What is this bamboo

[johno]

Can anyone ID this Bamboo. I think it is in the bambusa group. I planted it from a root cutting about 12 years ago. It's tallest culm was about 45 feet tall until the power company bobbed off the tops. The largest culm diameter is about 3.25 inches. It's largest leaves are about 1" by 7". It has multiple branches leaving the culm usually with one large one and 2 medium ones and then 7 or 8 small ones but this varies. It sends up new shoots in late summer through fall. The culms are thick but hollow. See the pictures of new culms and others.
Thanks,
Johno

[Mark Meckes]

Hi Johno,
It looks like Bambusa oldhamii (http://www.bamboocraft.net/bamboo/showgallery.php?cat=505) (pics at gallery Bamboo Flora)

Do the new shoot's culm sheaths sometimes have hairs on the surface as shown here?:
http://www.bamboocraft.net/bamboo/data/505/thumbs/B_oldhamii_ATX-040626-134.jpg (http://www.bamboocraft.net/bamboo/showphoto.php?photo=994)

Mark

[johno]

Thanks Mark,
I checked for hairs on the new culms as shown in your photo but found mine to be smooth and powdery. Some of the culm sheaths have a small amount of hair on the fringe only noticable with a magnifying glass. I rechecked a large leave and it measured 9" by 1.5". The leaves on my specimine apear to be slimmer than the leaves in your photos. All in all my bamboo looks very close to your photos of oldhami. Is there very much variance in different clones of the same species?
Thanks again
Johno

[Mark Meckes]

Hi Johno,
I'm always happy to culmcede that it is another species if it can be shown, but so far Bambusa oldhamii is the only species I can think of ...

Regarding hairs on the culm sheath, sometimes the lower sheaths don't have any hairs on the outer surface and are smooth, while sheaths further up the culm will have more hairs
If the pic of the new shoot is recent, check as it grows taller for any hairs on the sheath surface.

Another reason I've guessed it as B. oldhamii is the upright stature of the culms in the planting, which is typical of this bamboo.

The leaves you measured (9" by 1.5"), are a little smaller then my planting
(up to 12" X 2"), but leaf size also varies with climate and water availability, and I noticed that on one side of the planting there is a cactus growing very nicely, so the growing conditions must be fairly dry.

Is there very much variance in different clones of the same species?
Generally I'd say that differences in cultivars of the same species have more to do with their overall plant size, shape and culm and leaf characteristics.
Shoot/sheath traits are "usually" quite similar with different cultivars of the same species type ... though I could give examples where this is not the case. One example that come to mind with another genus is :
Phyllostachys nidularia and Phyllostachys nidularia 'Smoothsheath'

I don't know/haven't heard if there is a B. oldhamii cultivar similar to this.

In the US, the majority of bamboo species are clones which have been vegetatively propagated from the original introduced plant.
But this is gradually changing as some bamboo species come into flowering.
Many species produce few if any viable seed, but with species that do and are grown from seed, there's always the possibility that some seedlings may turn out different in shape and form etc.

Mark

[johno]

Well oldhami it is. I apreciate your expertice. I'll be watching for the hairy culms and sheath as it growns taller.
Thanks,
Johno