Diario de sedgequeen

My colleagues and I are trying to figure out which bamboo species are growing wild or quasi-wild in Oregon and Washington, and to map where they grow. Would you please help us by posting appropriate bamboo sightings in these two states?

We are most interested in wild bamboo that are spreading down waterways or were plants spread accidentally by human activities (earth moving, dumping yard waste). We also want to know about quasi-wild bamboo forming long-abandoned stands that have spread within their site (e.g. in abandoned home sites). We have some interest in plants that have spread from cultivation less extensively (e.g. into an adjacent road ditch or under a sidewalk), but we are not interested in clones that have spread a little in a garden or into adjacent property.

What to photo? (1) The whole plant. (2) The main stems, showing stem color, persisting leaf sheaths (if present), tops of those leaf sheaths, and color or structures at nodes. (Node = the thickened ring where leaves or branches originate.) A photo with your hand or some other standard can help tell how wide the main stems are. In one species here, the lowest few stem internodes (places between nodes) are very short, much shorter than most internodes; photo that if you notice it. (3) The number of branches that grow from one node on the main stem. (4) Leaf shape. (5) The bases of leaf blades, where there may be conspicuous hairs. Their presence or absence can be a useful clue for identification. (6) The rhizomes (horizontal stems) if visible, but no need to dig for them. (7) If you find new shoots growing up this year, photo the sheaths and those projections, vestigial leaf blades, that grow at the sheath tip.

Comments can help. Estimate plant height, if possible. (Or show a person standing near the bamboo, for scale.) Bamboo stems may be absolutely smooth, as if enameled, or may be minutely scabrous (rough). If rough, they may feel rough when running your hand up or down the stem or only one way. Please describe. Are the leaves green or glaucous (blue-green or gray-green) on the upper and/or lower surface?

Some wild stands have Bamboo Mites, genus Stigmaeopsis, (e.g. https://www.inaturalist.org/observations/152900504 ). These don't matter to our project, but they can give you a second observation at the site, if you want. Be careful not to spread the mites to cultivated bamboo stands.

So far, we have found five wild and quasi-wild bamboo in Oregon and Washington. They are Arrow Bamboo (Pseudosasa japonica), Broad-leaf Bamboo (Sasa palmata), and members of the genus Phyllostachys. Obviously, we will be very interested to see observations of additional species in our area.

Phyllostachys species have a groove or flat surface extending up the stem from one node to the next. The leaf sheaths low on the stems fall of early. They typically have 2 branches per node on the main stem. Pseudosasa japonica and Sasa palmata lack that groove and have persistent leaf sheaths. I think both have just one branch per node; I'm sure Ps. japonica does. Pseudosasa is a taller, sturdier species with small, narrow leaves (to 2 inches, 5 cm, wide). Sasa palmata is shorter and more slender and has broader leaves (to 3.5 inches, 9 cm, wide).

Although the name Common Bamboo (Bambusa vulgaris) is commonly applied to Oregon and Washington observations, it is not common and probably not escaping (if present) in these states.

Note: We're at the very beginning of the learning curve for bamboo identification. We're improving, but so far we have just enough knowledge to be dangerous, so take any ID's we make with a grain of salt.

[Edited April 16. We are learning.]