It begins with the realization that “lucky bamboo” is not actually bamboo at all. And then they tell you there are two kinds of bamboo: runners and clumpers. But then you discover that there are more than 1,400 species of bamboo, plus a few hundred cultivars and subspecies, bringing the total number of distinct varieties closer to 2,000. And now you want to know how to tell them all apart.
Identifying different species of bamboo can be very difficult. The best technique is to spend a lot of time among the bamboo and get to know as many varieties as possible. The most helpful indicating factors include the size and shape of the culms, the size and shape of the leaves, and the branching pattern. Experts will pay close attention to smaller details in the fresh shoots, the culm sheaths and the internodal joints.
The following article should serve as something of an introductory lesson in identifying bamboo species, filled with lots of photographs for reference. To become a real expert in recognizing bamboo, a person could spend a lifetime studying the leaves and branches of these remarkable grasses. But this will give beginner and intermediate gardeners a reasonable orientation and a place to get started.
Identifying running bamboo
It’s true that we can divide the many species of bamboo into runners and clumpers, although it’s not always a perfectly clear distinction. Botanically speaking, bamboo has two types of rhizome systems, either pachymorph (clumping) or leptomorph (running). But some running types actually run pretty slowly. And some clumping bamboo has a tendency to spread out; we call those open clumpers.
The genus Phyllostachys is made up of super vibrant, running bamboos. They are some of the most vigorous and fast-spreading of all bamboos. And this can be a point of concern for many growers.
The good news is that, as a genus, Phyllostachys are some of the easiest to recognize. Look for the shallow groove that runs lengthwise on alternating sides of the culms (stems), in between the joints. These are called sulcus grooves, and they’re a sure marker of a running Phyllostachys. Another way to recognize these bamboos is by counting the branches at each node. Phyllostachys generally have two branches at the node, roughly the same size.
Black bamboo is probably the easiest of these to recognize, because of its eponymous color. As seen in the photo above, there are two branches, equal in size, growing out at the node. Just above the node, on the same side, you can see a narrow groove running lengthwise, upwards.
There are several timber species of Phyllostachys, and they can be very hard to tell apart. Even the experts will argue whether its a P. bambusoides, P. vivax, P. edulis or P. nigra ‘Henon’. Vivax is typically the largest species, sometimes more the 5 inches in girth. But each species performs differently in different soils and climates.
Henon is a subspecies of Black Bamboo, but with greyish-green culms. It also goes by the common name Giant Gray Bamboo.
Some of the most interesting Phyllostachys are the striped cultivars, shown at the top of the article, in the featured image. P. aureosulcata ‘Spectabilis’ and P. aura ‘Aureocaulis’ are especially eye-catching. The striping is similar, but ‘Spectabilis’ sometimes grows with an exotic zigzag.
Sorting Pseudosasa and Semiarundinaria
If the bamboo culms don’t have the sulcus groove, then it’s probably not a Phyllostachys. (Although sometimes the groove is too subtle to detect). But it could still be a runner. Other ornamental running bamboos include Pseudosasa and Semiarundinaria. These are medium-sized, upright bamboos, with many popular species for gardens. S. fastuosa, or Temple Bamboo, is one of the more popular species of Semiarundinaria. The mature culms often take on a burgundy hue, especially in shady spots and during the cooler months.
Pseudosasa is generally somewhat shorter, with thicker, greener foliage, while leaves of Semiarundinaria grow more in tufts, and have a lighter green color. P. japonica, or Arrow Bamboo, is the most popular species of Pseudosasa. P. amabilis, or Tonkin Bamboo, is also fairly common. The culm sheaths are late to fall on both of these species, but the sheaths on P. amabilis are harrier.
Distinguishing dwarf bamboo
Most species of dwarf bamboo are also runners. Despite their short stature, their roots can be very quick to spread. The most common genera of dwarf bamboos are Sasa and Pleioblastus. The most popular varieties have striped leaves, either green and white or green and yellow. Sasa leaves are usually wider and shorter.
Check your Chimonobambusa
A fairly exotic genus of bamboo, but Chimonobambusa is worth looking out for. And with their strikingly unusual culms, they are pretty easy to recognize.
C. tumidinoda, or tumidissinoda, is nearly unmistakable with its bulging joints. The name tumidissinoda actually means “tumescent (or swollen) nodes”. C. quadrangulus, or Square Bamboo, is another one to watch for. As you might guess, its slender culms are almost square in shape.
