Drosera insolita
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| Drosera insolita | ||||||||||||
| Taton |
Drosera insolita is a species of plant fromthe sundew family (Droseraceae). It is a carnivorous plant and wasfirst describedasnative tothe Congo . Presumably, however, it does not represent a species of its own, but its first description goes back to an error.
description
Drosera insolita is a perennial herbaceous plant . The sprout axis arises from a small tuber and runs 1 to 1.5 centimeters underground, from where short roots arise. The above-ground part is bare in all parts, upright, unbranched or branched in bundles at the base, slender and around 12 centimeters high.
The leaves are at the base in a floor-shaped rosette, the semicircular blade is around 3 millimeters long and 1.5 millimeters wide, occasionally shorter and scaly, the petiole is around 3.5 millimeters long. The leaves on the stem are stalked much longer with 7 to 10 millimeter long stems, occasionally they are slightly bent down. The semicircular blade has an umbrella-like stalk, at the corners are tentacles up to 3.5 millimeters long. The blade is 2 millimeters long and 4 millimeters wide, the stem and petioles are purple.
The simple inflorescences have three to four flowers . The up to 6.5 millimeters long flower stalks are almost vertical. The 1.5 to 2 millimeters long and at the tip 0.3 millimeter wide bracts are linear-spatulate and lobed two to four times at the tip. The oval sepals are spotted, serrated irregularly at the edges, around 3 millimeters long and 1.5 millimeters wide. The white petals are spatulate-egg-shaped, blunt at the extreme end, becoming slimmer towards the base, membranous and finely nerved. They are up to 6 millimeters long and 3 millimeters wide.
The stamens are 3 millimeters long, the anthers 0.5 millimeters. The round ovary measures around 1.5 millimeters in diameter. The three styles are branched dichotomously and around 1 millimeter long. The numerous small seeds are egg-shaped.
distribution
The only find of the species is said to come from Haut-Katanga in the extreme southwest of the Democratic Republic of the Congo. There is no further information on the habitat. It may be found there in so-called Dembos or in humus-rich soils of savannahs .
Systematics and botanical history
The species was first described by Auguste Taton in 1945 after he came across the specimens collected by Henri Antoine Homblé in 1911 as part of the preparatory work for his processing of the sundew plants in the "Flore du Congo" in the Brussels Botanical Garden .
No further collections are known, new collections are difficult because the herbarium specimen does not have an exact location, apart from the information about the province.
Drosera insolita is strikingly similar to Drosera peltata , a species of the so-called bulbous drosera that can be found from China to Australia. This group, which is otherwise only native to Australia, corresponds within the genus to the subgenus Ergaleium , in whose section of the same name Taton also placed it. This would make Drosera insolita the only representative of the tuberous drosera in Africa.
However, the status as a separate species is extremely dubious, as it probably goes back to an error in the assignment of the type specimen . Homblé had not only collected in the Congo, but also in China, where Drosera peltata is native. In 1978 Taton redefined the type specimen as Drosera peltata var. Lunata and provided it with notes on its origin from China. A correct synonymization of Drosera insolita is still missing, which is why the description remains formally valid.
Danger
This species is seriously threatened in its population due to the destruction of its habitat as a result of mining activities. The IUCN lists them in the Critically Endangered category .
literature
- Auguste Taton: Nouveaux Drosera du Congo Belge. In: Bulletin du Jardin Botanique de l'Etat à Bruxelles. Vol. 17, No. 3/4, 1945, ZDB -ID 421744-5 , pp. 307-311.
Individual evidence
- ↑ a b Entry in the African flowering plants database , online , accessed on February 10, 2009
- ↑ entry to Homblé in The BR Herbarium Catalog of the National Botanic Garden of Belgium, Online
- ^ Illustration of the holotype in The BR Herbarium Catalog of the National Botanic Garden of Belgium, Online
- ↑ Drosera insolita in the Red List of Endangered Species of the IUCN 2013.2. Listed by: Riddick, R., 2018. Retrieved May 19, 2014.