Topic
Disa draconis
About: Disa draconis is a research topic. Over the lifetime, 4 publications have been published within this topic receiving 373 citations. The topic is also known as: Dragon Disa & White Disa.
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TL;DR: In this paper, the authors tested the hypothesis that divergence in spur length has resulted from selection exerted through pollinator proboscis length and found that selection on spur length occurs mainly through the female component of reproductive success.
Abstract: Field studies in South Africa showed that floral spur length in the Disa draconis complex (Orchidaceae) varies enormously between populations in the southern mountains (means = 32-38 mm), lowland sandplain (mean = 48 mm), and northern mountains (means = 57-72 mm) We tested the hypothesis that divergence in spur length has resulted from selection exerted through pollinator proboscis length Short-spurred plants in several southern mountain populations, as well as long-spurred plants in one northern mountain population, were pollinated by a horsefly, Philoliche rostrata (Tabanidae), with a proboscis length that varied from 22 to 35 mm among sites Long-spurred plants on the sandplain were pollinated by the tanglewing fly, Moegistorynchus longirostris (Nemestrinidae), which has a very long proboscis (mean = 57 mm) Selection apparently favors long spurs in sandplain plants, as artificial shortening of spurs resulted in a significant decline in pollen receipt and fruit set, although pollinaria removal was not significantly affected Fruit set in the study populations was limited by pollen availability, which further suggests that selection on spur length occurs mainly through the female component of reproductive success
347 citations
TL;DR: The systematic status of Disa draconis (L.f.) Sw.
20 citations
TL;DR: It is found that Philoliche gulosa Wiedemann (Tabanidae) is a pollinator of the putative floral model, Pelargonium stipulaceum and its floral mimic, Disa karooica, and the occurrence of a new floral model-mimic system in the semiarid interior of South Africa is proposed.
13 citations
TL;DR: The systematic status of Disa draconis (L.f.) is revised following extensive field studies of population variation in the Western Cape, South Africa, revealing clear distinctions between populations from sandplain, semi-arid and montane environments and suggesting the existence of a species complex.
3 citations