Classifying clumping bamboo
If you poke around at the base of a mature bamboo plant, or examine the distribution of fresh shoots, you can usually tell if it’s a runner or a clumper. Clumping bamboos don’t have those long, creeping rhizomes. The plants tend to stay in a tight cluster with a limited footprint.
Also, most clumping bamboo is tropical or subtropical, so you rarely find it growing in colder climates with frost and snow. Unless it’s a Fargesia, which is among the most cold hardy of all bamboo.
A bevy of Bambusa
Bambusa is one of the most widespread genera of bamboo, with about 150 species. They come in a range of shapes and sizes, but mostly they’re buttery yellow and pretty big around. Some are striped, similar to certain a species of Phyllostachys (see above). But the arrangement of branches will quickly set them apart.
Hip to Himalayacalamus
The genus Himalayacalamus is exotic but very popular among collectors. Native to the lower elevations of the Himalayas, these bamboos prefer cooler, shadier settings. They are somewhat cold hardy, and the clumping roots make them desirable among gardeners. Their coloration is the easiest way to identify them.
Himalayan Blue, pictured above, is very similar to Nepalese Blue (Himalayacalamus porcatus), except that the former is about twice as tall. H. hookeranius typically grows 15-20 feet tall, while H. porcatus usually only gets 5 or 10 feet tall. In both cases, the culms are normally 1-1.5 inches thick, and the leaves are notably slender and delicate, adding to their graceful appearance.
Drepanostachyum is closely related and often mistaken with Himalayacalamus. The main difference is in the branching structure. Drepanostachyum culms have many equally sized branches at each node, whereas Himalayacalamus will have one dominant branch.
If you have a clumping bamboo that survives in the snow, you can be pretty sure it’s a Fargesia. Especially popular in Europe, Canada and northern swaths of the US, it is also recognizable for its long leaves and drooping culms.
F. murielae is considered one of the most attractive species of this genus. F. nitida is also very noteworthy for its colorful culms which earned it the nickname Blue Fountain Bamboo. Another colorful variety, F. scabrida has shoots that come in shades of orange, blue and purple, eventually turning deep green. But the blues and hues on these bamboo won’t be as bright and vibrant as those Himalayan varieties above.
Tropical timber bamboo
The most impressive of all bamboos, at least in terms of size, are the tropical clumpers. Genera like Dendrocalamus and Gigantochloa have some truly fabulous specimens. As tropical species, don’t expect to find many growing north of Florida or Southern California.
Dendroclamus includes the largest species of all bamboo. Although they are technically clumpers, their pachymorph rhizomes often stretch out several feet from the main plant. The ariel roots that sprout in rings around the lower nodal joints are a distinguishing feature.
If you come across a giant timber bamboo in South or Central America, you can be almost certain it’s a Guadua, native to the highlands of Colombia. These formidable bamboos are very important in that part of the world, but they need to be close to the equator and don’t really grow in North America.
Elsewhere in Latin America, if you come across a medium-sized stalk of bamboo, you can try sawing it in half. If it’s solid in the middle, rather than hollow, then you can bet it belongs to the genus Chusquea. These temperate clumpers actually grow quite well in North America, and the solid poles are great for building and crafts.
Expert opinions in bamboo identification
Because identifying bamboo species can be such a challenge, you may prefer to consult an expert. The best way to go about this is by providing a good assortment of photos.
Take one picture that captures the whole shape of the plant. This will show the overall growth habit, the general arrangement of the leaves, and whether the culms are fully upright or arching. Also take a close-up picture of the nodal joints, so you can see how many branches are coming off, and examine their relative sizes. A photo of the base of the plant, where the culms emerge from the soil is also helpful, especially if there are fresh, young shoots still developing. Finally, a close up shot of some leaves can be useful, showing the arrangement of the leaves and their position along the stems.
In many cases, if the photos are clear and well-focussed, this will be enough for a bamboo expert to identify the species. But they might only be able to narrow it down to two or three members of a certain genus. Sometimes it’s necessary to observe some minute features over the course of a growing season. Anyway, you’ll know enough to know what sort of sun, water and soil requirements your bamboo has. Beyond that, it’s all just sort of academic anyway. So good luck, and happy growing!
If you enjoyed learning a little bit about bamboo species identification, you won’t want to miss these other in-depth articles about the wondrous diversity of bamboo.