Oldeania Stapleton, 2013

Stapleton, Chris M. A., 2013, Bergbambos and Oldeania, new genera of African bamboos (Poaceae, Bambusoideae), PhytoKeys 25, pp. 87-103 : 98

Oldeania Stapleton gen. nov.

Remarks.

Differing from Arundinaria and Sarocalamus and similar to Yushania in its long-necked pachymorph rather than leptomorph rhizomes, though similar to all in its open panicles. Differing from Yushania in its sulcate culm internodes, fewer, more horizontal branches, culm nodes with well developed supra-nodal ridge and often thorn-like aerial roots. Similar to Chimonocalamus in its panicles and thorn-like roots at culm nodes, but differing in its multiple branches with reduced sheathing and sulcate culm internodes.

Type.

Oldeania alpina (K. Schum.) Stapleton comb. nov. urn:lsid:ipni.org:names:77131105-1 Basionym Arundinaria alpina K. Schum. in Engler, Pflanzenwelt Ost-Afrikas 5: 117. 1895. Sinarundinaria alpina (K. Schum.) C.S. Chao & Renvoize; Yushania alpina (K. Schum.) W.C. Lin. Type: Kenya, Kikiju, G.A. Fischer 672 (holotype: B n.v., destroyed).

Rhizome pachymorph, long-necked, giving open stands and solitary culms. Culms to 15(-20) m tall, diam. to 6(-10) cm, erect to nodding, terete with shallow sulcus above branches, smooth, nodes with prominent supranodal ridge, in lower to mid culm a nodal ring of dense, short, hard, and thorn-like aerial roots often well developed. Mid-culm branch complement initially with 3-5 main branches, spreading, sheathing reduced. Culm sheaths deciduous, tough. Leaf sheaths several to very many, blades thick. Synflorescence semelauctant, paniculate, branch sheathing reduced to hard bracts, soft sheath remnants or hairs. Spikelets pedicellate with several fertile florets, pedicel scabrous. Empty glumes 2, bud remnants present or absent, fertile glumes 4-8. Lemma and palea similar in length. Stamens 3, filaments free. Stigmas 2. Lodicules 3.

Name Oldeania from the Maasai common name (Oldeani) in Tanzania.

Currently only the type species can be reliably placed in the genus, which thus has a distribution across tropical Africa from Cameroon in the west to E Africa, where it occurs from Ethiopia south to Tanzania. There is a possibility that species from Madagascar will be placed in this genus when they are better known, but they may be conspecific or even introduced. It provides important montane wildlife habitats and food, notably for the critically endangered Mountain Gorilla, Gorilla beringei beringei .

The holotype, G.A. Fischer 672, was destroyed by fire during the 1939-1945 World War. No trace of the type collection or any duplicate has been found in surviving components of the Berlin collections, nor in other herbaria, including the Hamburg collections taken to Russia and recently repatriated (Poppendieck pers. comm.). The likelihood of substantial infraspecific variation, the possibility of further species, and the lack of other collections from the type locality together make it inadvisable to select a neotype or epitype until new collections have been made.