Bambusa oldhamii.
Family Poaceae > Subfamily Bambusoideae > Tribe Bambuseae.
Oldham’s Bamboo is a rapidly growing species from China.
Fairly dense clumps of culms grow from short underground rhizomes.
The light to dark green culms are erect with some arching slightly at the top.
They are up to 18 m high and 10 to 12 cm in diameter.
The hollow internodes are 20 to 30 cm long and the lower ones are not compressed.
They are round in cross section with no grooves or hairs.
They are initially covered in a white coating or bloom but this is gradually lost although
some may remain as a band below the nodes.
The nodes do not have aerial roots.
The persistent culm sheaths are up to 30 cm long with a broad triangular blade.
Young culm sheaths have long, fine partially flattened hairs but these fall off.
Rounded auricles are usually present but they may be very small and they are sometimes absent.
They have setae up to 3 mm long on the edge.
Several branches grow from each node except those on the lower few metres of the culms.
Branches are up to 1 m long and one is stouter than the others.
Each branch has up to 9 alternately arranged leaves.
The lanceolate to oblong blades are up to 25 or 30 cm long and 6 cm wide with a pointed tip.
The base narrows forming a short pseudopetiole.
There are initially some hairs on the lower surface and the edges are rough.
The ribbed leaf sheath is up to around 12 cm long.
The small auricles have thick 0.5 cm long setae.
At the junction of the leaf blade and sheath is a small membranous ligule.
The upper edge has no hairs but may be irregular (eroded).
There is also an external ligule.
Inflorescences, up to 1 m long and with basal bracts, grow from the nodes.
They have a number of flattened spikelets up to 4 cm long with basal glumes.
Each spikelet has up to 10 fertile florets and some sterile ones towards the tip.
The florets have a lemma with a mucro (short pointed tip).
The palea has hairs on the keel and there may be hairs on the surface.
Inside the lemma and palea are 2 lodicules, 6 stamens and the ovary with 3 stigmas.
J.F.
