Written by davethetreecenters • May 30 Get To Know Philodendrons

In the world of houseplants, Philodendrons are big. Not just in size, although many are, but in popularity. No wonder – these plants are mostly easy to grow, and come in a wide variety, often featuring big, glossy leaves in exciting colors. They are the essence of a houseplant – a reminder of more exotic places, and plants that let you bring the jungle right into your home. Let’s explore this exciting group of plants and learn more about them. In our next post we will find out how to grow them really well. Then, in this blog post we look at some of the amazing diversity of these plants available for you to grow at home.

You can tell people have always loved Philodendrons – even the name says so. Dendron is Greek for a tree, while Philos is love, so these are literally, ‘loved trees’. An alternative idea is that the heart-shaped leaves of many of them is the reason for the name. This seems unlikely, because then they probably would have been called Cardiodendron!

Meet Philodendrons

Philodendron is a very large genus of plants, with almost 500 species, and likely many more still not discovered or named. It is part of a larger family called Araceae, the arum family. Often called Aroids, these plants are recognized by their similar-looking flowers, that resemble the well-known Peace Lily, as you can see here. There are lots of houseplants that are Aroids, such as Monstera and Aglaonema, as well as Anthuriums, Pothos, and Dieffenbachia, but none of those plants should be called Philodendrons.

A. Lysichiton americanus B. Symplocarpus foetidus C. Anthurium faustomirandae D. Spathiphyllum friedrichsthalii E. Monstera tuberculata F. Anaphyllopsis americana G. Anaphyllopsis americana H. Calla palustris (someone is sure to ask for the names!)

Do Philodendron Plants Flower?

Yes, they do, as you can see here. When grown as houseplants, though, many Philodendrons only flower when large, or after you have been growing them for several years. If they do, take it as a compliment, you must be doing a good job growing them. These plants rely on beetles for pollination, not bees or butterflies. Usually each species has its own species of beetle pollinator, so if you want to produce seeds on your own plants, you need to hand-pollinate them. The beetles use the inside of the flowers as a safe place to breed, and the flower actually heats up to attract them, and make them more active so they move around more and pick up more pollen. Once the flowers are pollinated they develop a cluster of berries, which can be red or yellow, with seeds inside. These are often attractive, as in the hardy outdoor Aroid, Arum italicum.

Where Do Philodendrons Come From?

Philodendrons all originated in South America and the Caribbean. They live in humid tropical jungles, along river banks, and sometimes on rocky outcrops. When in the jungle, these plants really stand out, and apart from the trees they are often the most common things growing. The life of a philodendron starts out in one of two different ways. Some begin life as epiphytes, germinating in the debris high in trees. They don’t get many nutrients, but they do get plenty of light. As they grow they send out long roots, which eventually reach the ground, where they can get more nutrients, and grow faster and bigger.

A few, though, take the opposite approach. The germinate on the ground, and grow across the ground until they meet a tree trunk. Then they climb up it towards the sun, using a tangle of roots to hold on. Once well-established in a tree they may give up their connection with the ground, and live as epiphytes. Notice that these plants are not parasites – they take nothing from the tree that supports them, they just climb it to reach the light.

Philodendrons that start on the ground often have different kinds of leaves. Leaves in the shade are often smaller and rounder. Once they have more light they become larger, often a different shape, and sometimes divided into lobes. These differences have caused problems, with the juvenile stage of the plant and the adult stage being given two different names, as if they were different species.

Different Kinds of Philodendrons

From the point of view of growing them at home, there are two different kinds of Philodendrons. Some are called self-heading, arborescent, or simply non-climbing types. These produce a short, upright stem that is strong enough to hold the leaves up. They don’t trail or really climb, and these kinds are great for table decoration, especially on lower side-tables, or on low shelves. When they grow larger they can also be used as floor plants.

Although shown here as two different species, P. bipannitifidum and P. selloum are just leaf variants of the same plant, now called Thaumatophyllum bipinnatifidum

The second kind are called vining or climbing types, and these include the well-known heartleaf philodendron, or sweetheart plant. That plant can be grown as a trailing, basket plant, or as an upright plant, with support. These have stems that are weaker, and cannot hold the leaves upright. Larger climbing varieties need support, climbing up sticks, ropes and moss poles. These produce many thick roots to hold on with. These make terrific floor plants and big plants to put into a corner.

Some arborescent Philodendrons become climbing when they are large and old, while some climbing types are sold as self-heading when young, taking a few years before they start to climb.

Are Philodendrons Poisonous?

These plants all contain the chemical calcium oxalate in the form of crystals called raphides. These are potentially poisonous, but almost never cause more than the mildest symptoms in humans. Even babies have eaten pieces of the leaf with no serious harm. One case of a child death has been reported, but in a study of 127 children, they had no significant symptoms, except for one that had a swollen lip.

The same is true with cats. Although there are stories of cats dying from eating Philodendrons, in actual tests where cats were fed a puree of the leaves and water, up to high doses, they showed no symptoms. It could be that a sick cat tries to eat the plant – as they do grass – and then it has been assumed that is was the leaf making them sick. Studies have shown, though, that mice and rats can be killed from eating the leaves.

The lesson seems to be to be cautious, and stop a pet – or child – from eating the leaves, but the risk seems to be extremely small.