Drehfrucht (Streptocarpus), auch eingedeutscht Streptokarpus genannt, ist eine Pflanzengattung in der Familie der Gesneriengewächse (Gesneriaceae). Ihre Heimat der etwa 135 Arten liegt hauptsächlich in den Wäldern des tropischen und südlichen Südafrikas und Madagaskars. Viele Sorten werden als Zimmerpflanzen verwendet.
Sowohl ihren deutschsprachigen Trivialnamen Drehfrucht als auch den botanischen Namen Streptocarpus bekam diese Pflanzengattung aufgrund der spiralig gedrehten, langen Früchte, welche von den meisten Arten gebildet werden. Der botanische Gattungsname Streptocarpus leitet sich aus den griechischen Wörtern: στρεπτός, streptos für gedreht und καρπός, karpos für Frucht ab.
Streptocarpus-Arten sind ein- bis mehrjährige, also monokarpe hapaxanthe Pflanzen oder meist ausdauernde, also pollakanthe, polykarpische Pflanzen. Sie wachsen als immergrüne, krautige Pflanzen, die selten an ihrer Basis verholzen. Der größere Teil der Arten ist acaulescent, das bedeutet die Sprossachse ist gestaucht. Einige Arten bilden mehr oder weniger lange Sprossachsen aus, die selbständig aufrecht, kriechend bis überhängend sind.
Die Laubblätter der meisten Arten sind in grundständigen Rosetten angeordnet. Ausnahmen sind einige Arten, welche nur ein einziges großes Blatt bilden, das durch ein Basalmeristem lebenslang wächst, wie zum Beispiel Streptocarpus wendlandii und Streptocarpus dunnii. Bei den Arten der Untergattung Streptocarpella sind die Laubblätter gegenstängig an den Stängeln entlang verteilt; zu ihnen gehört beispielsweise Streptocarpus saxorum. Die meist fein behaarten und leicht brechenden Laubblätter sind bei der Untergattung Streptocarpella mehr oder weniger lang gestielt und meist ungestielt. Die einfachen Blattspreiten sind bei der Untergattung Streptocarpus meist länglich und bei der Untergattung Streptocarpella meist fast kreisförmig, selten verkehrt eiförmig bis elliptisch.
Auf seitenständig an langen Blütenstandsschäften stehen die Blüten selten einzeln, meist zu einigen bis vielen in zymösen Blütenständen.
Die einzelnen Blüten halten einen Tag bis mehrere Wochen je nach Art. Die zwittrigen, zygomorphen Blüten sind fünfzählig mit doppelter Blütenhülle. Die fünf Kelchblätter sind meist frei oder höchstens an ihrer Basis verwachsen. Die fünf Blütenkronblätter sind röhrig verwachsen und die Kronröhre endet zweilippig. Die Farben der Kronblätter reichen von blau über violett und rosa bis rot und weiß. Von den zwei Paaren Staubblättern ist nur eines fertil, von dem anderen zu Staminodien reduziertem Paar fehlt meistens ein Staminodium. Die Staubfäden sind in der Mitte oft verdickt. Die Nektarien sind ringförmig oder kurz becherförmig. Zwei Fruchtblätter sind zu einem eiförmigen bis zylindrischen, unterständigen, meist einkammerigen Fruchtknoten verwachsen. Die Narbe ist je nach Art unterschiedlich.
Die mehr oder weniger zylindrischen, sich während der Entwicklung spiralig drehenden Kapselfrüchte, öffnen sich bei Reife mit einem Schlitz und die Spirale dreht sich auf, wenn sie alt sind. Dann springen sie in vier Klappen auf und enthalten viele Samen. Die sehr feinen (winzigen) Samen besitzen eine netzartige oder warzige Oberfläche. Ein Gramm Samen enthält circa 40.000 bis 80.000 Korn.
Von einigen Drehfrucht-Arten und -Hybriden werden Sorten als Zimmerpflanzen verwendet.[1]
Die Hauptblütezeit der Sorten reicht von Februar bis Oktober, die einzelnen Blüten halten einen bis mehrere Tage je nach Sorte. Die Blütenfarben der Sorten reichen von blau über violett und rosa bis rot und weiß. Auch Züchtungen mit mehrfarbigen Blüten gibt es.
Die Sorten der Drehfrucht mögen es entsprechend ihrer tropischen Herkunft ganzjährig warm ohne direkte Sonne und haben gern eine hohe Luftfeuchtigkeit. Beim Gießen ist darauf zu achten, nur auf die Erde, nicht aber auf oder zwischen die Blätter zu gießen, da dies zur Fäulnis führen kann. Bei mäßigem Gießen blüht die Drehfrucht lange und intensiv. Die Drehfrucht ist ein Lichtkeimer. Meist wird sie jedoch durch Blattstecklinge vermehrt.[1]
Die Gattung Streptocarpus wurde 1828 durch John Lindley in Botanical Register; Consisting of Coloured Figures of Exotic Plants Cultivated in British Gardens; with their History and Mode of Treatment, London, vol. 14 – Appendix to the first … A Sketch of the Vegetation of the Swan River Colony. …, Tafel 1173 aufgestellt. Die Typusart ist Streptocarpus rexii (Bowie ex Hook.) Lindl. Es gibt ein Homonym Streptocarpus Poech, das ein Synonym von Encalypta Hedw. in der Moosfamilie Encalyptaceae ist.[2]
Die Gattung Streptocarpus gehört zu den Didymocarpoiden Gesneriaceae innerhalb der Familie der Gesneriaceae. Bei manchen Autoren sind auch die Arten der Gattung Saintpaulia in die Gattung Streptocarpus eingegliedert. Die vier asiatischen Arten gehören wahrscheinlich zu anderen Gattungen mit gedrehten Früchten. Die Gattung Streptocarpus ist in die zwei Untergattungen Streptocarpus (2n = meist 32 und Vielfache davon: 64, 96, 128) und Streptocarpella Engl. (2n = meist 30) gegliedert.
