Rhizome neck 10-50 cm. Culms to 15(-20) m, to 6(–10) cm in diam., solitary, erect to nodding; nodes lightly raised, supra-nodal ridge conspicuously raised, persistent pubescent culm sheath base very evident, basal nodes and some mid-culm nodes especially on small culms with a prominent ring of short aerial roots; internodes terete or with light to distinct sulcation above branches especially on smaller culms, smooth, not grooved, to 60 cm long, initially pale green with very thin uniform deciduous glaucous wax, becoming glossy yellow-green with orange spots to orange. Branches initially 2-7, reflexed, developing very promptly but sometimes arrested when short and protected by tough sheaths, central dominant, others progressively smaller, lateral branches not all subtended by a sheath; buds triangular, open, budscales tall, 1-keeled, keels ciliate. Culm sheaths papery to leathery, apically triangular, deciduous, initially pale green, with dark to mid-brown, appressed hairs, basally and marginally denser; ligule truncate, long-fimbriate, blade reflexed, deciduous; auricles indistinct; oral setae several, spreading, from thick bases. Leaf sheaths glabrous, very persistent, continuous apical growth producing long sprays of up to 50 persistent sheaths, adaxial margin glabrous, abaxial margin ciliate; ligule to 1mm, obliquely truncate, glabrous; external ligule (callus) well developed, shortly ciliate; auricles small, indistinct to semi-circular, reflexed; oral setae several, white, to 1 cm long, thin, erect to spreading; blade thin, linear-lanceolate, apex shortly acuminate, 6-12(-15) cm in length, adaxially glabrous, abaxially minutely appressed-scabrous and proximally shortly pilose, venation distinctly tessellate. Synflorescence semelauctant, paniculate, branch sheathing reduced to hard bracts, soft sheath remnants or hairs. Prophyll and glumes not subtending buds. Spikelets pedicellate with several fertile florets, pedicel scabrous. Glumes 2, bud remnants present or absent, fertile glumes 4–8. Palea 2-keeled, usually equal in length to lemma. Lodicules 3. Stamens 3; filaments free. Lodicules 3. Stigmas 2.
Name Latin alpina ‘alpine’ referring to its montane habitat, at altitudes above 2200 m across equatorial Africa.
Used in Africa for making fences, furniture, and woven panelling, but not as extensively used as bamboos in Asia, yet. Provides shelter and food to several African primates, notably the Mountain Gorilla. Rare in cultivation but the upright culms with light foliage make it a very attractive species, worthy of more extensive use, although it is not very frost-hardy and requires high rainfall.
Oldeania alpina has been introduced to the west from unrecorded sources in Africa on several occasions, but most introductions have died, usually because the species is not as frost-hardy as might be expected from its name, the altitudes at which it grows in Africa, and its tessellate leaves.