Critically Endangered Gladiolus roseovenosus

Gladiolus roseovenosus is a rare winter rainfall species that grows in peaty sandstone soil on well drained slopes in the coastal foothills of the Outeniqua Mountains in the southern Cape. According to SANBI (South African Institute for Biodiversity), G. roseovenosus was estimated (when assessed in 2008) that there were no more than 200 plants remaining in the wild. Historically these plants were only known from 4 populations found in the Western Cape. One population was destroyed by afforestation and the remaining populations had no more than 20 plants each.

This beautiful plant was first observed on Gondwana in 2019 by the Gondwana Conservation Foundation (GCF). The GCF has been monitoring and conducting research ever since.

Gladiolus roseovenosus: roseovenosus = red-veined, named for the striking markings on the petals. Characteristics: Plants grow 20 to 40 cm high. The long tubed creamy pink unscented flowers have red / deep pink nectar guides. These nectar guides or markings are thought to guide insects into the centre of the bloom possibly to assist in pollination.
Local Common name: Ruiterbospypie.
Family: Iridaceae.
Status: Critically Endangered.
Distribution: George to Robinson pass near Ruiterbos.
Flowering Time: Blooming time is summer into fall, between February and April.

Description: G. roseovenosus is a beautiful delicate gladiolus species with fairly large striking blooms. A 30-50cm tall deciduous geophyte with 4 leaves, the short blade is 1.5-2mm wide, the margins and midrib are thickened. The large flowers are a pale white to pink with red feathery streaks / guides mainly on the lower tepals. Capsule description and seeds are unknown.

Ecology: It grows on peaty sandstone derived soils on flat areas or gentle slopes. Pollinators have not yet been observed, however it is believed to be pollinated by long-tongue flies. The department is working on the pollinators and has had some success with capsule and pods sightings.

Gondwana Game Reserve:
On Gondwana, G. roseovenosus was first observed in 2019 in Red hartebeest Valley by the Gondwana Conservation Foundation (GCF) research team. Thereafter here are the plants that have been found to-date;

  • In 2020 the GCF found another 60 plants from 3 different locations (Red hartebeest Valley, West of Jo’s Bridge and Protea Forest).
  • In 2021 45 plants from 4 locations were observed with one new population being identified in Lehele valley.
  • In early February 2022, 14 plants were observed in a newly burnt block from Lehele-West to Lehele. It is believed that the plants are stimulated by fire.

The GCF are currently monitoring and mapping data on these plants. It is our goal to provide SANBI with additional information so that they may update the species information and status on this plant.

We appeal to all our citizen scientists to share any information and photos of G. roseovenosus with or without insects on the bloom that they may have taken. This information is valuable to the GCF’s research.

We look forward to updating you in the future with more info on this spectacular bloom.

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