African violets
| African violets | ||||||||||||
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African violets ( Saintpaulia ionantha hybrid) |
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| Saintpaulia ionantha | ||||||||||||
| H. Wendl. |
The African violet is a type of plant from the Gesneriae family (Gesneriaceae). The pure botanical species ( Saintpaulia ionantha ) still grows wild in the Usambara Mountains in Tanzania , from which the name "African violets" is derived.
The cultivated African violet ( Saintpaulia ionantha hybrid) is descended from species and subspecies originally native to Tanzania . The African violet got its common German name because the species Saintpaulia ionantha was found in the Usambara Mountains . The part of the name "violets" refers to the fact that there were violet, that is, violet-colored, Saintpaulia first ; The African violet is not closely related to the genus violet ( Viola ).
Propagation: leaf cuttings, sowing.
description
Today nine subspecies are distinguished, each of which differs in a complex of characteristics. Transitional forms in areas of overlap make the distinction difficult. The following features are largely common:
Vegetative characteristics of the wild forms
The wild forms of Saintpaulia ionantha are tropical, evergreen, perennial herbaceous plants . They thrive in the herb layer in the shade of the woods or on damp rocks. It grows rosette-shaped to creeping stalk-forming (caulescent). The initially hairy stem is compressed, short and robust or slender and up to 20 cm long; sometimes it is branched.
The leaves, which are usually arranged in rosettes and divided into petioles and blades, are fleshy to very thin and light green to purple-red. The usually 3 to 15 (1 to 24) cm long petiole has long and / or short hairs that protrude to different degrees and can be pressed. The leaf blade is egg-shaped, (oblong) elliptical or circular with a heart-shaped base, with a length of 1.7 to 12.5 cm and a width of 1.5 to 9.5 cm, sometimes it is asymmetrical; there are four to seven pairs of lateral nerves. The leaf margins are more or less wavy, (wavy) sawn or almost smooth. The top of the leaf has very different hairs depending on the subspecies.
Generative characteristics of the wild forms
On the side of a 1.5 to 10 (to 15) cm long, hairy inflorescence stem is a sometimes branched inflorescence with one to twelve flowers. The hairy flower stalks are 7 to 36 mm long. The hairy bracts are linear to oblanceolate and 1 to 7.5 mm long. The five-fold, hermaphroditic, slightly zygomorphic flowers are also usually slightly hairy with a double flower envelope ( perianth ). The five sepals are fused at their base with lanceolate calyx lobes which are 1.5 to 4 (up to 6) mm long during the flowering period and enlarge slightly until the fruit is ripe; their outside is hairy differently. The color of the petals is different in the subspecies. The five petals with different hairs on the outside and on the edges are fused to form a (1.2 to) 1.5 to 3 mm long tube. There are two crown lips. The upper corolla lip is 5 to 12 mm long with (elongated) rounded, 3 to 9 mm long and wide corolla lobes. The lower corolla lip is 6.5 to 19.5 mm long with (elongated) rounded to approximately obovate, 4 to 12.5 mm long and 4 to 14 mm wide corolla lobes. In wild forms only two stamens are fertile. The robust, large anthers are kidney-shaped and bright yellow. The flattened stamens are usually 2.5 to 3.5 (2 to 4) mm long. The theca are (1.3 to) 1.7 to 2.7 mm long. The two to three staminodes are tiny. The ovoid to conical ovary is 1 to 3.5 mm long and hairy. The 3 to 7.5 mm long stylus ends in a slightly bilobed scar, which has a diameter of 0.3 to 0.6 (to 0.9) mm and is papillary .
The egg-shaped to narrowly cylindrical capsule fruit with a length of 7 to 30 mm and a diameter of 1.5 to 5 mm wide has a surface with different hairs and a more or less easily recognizable style. The only 0.4 to 0.65 mm long seeds are warty with longitudinal crests.
Different characteristics of the cultivated forms
Cultivated African violets are larger in all characteristics. The evergreen, perennial herbaceous plants are not hardy. The leaves are in rosettes, which, depending on the variety, reach heights and plant diameters of around 10 to 20 cm. The African violet varieties can bloom all year round. The inflorescences contain more flowers than in wild forms. The petals are smooth-edged or fringed depending on the variety. Double-flowered varieties were also bred. With the varieties, the palette of the colors of the petals extends from the various shades of blue to pink and white to red-violet; there are single or multi-colored flowers. In cultivated forms, more than two to all five stamens can be fertile.
Systematics
Saintpaulia ionantha was founded in 1893 by Hermann Wendland in Gartenflora , 42, 321, plate 1391, fig. 66 first published as a type of the genus Saintpaulia . The generic name Saintpaulia honors the sender of the type species, the German colonial official in East Africa Walter von Saint Paul-Illaire (1860–1940). The specific epithet ionantha means "violet-flowered" and refers to the color. The original description of Saintpaulia ionantha was made from living specimens cultivated from seeds sent from Saint-Paul-Illaire. No herbarium material from the type collection has been preserved. These seeds were collected from two locations that are now the original locations of the two subspecies Saintpaulia ionantha subsp. ionantha and Saintpaulia ionantha subsp. are grotesque . Particularly in this genus, herbarium material differs in many characteristics from living specimens, especially since the hair is no longer equally well preserved. This shows how difficult it is for historical reasons and remains to deal scientifically with this type.
