New boos on the block

Time for a new plant parade! I acquired quite a few new bamboo species in trade last week and am so excited, it motived me to finally write a post! I got these in trade with Ian Barclay at The Desert Northwest, in exchange for a couple pots of Dicksonia fibrosa I grew from spore and a division of my Borinda gaolinensis.

First up is a Chusquea culeou with stems that show more red than typical, or so I've been told. I trust the source. The red color will develop once it's in the ground and starts to mature. Chusquea are not fond of growing in containers and rarely look their best in them.

Some of the red color showing. It's primarily on new culms.

Foliage shot

Next up is another Chusquea. This one may be listed as either Chusquea culeou 'Argentina' or Chusquea argentina. I've read that it's been reinstated as a species in its own right, so I go with Chusquea argentina. It has longer branches than Chusquea culeou and, I'm told, an excellent winter appearance.

Foliage

Culms

This is a form of Fargesia robusta which is unfortunately going around under the name Fargesia robusta 'Robusta'. Besides breaking the rules of the International Code of Nomenclature for Cultivated Plants by being a Latinized cultivar name made after 1959 AND by being the same as the species name, it's impossible to research because you're just typing "robusta" into the search engine twice. 

Nomenclatural rant aside, this is possibly my favorite form of Fargesia robusta. The leaves are much larger than the more common 'Campbell' and 'Pingwu' forms, giving more lush, tropical appearance.

The leaves aren't quite as big as those on 'Wolong' or 'Wenchuan', but unlike those cultivars which arch rather strongly under the weight of their leaves, the one large specimen of 'Robusta' I've seen was staunchly upright, foliage fanning out in graceful layers. The culm and leaf sheaths are a nice rusty red which contrasts nicely with the green young culms. The culms age to yellow-green, even verging on pure yellow, and the leaf sheaths continue to provide contrast. (leaf sheaths are the parts that wrap around the branches, with the leaf blades, what most people think of as the entire leaf, attached to their ends)

Here we have Borinda contracta. From what little I can find on it, this seems to be one of the smaller Borinda species, only reaching about 15 feet (at least in the PNW). As I've run out of space in the garden proper, this one will be put to the test somewhere on the fringes, meaning it won't get as much water. This could be a big mistake on my part. Many Borinda have a tendency to shoot in fall when our rains return, and the tender young culms are then killed by frost. Thus far it hasn't been a problem with the species I have, 3 of which receive water in summer. I'll find a spot for this one that doesn't dry out too badly but doesn't get too soggy in winter, and see what it does. Sometimes you have to experiment and test limits.

The upper culms and branches take on a lovely purple color.

The leaves are soft and graceful.

The only running bamboo of the bunch, Qionzhuea tumidissinoda (aka Chimonobambusa tumidissinoda) will be staying in a pot for the foreseeable future. It has a reputation for being a particularly vigorous runner, though supposedly it can be kept in check if given a good spot surrounded by harsh conditions. There are always trenches and barriers, too. 

This small plant does not yet show the grace of a mature specimen, with airy layers of delicate foliage that could put a Japanese maple to shame.

The main draw of this species, however, is the unique culms. The nodes can be up to twice the diameter of the internodes. The trait isn't strong on young plants like this one, but you can see the slightly swollen nodes in the photo below. This species is traditionally used to make walking sticks and canes.

This fine-foliaged bamboo is Thamnocalamus crassinodus 'Mendocino'. This is another plant with not much information available. Some cultivars of this species are rather tender, hardy to only 15-20F. 'Mendocino' is claimed to be hardy to 5-10F. The species is known to defoliate in especially cold winters, but typically leafs out fully the following spring with no other damage.

The fine foliage is apparently on the large side for this species.

Reaching a potential 18 feet tall, more upright than many temperate clumpers, with purple shoots that reveal blue young culms aging to yellow-green, supporting light, airy clouds of foliage, this is sure to be a remarkable specimen as it matures. The branches and upper culms typically take on more reddish color as they're exposed to the sun, and the darker nodes ringed in white add additional interest.

Finally, we have Yushania brevipaniculata 'Wolong'. This plant has surprised me. It's the most intriguing of the bunch for me and inspires my imagination the most. The tiny leaves on short branches remind me a little of the foxtail-like plumes of Asparagus densiflorus, except that this bamboo grows 6-8 feet tall.

Yushania is one of those odd genera that breaks the rules. Most bamboos can be easily classified as clumpers (pachymorph) or runners (leptomorph). While Yushania technically have pachymorph rhizomes, where a rhizome produces a "neck" from which another rhizome grows, terminating in an upright culm, Yushania produce two types. The upper part of the rhizome, closer to the culm, produces short necks with limited rhizome development from which new upright culms emerge. This is known as "tillering" and differs from normal pachymorph rhizomes. The fully-developed rhizomes on Yushania are born on necks that can be much longer than typical pachymorph bamboo. This gives Yushania a diffuse to aggressively spreading habit, though not as potentially aggressive as leptomorph bamboos like Phyllostachys or Sasa. They are, however, often treated as runners by nurseries, because they do have the capacity to spread faster than most clumping bamboos. This illustration provides a better explanation of the different types of rhizomes than I can provide.

Yushania also tend to grow deeper roots and rhizomes than most bamboos, making them more drought tolerant but also meaning you have to dig down a bit further to cut any rhizomes escaping their bounds.

The blue-green new culms with their speckled, purple sheaths are beautiful, even more contrasted against my dirty, dried out gardener hands.

The unique rhizome structure of Yushania make them excellent hedge bamboos for shade, being able to spread with more upright culms than most Fargesia, but without the extremely fast spread of other shade-tolerant spreaders like Sasa. With the exceptionally airy foliage of Y. brevipaniculata 'Wolong', I have a vision of this bamboo creating a small screen in one area and a feature in another bed. I expect it to be much denser once planted in the ground, so it will likely need thinning for the effect I'm picturing.