Howdy folks.

How do Phyl grow? In particular, what explains the grooves? I know that they are caused by leaf buds, but I don't understand how that works.

Also, what's the mechanism and/or cause of the crook stem for the Phy A varieties?

Cheers,

jp

A new shoot has a protective leaf sheath. This sheath is responsible for the grove between nodes and for the crooked stems that some species of Phyllostachys show.

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M

Thanks Moriphen.

How is the sheath responsible for the grooves and crook stems?

jp

From what I've seen, the groove on a Phyllostachys looks like it is caused by where the branches join the culm as it grows. But the culm sheath affects culm growth where it attaches to the culm. Where the attachment is weakest the culm growth is slowest. By creatively detaching the sheath one can do interesting things to the way the culm grows, like making Yellow Groove culms look like aurea culms.

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Southern Indiana. Theoretically the same climate as 'needmore' & 'Eastlandia'.
My Bamboo List.

"Take Dog apart. Disinfect. Reassemble."

I believe that the groove is caused by the dormant branch bud scraping against the internode when the shoot is elongating, you'll not have a groove below the first branch - for example some of mine may be branchless for 8-9 feet, then the first branches - there are no grooves on those lower portions. As the branches jump from side to side, so does the groove.

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Brad Salmon, zone 5b/6 Southern Indiana
Winters -20 to -25C. Summers 30 to 35C , humid. 115 cm annual precipitation, frost free from May through early October. 259.3 meters elevation. Growing 150+ species. http://www.needmorebamboo.com/

Brad,

Which dormant branch bud causes which groove? Do the shoots grow like a telescope?

jp

Yes, I believe like a telescope, exactly. The groove is always above the branch is it not?

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Brad Salmon, zone 5b/6 Southern Indiana
Winters -20 to -25C. Summers 30 to 35C , humid. 115 cm annual precipitation, frost free from May through early October. 259.3 meters elevation. Growing 150+ species. http://www.needmorebamboo.com/

Brad,

I thought it might be like a telescope, but if that's true I still don't understand why the thin part of the culm appears from the ground first. The thickest part doesn't appear until later. How does that work?

jp

Well, I think that the 'telescope' is 'shoved' down into the base which is attached to the rhizome via the 'neck' so the tip sticks out the top, the base remains where it is, the remainder of the shoot rises up out of it. Notice how once they are up a few inches the max diameter of the shoot/new culm is apparent and no part of it is ever wide that that base (has to be more than a few inches on rapidly tapering species like atrovaginata, parvifolia). Having typed that, I have noticed that members of the aureosulcata clan seem to have the widest part of the culm 'up culm' somewhat and not at the base???

Just my thinking on it, I'm open to a better explanation if there's one out there.

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Brad Salmon, zone 5b/6 Southern Indiana
Winters -20 to -25C. Summers 30 to 35C , humid. 115 cm annual precipitation, frost free from May through early October. 259.3 meters elevation. Growing 150+ species. http://www.needmorebamboo.com/

Telescopic growth past dormant leaf buds is the best explanation I can find for the grooves. Regarding the position of the fat part of the culm, I wonder if that has something to do with how the internode lengths develop. Once the shoot emerges, how long is it before all the nodes are visible above ground? Once they are all above ground, how much of the growth is lengthening of the nodes?

p

Slice a new shoot in half lengthwise, it may be revealing to you - you'll see a 'honeycomb' look as the shoot is already divided into internodes.

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Brad Salmon, zone 5b/6 Southern Indiana
Winters -20 to -25C. Summers 30 to 35C , humid. 115 cm annual precipitation, frost free from May through early October. 259.3 meters elevation. Growing 150+ species. http://www.needmorebamboo.com/

Yeah, I did that yesterday. You can already see the leaf buds, that's why telescopic growth makes sense.

But, if you split a non-phyllo shoot, can you see the leaf buds?

jp