A number of earlier Saintpaulia species from Tanzania are now classified as a subspecies or variety of Saintpaulia ionantha :
- Saintpaulia ionantha H. Wendl. subsp. ionantha (Syn .: Petrocosmea ionantha (H Wendl.) Rodigas , Saintpaulia ionantha var. albescens Bedd. nom. nud., Saintpaulia ionantha var. purpurea Bedd. nom. nud., Saintpaulia ionantha var. violacea Bedd. nom. nud., Saintpaulia kewensis C.B.Clarke in Dyer, Saintpaulia tongwensis B.L.Burtt )
- Saintpaulia ionantha subsp. grandifolia (BLBurtt) I.Darbysh. in Beentje, HJ & Ghazanfar, SA (Syn .: Saintpaulia grandifolia B.L.Burtt )
- Saintpaulia ionantha subsp. grotei (Engl.) I.Darbysh. in Beentje, HJ & Ghazanfar, SA (Syn .: Saintpaulia grotei Engl. , Saintpaulia amaniensis E.Roberts , Saintpaulia confusa B.L.Burtt , Saintpaulia difficilis B.L.Burtt , Saintpaulia diplotricha sensu Burtt . type, excl, Saintpaulia magungensis E.Roberts , Saintpaulia magungensis var. minima B.L.Burtt )
- Saintpaulia ionantha subsp. mafiensis I.Darbysh. in Beentje, HJ & Ghazanfar, SA
- Saintpaulia ionantha subsp. occidentalis (BLBurtt) I.Darbysh. in Beentje, HJ & Ghazanfar, SA (Syn .: Saintpaulia magungensis var. occidentalis B.L.Burtt )
- Saintpaulia ionantha subsp. orbicularis (BLBurtt) I.Darbysh . in Beentje, HJ & Ghazanfar, SA (Syn .: Saintpaulia orbicularis B.L.Burtt , Saintpaulia orbicularis var. purpurea B.L.Burtt )
- Saintpaulia ionantha subsp. pendula (BLBurtt) I.Darbysh. in Beentje, HJ & Ghazanfar, SA (Syn .: Saintpaulia pendula B. L. Burtt , Saintpaulia intermedia B.L.Burtt , Saintpaulia pendula var. kizarae B.L.Burtt )
- Saintpaulia ionantha subsp. velutina (BLBurtt) I.Darbysh. in Beentje, HJ & Ghazanfar, SA (Syn .: Saintpaulia velutina B.L.Burtt )
- Saintpaulia ionantha var. Diplotricha (BLBurtt) I.Darbysh. in Beentje, HJ & Ghazanfar, SA (Syn .: Saintpaulia diplotricha B.L.Burtt )
The Saintpaulia ionantha hybrids were bred from some of these subspecies and varieties, but also with the participation of other species ( e.g. Saintpaulia confusa ) .
African violet hybrids ( Saintpaulia ionantha hybrids)
Culture in the workplace
Mostly specialized ornamentals growers cultivate African violet hybrids in large quantities.
The propagation takes place mostly via cuttings. Particularly beautiful, healthy specimens are selected as mother plants. The mother plants can be used for about two years. The temperature is set to 20 to 25 ° C all year round. In order to obtain cuttings all year round, an additional light of 40 watts per m² is provided from mid-October to the end of February. Leaf cuttings can be taken about every four weeks. Leaf cuttings are cut to a stem length of two to three cm. The leaf cuttings are stacked in a nutrient-poor peat sand mixture. The rooting period is three to four weeks. The adventitious shoots appear after about six weeks .
There is also the possibility of sowing. 1 g of seeds has 25,000 grains, the weight of one thousand seeds is 0.2 g. They are light germs . At a temperature of 20 to 25 ° C, the germination time is only five days.
It takes three months from the leaf sticking to the budding ready for pricking. Several adventitious shoots usually form on a leaf cutting. These are torn apart and pricked out individually .
In the summer it must be shaded. The cultivation time can be shortened by assimilation light in winter. Plants for normal sizes are potted in 8 to 9 cm pots, for large plants in 10 to 11 cm pots, and for mini plants in 6 to 7 cm pots. It should not be potted too loosely, whereby the vegetation point is positioned a little lower than the edge of the pot so that the leaves later rest on the edge of the pot and it is important that the heart of the plants is not covered with soil. It is potted in a medium fertilized substrate. The further culture takes place at 22 to 24 ° C. It is re-fertilized weekly. It is important that the irrigation water is not colder than 20 ° C. It is best to water with a damming. The final level is 35 to 45 m² per plant. The cultivation time from potting to sale is around three months in summer and one month longer in winter. Even during marketing and transport, the temperature must not fall below 10 ° C.
Variety selection
There are a very large number of varieties. Over 2000 varieties are registered in the USA alone; there they are one of the most popular flowering house plants as "African Violet". Members of a plant society deal with their varieties.
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Variety groups
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Blue
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Pink
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Red
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White
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Colorful
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Trivia
The 123rd episode in the crime scene series from 1981 is entitled "African violets".
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Web links
- African Violet Society of America - American African Violet Society. (engl.)
- African Violet Varieties Gallery.
- African violets information page
literature
- Iain Darbyshire: Gesneriaceae , 2006, In: HJ Beentje & SA Ghazanfar (editors): Flora of Tropical East Africa : Online. (Section description and systematics of wild forms)
Individual evidence
- ↑ Gordon Cheers (Ed.): Botanica: The ABC of plants. 10,000 species in text and images . Könemann Verlagsgesellschaft, 2003, ISBN 3-8331-1600-5 (therein page 809).
- ↑ World Checklist of Gesneriaceae Query Results - Gesneriaceae Research: Saintpaulia ionantha .
- ↑ Karl rooms: main crops in ornamental , 3rd edition, 1991, 418 pages, Eugen Ulmer, ISBN 3800151340 : Saintpaulia-Ionantha hybrids on page 355-366.