Agroforestree Database

Local names:
 English (East African camphor wood,camphor), Swahili (mkulo), Trade name (East African camphor wood,camphor)

Ocotea usambarensis is a large tree, 3.5-36 (max. 45) m high with a spreading crown and stem diameter of (min.1.25) 3.75-9.5 m. Bole straight, slightly fluted, buttressed at the base, unbranched for 9-15 m. Bark grey or reddish brown, much fissured, granular, scaly and flaking off in small round patches or thick squares; slash white or faintly pink with a characteristic sweet scent.

Leaves opposite (alternate on sucker shoots), simple, elliptic to elongate-ovate or almost round, 4-16.5 cm long, 2.5-9 cm wide, dark green above, whitish below and camphor scented; margin rolled under in mature leaves, glabrous to shortly tomentose or pubescent with spreading ferruginous hairs, rounded to sharply acuminate at the apex, cuneate, rounded or truncate at the base, venation closely reticulate above, lateral nerves impressed above; veins wavy and brown; petiole 0.5-2.2 cm long. 

Cymose panicles tomentellous, axillary and terminal, 1.2-2.5 cm long, greyish or ferruginous, pubescent; peduncles 2-5 cm long; pedicels less than 2 mm long; bracts ovate about 2 mm long, obtuse, densely pubescent, soon deciduous. Perianth green, whitish or yellow, pubescent, about 1.5 mm long; inner lobes ovate, outer elliptic-oblong, 3 mm long, spreading. Separate male and female flowers, 8-10, each 5 mm long, yellow-white-green, hairy, stalked, held in a calyx cup. Stamens of hermaphrodite flowers with linear filaments as long as anthers; stamens of 3rd whorl with yellow, subglobose sessile or shortly stalked glands inserted on either side at the base; staminodes filiform, 1 mm long with dark tip. Female flowers with stamens and staminodes much reduced. Ovary ovoid, glabrous; style slender, 1 mm long; stigma discoid.

Fruit a glabrous drupe, ellipsoid or globose, 8-11 x 1-6.5 mm, borne in a cup 4-6 mm wide and 2-3 mm long, smooth and green when mature; pedicel thickened below cup. Seeds very small and surrounded by pulp.

Ecology

O. usambarensis is found in diverse mountain forest associations, the so-called ocotea forest. The tree is distributed throughout East Africa and common in wetter forests. Where it occurs naturally, there is a distinct dry season of 2-3 months, but with mist or clouds present throughout the year. It is found mainly in Kenya and Tanzania and sparsely in Uganda. In Kenya, it occurs on the moist slopes of the Aberdares, Mt Kenya, Taita Hills and Nyambene; it was once a dominant tree in the wet forests of these areas but is now rare everywhere. In Uganda, it occurs in upland and mountain forests, commonly in the Impenetrable (Bwindi), Kalinzu and Kasyoha-Kitomi Forests. In Tanzania, it occurs on Mt Kilimanjaro, the Usambara, Pare and Uluguru Mountains, and in Tukuyu and Iringa.

Native range
Kenya, Tanzania, Uganda

Tree management

O. usambarensis is fast-growing and responds well to coppicing.

Seed storage behaviour is recalcitrant, but seed can be stored in containers with moist sawdust for a few days. On average, there are 15 000-20 000 seeds/kg.

O. usambarensis is found in diverse mountain forest associations, the so-called ocotea forest. The tree is distributed throughout East Africa and common in wetter forests. Where it occurs naturally, there is a distinct dry season of 2-3 months, but with mist or clouds present throughout the year. It is found mainly in Kenya and Tanzania and sparsely in Uganda. In Kenya, it occurs on the moist slopes of the Aberdares, Mt Kenya, Taita Hills and Nyambene; it was once a dominant tree in the wet forests of these areas but is now rare everywhere. In Uganda, it occurs in upland and mountain forests, commonly in the Impenetrable (Bwindi), Kalinzu and Kasyoha-Kitomi Forests. In Tanzania, it occurs on Mt Kilimanjaro, the Usambara, Pare and Uluguru Mountains, and in Tukuyu and Iringa.

Seeds are sensitive to desiccation and should be sown fresh. Pretreatment is not necessary; under ideal conditions, seeds germinate in 30-45 days, and the expected germination rate of mature, healthy and properly handled seeds is 45%. Regeneration by root suckers is also possible, as stumps sucker easily.

O. usambarensis is a good source of firewood and charcoal.

Timber:  The heartwood is light yellowish-brown, darkening to a deep brown on exposure; sapwood slightly paler, not clearly demarcated. The texture is medium to fine and even; grain interlocked producing a stripe figure; sometimes lustrous; timber has a distinct camphor scent. The wood seasons well and is resistant to acids and fungi but not to termites. It can be used for furniture, railway-coach frames, joinery, panelling, building poles and the production of veneer.

Medicine:  Bark or roots are pounded, water added and the resulting paste applied on swellings such as those on the throat and other tumours. Inner bark may be pounded, mixed with Brucea spp and Myrica salicifolia and taken in a meat soup as a remedy for abscess, whooping cough and measles. In Kenya, the Taita people boil the bark in water and use it to treat a fatal childhood disease called ‘nyago’ characterized by strong muscular contractions, stomach pains and disturbed breathing, or it may be scraped and the resulting powder used to dress wounds. Malaria and backache are treated using juice obtained from roots that have been pounded and soaked in water.