Book contents
- Frontmatter
- Contents
- Introduction
- List of symbols and abbreviations
- 1 Species associations
- 2 Vegetation in West Africa
- 3 Annonaceae – soursop family
- 4 Amaranthaceae – amaranth family
- 5 Cucurbitaceae – gourd family
- 6 Ochnaceae – ironwood family
- 7 Combretaceae – afara family
- 8 Guttiferae (Clusiaceae) – butter tree family
- 9 Sterculiaceae – cocoa family
- 10 Bombacaceae – silk cotton family
- 11 Malvaceae – cotton family
- 12 Euphorbiaceae – cassava family
- 13 Caesalpiniaceae – pride of Barbados family
- 14 Mimosaceae – Acacia family
- 15 Papilionaceae – cowpea family
- 16 Ulmaceae – afefe family
- 17 Moraceae – mulberry family
- 18 Meliaceae – mahogany family
- 19 Sapindaceae – akee apple family
- 20 Anacardiaceae – cashew nut family
- 21 Sapotaceae – sheabutternut family
- 22 Apocynaceae – frangipani family
- 23 Asclepiadaceae – blood flower or milkweed family
- 24 Rubiaceae – abura family
- 25 Compositae (Asteraceae) – Tridax family
- 26 Solanaceae – tomato family
- 27 Convolvulaceae – sweet potato family
- 28 Bignoniaceae – jacaranda family
- 29 Acanthaceae – Thunbergia family
- 30 Verbenaceae – teak family
- 31 Labiatae (Lamiaceae) – Hausa potato family
- 32 Commelinaceae – day flower family
- 33 Zingiberaceae – ginger family
- 34 Marantaceae – (West Indian) arrowroot family
- 35 Liliaceae – lily family
- 36 Araceae – cocoyam family
- 37 Palmae (Arecaceae) – palm family
- 38 Orchidaceae – orchid family
- 39 Cyperaceae – sedge family
- 40 Gramineae (Poaceae) – grass family
- General bibliography
- Index of family, generic and common names
25 - Compositae (Asteraceae) – Tridax family
Published online by Cambridge University Press: 02 November 2009
- Frontmatter
- Contents
- Introduction
- List of symbols and abbreviations
- 1 Species associations
- 2 Vegetation in West Africa
- 3 Annonaceae – soursop family
- 4 Amaranthaceae – amaranth family
- 5 Cucurbitaceae – gourd family
- 6 Ochnaceae – ironwood family
- 7 Combretaceae – afara family
- 8 Guttiferae (Clusiaceae) – butter tree family
- 9 Sterculiaceae – cocoa family
- 10 Bombacaceae – silk cotton family
- 11 Malvaceae – cotton family
- 12 Euphorbiaceae – cassava family
- 13 Caesalpiniaceae – pride of Barbados family
- 14 Mimosaceae – Acacia family
- 15 Papilionaceae – cowpea family
- 16 Ulmaceae – afefe family
- 17 Moraceae – mulberry family
- 18 Meliaceae – mahogany family
- 19 Sapindaceae – akee apple family
- 20 Anacardiaceae – cashew nut family
- 21 Sapotaceae – sheabutternut family
- 22 Apocynaceae – frangipani family
- 23 Asclepiadaceae – blood flower or milkweed family
- 24 Rubiaceae – abura family
- 25 Compositae (Asteraceae) – Tridax family
- 26 Solanaceae – tomato family
- 27 Convolvulaceae – sweet potato family
- 28 Bignoniaceae – jacaranda family
- 29 Acanthaceae – Thunbergia family
- 30 Verbenaceae – teak family
- 31 Labiatae (Lamiaceae) – Hausa potato family
- 32 Commelinaceae – day flower family
- 33 Zingiberaceae – ginger family
- 34 Marantaceae – (West Indian) arrowroot family
- 35 Liliaceae – lily family
- 36 Araceae – cocoyam family
- 37 Palmae (Arecaceae) – palm family
- 38 Orchidaceae – orchid family
- 39 Cyperaceae – sedge family
- 40 Gramineae (Poaceae) – grass family
- General bibliography
- Index of family, generic and common names
Summary
Although very large on a world basis (20,000 species) the family is only modestly represented in West Africa, by under 300 species. These are mostly annual or perennial herbs or undershrubs, with alternate and/or opposite, simple exstipulate leaves, a few genera having milky juice (Berkheya and the Cichorieae tribe).
Members of the family may be recognised by the inflorescence, a racemose head ‘composed’ of very small flowers (florets), each gamopetalous and, if ♀ or with an inferior ovary. The axis (‘receptacle’) of the head is surrounded by an involucre of bracts, a feature also seen in Protea (p. 58), which fortunately possesses other distinguishing characters. The heads (in spikes) are ♂ (above) and ♀ (below) only in Ambrosia maritima, a whitely hairy undershrub in drier savannas. Compound heads (heads of heads) are seen only in Echinops and Elephantopus (white, blue or mauve heads), Sphaeranthus (red-purple heads) and Blepharispermum. B. spinulosum is a scrambling shrub (Côte d'lvoire– Ghana) with greenish-white compound heads, in forest regrowth. It is one of the few West African woody species and it has unique spines, one pointing down the stem from the base of each petiole.
In ‘woody’ species, no great quantity of wood is developed (see under Microglossa and Vernonia below). The remaining species which can be considered woody are of restricted distribution, i.e. Pluchea spp. in dry savannas from Sénégal to Sudan, Tanzania and Angola; Erlangea and Mikaniopsis spp. of upland shrubs and shrubby climbers from Guinée–E.
- Type
- Chapter
- Information
- Flowering Plants in West Africa , pp. 221 - 227Publisher: Cambridge University PressPrint publication year: 1988