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| Dessein, S.; Robbrecht, E.; Smets, E.. |
| Spermacoce heteromorpha Dessein (Rubiaceae, Spermacoceae) is newly described and illustrated. It grows on the Marungu highlands of the Democratic Republic of the Congo (D.R. Congo) at altitudes of 1800 to 1900 m. The species resembles the Tanzanian Spermacoce taylorii Verdcourt, from which it mainly differs in having terminal inflorescences, only slightly exserted anthers, and densely pubescent stems. Moreover, Spermacoce heteromorpha features marked heterophylly, with long leaves at the plant’s base and much shorter cauline leaves, a type of heterophylly rarely observed in Spermacoce or in the Rubiaceae as a whole. The finding of this species exemplifies the unique floristic richness of this underexplored part of D.R. Congo. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Democratic Republic of the Congo; Heterophylly; Marungu highlands; Rubiaceae; Spermacoce. |
| Ano: 2006 |
URL: http://www.repository.naturalis.nl/record/407334 |
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| Dessein, S.; Harwood, R.; Smets, E.; Robbrecht, E.. |
| Complementary to the revision of the genus Spermacoce in the Northern Territory of Australia, pollen morphology of 48 of the 53 native Spermacoce species from the Northern Territory has been investigated by scanning electron and light microscopy. There is considerable variation for most diagnostic pollen characters. The average equatorial diameter (E) ranges from 10.5 to 41.7 μm. Grains are invariably colporate with apertures situated at the equator (being zonocolporate). The number of apertures varies from 3 to 17. The endoaperture is generally an endocingulum, often with a secondary thinning at the ectocolpus; one species has endocolpi. The sexine is usually perforate, but psilate, foveolate, and (micro)reticulate patterns were also found. Supratectal... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Spermacoce; Rubiaceae; Pollen morphology; Palynology; Australia; Northern Territory. |
| Ano: 2005 |
URL: http://www.repository.naturalis.nl/record/407293 |
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