Euphorbia susannae
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Euphorbia susannae |
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Euphorbia susannae is a succulent plant species in the genus spurge ( Euphorbia ) from the family of Euphorbiaceae (Euphorbiaceae).
The first plants were picked up by John Muir in 1925 . It was first described in 1929 by Rudolf Marloth . The species was named after Muir's wife Susanna. Since this female first name is sometimes also written Suzanna, there have been repeated publications in English-speaking countries under the synonym Euphorbia suzannae .
description
Euphorbia susannae are small, succulent shrubs with turnip to bulbous roots that only branch at the base. The pressed spherical to cylindrical branches are flattened on the front sides and have a diameter of about 3 to 7 cm. There are two different growth forms: In some populations , which also correspond to the original description, the plants branch underground. Here, the branches, which are only about three cm thick, remain mostly underground, so that only their ends are slightly raised and look out of the ground in about one level. In other populations, on the other hand, the plants branch roughly at ground level and then form dense, arched cushions of up to 30 cm in diameter with branches up to seven cm thick . The 12 to 16 ribs of the plants are divided into vertical to slightly spiraling warts. These warts are initially hairy and tapered to a point, sometimes slightly curved outwards. On the tips of the warts sit thread-like, about two to three mm long, quickly decaying leaves .
These are dioecious, separate-sex plants ( diocesan ). The cyathia of the male plants stand solitary or simple cymes (with a central cyathium and two lateral cyathia) on stems about 4 mm high. The cyathia of the female plants are solitary, sessile. The five yellowish-green nectar glands of the cyathia are elongated oval and almost touch each other.
Purple to almost black capsule fruits with a diameter of about 4 mm are formed. When ripe, these explosively release the approximately 1.5 mm thick, almost spherical seeds .
Occurrence
This species only grows endemically in a fairly limited area within the small Karoo between Ladismith and Barrydale . In sandy to pebbly soils, the plants are almost always in the shade and protected by accompanying vegetation.
cultivation
In Central Europe , the growing season is mostly divided and ranges from March to May and then from July to September. The main flowering period is also divided and falls first in May and then in the range from October to November. Animal pests such as mealybugs are only a minor problem in culture. However, since the plants are very sensitive to waterlogging and in the case of bacterial and fungal infections often collapse irretrievably within a few days, the species is considered to be relatively difficult to cultivate.
Cultivated plants deviate somewhat from the typical appearance. They are usually less stocky, looser and often not just branched at the base and have longer cyathia stems than the plants in their natural habitat.
A variegated comb shape of the species can only be found in culture . This is almost exclusively offered in grafted form .
photos
Flat-growing plant in the habitat , near Barrydale , South Africa
Thread-like leaves in the apex area
Cyathia of a male plant
Single male cyathium
Female plant with fruits
literature
- Rudolf Marloth: Euphorbia susannae , S. African Gard. 19: 191, 1929
- A. White, RA Dyer & BL Sloane: The Succulent Euphorbiae , 1941
- Keith Grantham: Home and away , Euphorbia Studygroup Bulletin, 13 (3), 2000
- Rikus van Veldhuisen: Euphorbia susannae Marloth, Euphorbia World 1 (1), 2005
