2118.000 Thesium
Description of the genus
Annual or perennial herbs or subshrubs, parasitic or hemiparasitic. Leaves sessile, alternate, scale-like or ± linear. Flowers bisexual, solitary or in cymes, each flower subtended by 1, often conspicuous, bract which is often adnate to the pedicel or peduncle and 2 bracteoles or (in T. atrum and T. fastigiatum) by an involucre of 4 or more bracts. Perianth (3-4-)5-lobed, often with conspicuous external glands on the perianth tube below the sinuses of the lobes. Stamens as many as lobes; anthers (in ours) attached to lobes by tufts of hairs. Ovary with 3 ovules. Stigma capitate. Fruit a nut, rarely fleshy, usually 10-ribbed, crowned with the persistent perianth. Comment: A very difficult genus to identify in the field at species level. Almost all distinguishing features are based on measurements or characteristics of minute parts, which can only be seen and compared reliably under a microscope. Worldwide: 325 species in the Old World Zimbabwe: 24 taxa. Insects associated with this genus:
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Links to taxa: View: living plant images - herbarium specimen images - all images for this genus
| Species | FZ divisions | Content |
| asterias A.W. Hill | E | |
| atrum A.W. Hill | N,C | |
| brevibarbatum Pilg. | N,W,C,E | Description |
| breyeri N.E. Br. | C | |
| bundiense Hilliard [NrEnd] [LR-nt] | E | |
| chimanimaniense Brenan [NrEnd] [LR-nt] | E | |
| cymosum A.W.Hill | N,E,S | |
| dissitum N.E.Br. | N,W,C | |
| dolichomeres Brenan [NrEnd] [LR-nt] | E | Description, Image |
| fastigiatum A.W. Hill | N,C | Description, Image |
| goetzeanum Engl. | N,W,C,E | Description, Image |
| gracile A.W. Hill | W,C,E,S | |
| helodes Hilliard | N,C | |
| magnifructum Hilliard | N,W | |
| megalocarpum A.W. Hill | W,C | |
| multiramulosum Pilg. | C,E | |
| myriocladum Baker | W | |
| nigricans Rendle | E | Description, Image |
| pygmaeum Hilliard [NrEnd] | E | Description, Image |
| subaphyllum Engl. | N | |
| thamnus Robyns & Lawalrée | N | |
| unyikense Engl. | N | |
| ussanguense Engl. | E | |
| whyteanum Rendle | E | Image |
Other sources of information about Thesium:
Our websites:
Flora of Botswana: ThesiumFlora of Burundi: Thesium
Flora of the DRC: Thesium
Flora of Malawi: Thesium
Flora of Mozambique: Thesium
Flora of Rwanda: Thesium
Flora of Zambia: Thesium
External websites:
African Plants: A Photo Guide (Senckenberg): ThesiumBHL (Biodiversity Heritage Library): Thesium
EOL (Encyclopedia of Life): Thesium
GBIF (Global Biodiversity Information Facility): Thesium
Google: Web - Images - Scholar
iNaturalist: Thesium
IPNI (International Plant Names Index): Thesium
JSTOR Plant Science: Thesium
Mansfeld World Database of Agricultural and Horticultural Crops: Thesium
Plants of the World Online: Thesium
Tropicos: Thesium
Wikipedia: Thesium