Ph.D. / Cussonia Thunb. is a genus of 21 species (including one that is currently undescribed) found in grasslands, woodlands and forests of sub- Saharan Africa, the Arabian Peninsula (Yemen) and the Comoro Islands. The genus generally has soft brittle branches, a fleshy underground tuber and fleshy roots. Despite these features, Cussonia is not found in the dry and arid regions of Africa. They are generally trees or shrubs, and less often lianes (C. thyrsiflora Thunb.) or suffrutices (C. corbisieri De Wild.). The tree forms usually grow between 4 to 20 m in height; however C. zimmermannii Harms can grow up to 45 m tall. Cussonia corbisieri has a large woody underground caudex with multiple 1 m tall, herbaceous stems. Probably the most distinguishing feature of this genus is the shape and size of the leaves. The palmately compound leaves are carried (in most cases) on the ends of the branches. The simple palmatisect leaves, such as in C. arborea Hochst. ex A.Rich. or C. natalensis Sond., are not subdivided into smaller leaflets, while the compound leaves increase in complexity from mono-palmately compound to multi-palmately compound. The multi-palmate compound leaves are carried on long petioles (up to 700 mm) having up to nine leaflets (up to 500 mm long), with each leaflet having two or more articulations bearing secondary leaflets (up to 400 mm long). These secondary leaflets can be subdivided into tertiary leaflets (up to 200 mm long).
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:7321 |
| Date | 02 November 2012 |
| Creators | De Villiers, Bernard Johann |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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