Florida has a helpful reference sheet for other Anthurium plant diseases, with detailed descriptions and treatment options.
However, most of these diseases tend to occur in commercial growing settings, and you likely won’t see them in your houseplant.
All these insects are sap suckers, which means that they use their mouthparts to pierce the plant’s outer layers and suck out its juices–sort of like plant vampires.
Afflicted plants will have yellowed or rumpled leaves, and their “honeydew” secretions will make stems and nearby surfaces sticky.
Inspect your velvet cardboard plant regularly.
Aphids are small, squishy, green, winged insects. Mealybugs have waxy white bodies and leave cottony deposits.
Scale insects don’t look like insects at all. They resemble little brown bumps or growths on the plant, but this is really just the outer shell that hides a tiny plant vampire within.
You can scrape them off with a finger or butter knife, then treat with an insecticidal soap or horticultural oil.
You’ll need to spray more than once to totally eliminate the aphids, mealybugs, or scale, so check back on the plant regularly.
Note: When checking your Anthurium clarinervium for these pests, make sure to look closely at the central growing point, the undersides of leaves, and any nooks or crannies.
And if you do find one or more of these insects on your plant, make sure to isolate it from other houseplants in your collection until the infestation is under control.
How to Propagate Anthurium Clarinervium
You can propagate your velvet cardboard plant with stem cuttings placed in soil (see the detailed breakdown in our Philodendron Splendid post), or by root division, which we’ll go over here.
These plants grow from crowns, and over time the main plant will produce secondary crowns, like a calving iceberg.
When your Anthurium clarinervium produces a crown that is at least an inch away from the main one, gently pull or cut it away (remove the root ball from the pot for this process if you need to).
Place the crown in a smaller pot but with all the same conditions for light, humidity, etc. You can also pop it into a glass of water until it has grown a few new roots, and then pot it up.
Within a year the new crown will be firmly rooted and sending out new leaves.
Frequently Asked Questions about Anthurium Clarinervium
With its unusual leaf texture and wonderfully compact habit, the Anthurium clarinervium makes a unique, striking addition to your houseplant collection.
Even though this plant does have specific needs for sunlight, moisture and soil composition, once you hit the right balance, you can enjoy your Anthurium clarinervium for years to come!
Do you have any experience caring for an Anthurium clarinervium, or do you dream of one day owning one?
Let us know in the comments!