We often hear about hoyas, which are attractive indoor plants that sometimes flower and are easy to grow. In fact, we talk about them so much that we sometimes forget to mention their cousin, or rather their sister, the dischidia, which is almost as easy to grow. So today we’re shining the spotlight on this little-known indoor plant.
Origin
Dischidias are found in the wild in Southeast Asia, in tropical regions, and some species are also found in Oceania. This small plant, belonging to the Apocynaceae family, remains relatively unknown and has been little studied. Of the Apocynaceae family, hoyas are commonly grown indoors, as are oleanders (Nerium oleander).
Description
I began this article with a comparison to hoyas because dischidias are very similar to them in several ways. Epiphytic in nature (meaning that the plant grows on the bark of another tree or in the hollow of a branch, without parasitizing its host), dischidia can be climbing or trailing. The leaves are succulent, oval or heart-shaped and opposite on the stems.
Unlike hoya flowers, the white, cream, or pink flowers of dischidia grow in the leaf axils and are small in size: they are generally described as rather insignificant.
However, where dischidias differ positively from hoyas is in the asymmetry of some of their leaves: in several species, a much larger, hollow leaf grows from time to time, whose function in nature is to form a kind of pocket where ants can take refuge. In exchange, the ants defend the plant against parasites, clean it, and feed it with their excrement. These dischidias are said to be myrmecophytic, meaning they have a symbiotic, mutually beneficial relationship with ants (which, for indoor plant cultivation, is a fascinating topic of discussion with guests, but has relatively little practical use. I don’t know about you, but I personally don’t have much desire to have a myrmecophilic relationship with ants in my living room!).
Varieties
The main varieties that are myrmecophytes are D. major, D. vidalii, D. platyphylla, D. complex, D. imbricata, and D. astephana. They all tend to form the larger leaves mentioned above, except for D. complex, whose leaves grow normally if they are drooping and stuck to the bark of a tree and if they have support. At this point, the leaves of D. complex become domed and serve as shelters for ants. The same is true for D. imbricata, which, as its name suggests, grows interlocked on the bark of a tree. As for D. platyphylla, it does not bother with such details and can form both suspended inflated shelters and domed shelters attached to the support. Finally, the roots of D. astephana grow inside anthills, where they have unrestricted access to nutrients.
That being said, it is quite rare to find these unusual plants in garden centers, especially in Canada. D. vidalii is sometimes seen, with its slightly pointed leaves and pink flower buds (which never open). It is also found under the name D. pectinoides, and to date, botanists have not yet determined which name to use. It is easy to grow. You can also look for D. major, but it is more delicate than the previous variety. Its leaves are longer and thicker.
D. ruscifolia
There are other dischidias that can be found from time to time; however, the plants shown above are prized for their aesthetic qualities alone, as they are not myrmecophytes. My favorite is D. ruscifolia, also known as “Million Hearts” or “String of Hearts.” The heart-shaped flowers grow densely on the very short petioles of this miniature plant. It is seen entirely in bright green or variegated with white.
D. oinantha is an easy-to-grow variety with oval leaves. It is often found in variegated forms, with whitish-green leaves edged with white, creating a luminous effect. The same is true of D. nummularia, with its smaller leaves and dense habit, which comes in green or variegated white forms. One cultivar is particularly worth mentioning: in good light, the almost round leaves of D. nummularia ‘Dragon Jade’ grow so densely that they completely cover the stem.
Even rarer, you can look for D. ovata, whose small pointed leaves are lined with white veins that are somewhat reminiscent of watermelon skin, or D. hirsuta, whose textured leaves are sometimes covered with small hairs (in fact, the appearance of this plant is described as highly variable depending on growing conditions, so the hairs are not guaranteed despite the name).Finally, an honorable mention goes to D. albida, which was praised by Laidback Gardener in 2017.
Growing Tips
Light
While hoyas tolerate low light well, this is not entirely true for dischidias. Ideally, the plant should grow in bright light with a little direct sun in the morning or late afternoon. It can be taken outside in summer and will thrive. However, it may become spindly in medium light conditions.
Watering
This strictly succulent plant requires the soil to dry out before watering. Except for small-leaved varieties (especially my beloved D. ruscifolia), you can even wait until the leaves wrinkle a little before watering. All dischidias are very prone to soil rot.
A plant that grows densely in a small pot may benefit from being watered by pouring water over the pot.
Atmospheric Humidity
Unlike other succulents, dischidias grow much better in high humidity—they are, after all, tropical in origin. The more delicate varieties (D. major, D. ruscifolia, D. hirsuta) can suffer from a lack of humidity, especially in winter. That said, these plants are still very easy to grow and do not complain too much about dry air.
Soil and Potting
A well-drained soil is absolutely necessary for growing these epiphytic plants. Orchid mixes are very suitable, or any potting soil mixed with perlite, vermiculite, or bark pieces.
Fertilizer
Dischidias can be fertilized in the soil or directly on the foliage, much like orchids. It is unclear whether these plants are heavy feeders: epiphytes generally require little fertilization, so half the recommended dose would be sufficient, but the fact that myrmecophytic plants produce leaves to attract ants suggests that they appreciate regular fertilization. In any case, only plants that are actively growing should be fertilized.
Temperature
Warm temperatures of at least 15°C (59°F) are necessary to remind it of its tropical origins.
Care
Dischidias require little attention. The leaves are very tenacious on the stem and can make a well-stocked pot for those who have the patience to let them grow at their own pace. You can shorten stems that are too long and encourage the plant to develop branches for a denser habit. Caution: cut stems produce a copious amount of milky sap that can be irritating. Rinsing the wound with cold water will reduce the flow.
Plants growing against a wall may try to adhere to it with their adventitious roots. This is a problem especially in high humidity conditions, such as with a constant humidifier or outdoors. Dischidias can be difficult to remove and may leave a mark on their support.
Variegated plants require more specific care: simply remove the entirely green stems, which are more vigorous and may end up dominating the plant. This is only necessary if you want to keep a completely variegated plant (personally, I like to take cuttings from the green plants and keep them in a separate pot from the variegated plant). The other downside to this maintenance is that you have to remove the completely white stems, which cannot photosynthesize and therefore become parasitic on their host.
Propagation
Dischidias are easily propagated by stem cuttings. Cuttings can be taken in water or in potting soil, which is generally the recommended technique. For cuttings in soil, it is necessary to keep the soil slightly moist, but above all to maintain high ambient humidity by covering the cuttings with a transparent plastic bag.
Problems
- Few problems affect well-treated dischidias.
- Overwatered plants tend to rot quickly. Moderation is key!
- Stressed plants may lose their new leaves, especially when watering is too infrequent or ambient humidity is very low. Apart from this loss, they recover well from these deviations, provided that the growing conditions are corrected.
- Dischidias may be attacked by generalist insect pests such as scale insects and thrips, but they do not seem to be their favorite food.
Toxicity
Apart from their sometimes irritating sap, dischidias are not toxic. At most, some species may cause brief gastrointestinal discomfort.
Presentation Tips
Dischidias can climb along a piece of bark, especially in very humid conditions, but are more often found hanging. They make good plants for kokedama.
Conclusion
If this article has inspired you to grow this easy plant, I wish you the best of luck in finding one at a garden center. Once you find it, if you don’t water it too much, you’ll probably be able to grow it for many years to come without repotting it once. Long live dischidias for laidback gardeners!
An interesting and well written article. This looks like a lovely plant to add to my indoor collection. I have seen this plant for sale at one or our garden centers. It’s always attached to and growing up a slab of bark. Thanks for the information.