In this in-depth look at the important houseplant, Philodendron, we started in an earlier blog post by learning more about their amazing biology – where they come from, and where and how they grow in their natural home. In another blog post you can learn the ins and outs of growing them to perfection – it isn’t difficult, but there are some ‘secrets’. Then we looked at the enormous range of species available, and which ones make the best houseplants. In this final post about Philodendron, we will look at hybrids – how they come about, and which are the best and most interesting.
Variation in the Appearance of Philodendron
There are about 400 species of Philodendron growing wild in South America and the Caribbean. At least, that is the most recent accepted number. It could be that there are many more – or there could be many fewer. We really don’t know. As well, there are many different varieties being grown in greenhouses, tropical gardens and as houseplants. Sometimes those plants are given species names, and then later it is realized they are not species at all. Why is there this confusion?
If you have learned much about garden trees, for example, you will know that you can usually identify a tree very accurately from the shape and features of a leaf. A tree may have millions of leaves, but each species has all the leaves the same. This makes giving them names – and them keeping those names – relatively simple. When botanists and horticulturists who learned their skills in cooler regions turned to tropical plants, they expected things to be similar – but they weren’t.
As we found in the first blog, Philodendrons have unusual life-styles, because they grow in different places in the jungle at different points in their lives. Some begin life germinating from a seed on the dark forest floor. Then they grow across the floor to a tree, climb it, and only when reaching the sunlight at the top do they mature and flower. Others begin as a seed germinating high in a tree, among leaves and debris. They grow as epiphytes, eventually sending long roots down to the forest floor for nutrients.
The result of this varied lifestyle is variation in leaves, with juvenile leaves being a certain size, shape and coloring, while adults leaves – those produced usually in bright light when the plant is ready to flower – being very different. Adult leaves are often much bigger, darker green, and may be shaped very differently too. Often the leaves can have many intermediate shapes too, as well as being influenced by light levels, temperature and nutrition.
How These Variations Affects Naming Plants
When collecting plants in these jungles, seeing just a few unique leaves, it is very easy for that plant to be given a name. You can immediately see how easy it is for one plant to end up with multiple names, as if it were two or even several species. For a unique name to be given to it, a botanist should have not just leaves, but also flowers and fruits – only then can he or she be sure it isn’t a plant that already exists. It’s a great concept, but often, in the real world, a few leaves get named by an enthusiastic botanist as a new species.
In their enthusiasm to grow new plants, growers and gardeners then propagate this plant, and start selling it with the name given. Meanwhile back among the botanists, these mistakes eventually get sorted out, although it can take a hundred years. By then the ‘wrong’ name is well-accepted among growers, and the last thing they want to do is confuse their customers by changing names. As we saw when talking about species, this means a lot of plants are sold with old, incorrect names, and it takes a push to get people to change.
A hybrid plant is the result of crossing together two different species, collecting seeds and growing the plants to ‘see what you got’. This is the way many of our garden and indoor plants got started. There are lots of Philodendrons we grow that are hybrids, although often we might not know exactly what the parent species were. Here is a list, with brief descriptions, of most of the different hybrid Philodendrons that are available.
‘Birkin’ – this superb plant has large, rounded leaves that are beautifully striped with thin white lines, some solid and some dotted. The effect is almost like a green pin-stripe suit .
Each leaf is outlined with a white line, and the leaf stalks are white too. In time it will grow larger leaves, and after years as a compact plant, will begin to grow up a moss pole. It is believed to be a ‘branch sport’ (a different-looking branch) of the hybrid variety ‘Red Congo’.
‘Bloody Mary’ – We don’t know the origin of this hybrid, but it is one of the best of the red-leaf plants with smaller leaves. It is distinctly climbing, needing a pole of stake, and has red stems. The leaves have long leaf-stalks and the leaves are spear-shaped, and bright red. Older leaves become dark green. The best leaf color will come in stronger light, but avoid direct sun.
‘Burle Marx’ – this plant is named after the famous Brazilian landscape architect of last century, Roberto Burle Marx. It has red stems and spear-head leaves of dark green. The leaves can become very large in suitable conditions. There is also a variegated form of this plant, with light green leaves irregularly splashed with light yellow.
‘Florida’ – this is a hybrid plant of the Oak-leaf Philodendron, P. pedatum, which we met in the post of species. The other parent is P. squamiferum, a plant with more rounded leaves. The result is a plant more vigorous and easier to grow than the Oak-leaf species. The leaves are divided into deep lobes, making a striking specimen. This hybrid dates back to the 1950s, made at Bamboo Nursery in Florida the botanist Robert McColley.
‘Florida Ghost’ – when ‘Florida’ produced a variegated stem-sport, the variegation showed as very pale, near-white new leaves. No wonder it is called a ghost. Slower-growing and a little more difficult, it’s unique and striking. Older leaves become more green. ‘Florida Beauty’ and ‘Glad Hands’, are other variegated varieties that have come from ‘Florida’.
‘Green Congo’ – when you want a big, bold specimen philodendron, turn to this vigorous and tough variety. It can stand 4 feet tall, with large leaves, without staking. The leaves are broad, pointed ovals, poised nicely on long stalks, and they are glossy and rich green – the epitome of a great houseplant. Generally trouble-free and easy to grow. The variety ‘Imperial Green’ is similar, but generally smaller, both in the leaves and the likely size.
‘Rojo Congo’ – also called ‘Red Congo’, this is a large, upright plant that grows vigorously with deep red stems and red-green leaves. Low-light will make the leaves greener, so find a bright spot out of direct sun.
‘Moonlight’ – chartreuse is a super-fashionable garden color, and available in lots of garden plants. It’s much rarer among houseplants, but this philodendron has amazing chartreuse yellow new leaves, maturing to bright emerald green. Easier to grow than variegated varieties, it’s a way to really make your collection shine. The leaves are large, and the plant resembles a rubber tree at first glance, but with more pointed leaves.
‘Prince of Orange’ – another superb plant with bold leaf colors, this bright plant has new leaves of light yellow-orange, darkening to a burnt orange. They mature to
‘White Knight’ – this is a highly-variable variegated plant, with almost pure white areas on dark green leaves. ‘White Princess’ and ‘White Wizard’ are very similar, and it is possible they are the same, and any apparent differences are due to growing conditions and age.
’Black Cardinal’ – if you like red, then you will love this one. The big leaves are bright, dark red when they unfurl, turning darker as they develop and then turning dark green with age. Big, self-heading until old, so ideal for specimens.