In der Gattung Drehfrucht (Streptocarpus) gibt es etwa 135 Arten (hier mit Angabe des Heimatlandes)[3]:
Die Gattung Streptocarpus ist seit langem ein Forschungsobjekt, bei dem verschiedene Aspekte der Botanik wie die Phylogenie und Ontogenie verschiedener Arten unter anderem mit Hilfe biochemischer und molekularbiologischer Methoden untersucht werden. Dieter Heß entdeckte 1961 die mRNA als Auslöser der Blühinduktion bei Streptocarpus wendlandii.
Drehfrucht (Streptocarpus), auch eingedeutscht Streptokarpus genannt, ist eine Pflanzengattung in der Familie der Gesneriengewächse (Gesneriaceae). Ihre Heimat der etwa 135 Arten liegt hauptsächlich in den Wäldern des tropischen und südlichen Südafrikas und Madagaskars. Viele Sorten werden als Zimmerpflanzen verwendet.
Streptocarpus ("twisted fruit" from Greek στρεπτός (streptos) "twisted" and καρπός (carpos) "fruit")[2] is an Afrotropical genus of flowering plants in the family Gesneriaceae. The genus is native to Afromontane biotopes[3] from central, eastern and southern Africa, including Madagascar and the Comoro Islands.[4] The flowers are five-petalled, salverform[5] tubes, almost orchid-like in appearance, and hover or arch over the plant, while the pointed, elongate fruit is of a helical form similar to that of the "tusk" of a narwhal. In the wild, species can be found growing on shaded rocky hillsides or cliffs, on the ground, in rock crevices, and almost anywhere the seed can germinate and grow. For the home, there are now many hybrids of various colours and forms available.
Although generally referred to simply as "Streptocarpus" or "Streps", the common name for subgenus Streptocarpus is Cape primrose, referring to the nativity of several species to South Africa and their superficial resemblance to the unrelated genus Primula. The common name for subgenus Streptocarpella is nodding violet. Streptocarpus sect. Saintpaulia ("African violet") is a separate section within Streptocarpus subgenus Streptocarpella.[6]
DNA studies have shown that, despite not having a twisted fruit, African violets evolved from within the Tanzanian Streptocarpus subgenus Streptocarpella.[4][7]
There are a few Asian species that have recently been removed from the genus, most notably Streptocarpus orientalis, now reclassified as Damrongia orientalis. Molecular systematics has shown conclusively that they are not true Streptocarpus.[8][9][10]
There are two subgenera within Streptocarpus, namely subgenus Streptocarpus and subgenus Streptocarpella.
Within the Streptocarpus subgenus Streptocarpus, there are two main forms, the plurifoliates and the unifoliates.
Streptocarpus with more than one leaf are called "plurifoliates", and there are two main types of these. First is the rosulate form, which is perennial. Rosulates are made up of a basal rosette of leaves. Flower stems sprout from the upper surfaces of the bases of these leaves. The most common Streptocarpus houseplant is of the rosulate type. The flowers of modern rosulate hybrids are generally three to several centimeters in diameter. The other plurifoliate type is essentially somewhere in between a rosulate and a unifoliate. In this group, two or three leaves grow in addition to the first leaf. The plurifoliates are perennial. Examples are Streptocarpus prolixus, and Streptocarpus polyanthus ssp polyanthus.[11]
The second form is the unifoliate, which only has one leaf. In the unifoliates group, one single leaf grows continuously from the base. Many unifoliates are also monocarpic, which means that they will flower once, set seed, then die. But they may take a few years to reach this stage. In other unifoliates, the original leaf may die, but one or two new leaves will sprout from it, and the plant continues to grow.[8]
This subgenus (comprising plurifoliates and unifoliates) is unique in that, in winter, they can form abscission lines part way down the leaf (see photo gallery below). The leaf then dies back to this point, whilst the proximal part of the leaf stays alive and healthy. In unifoliate species, the remaining healthy portion of that leaf will start to grow again from the base.[8]
Members of the Streptocarpus subgenus Streptocarpella are very different in form to those mentioned above.
The flowers and seed pods are similar, but the leaves and stems are caulescent (have stems). Streptocarpellas are generally clump-forming or trailing plants. Their flowers are only about 2.5-3.5 cm in diameter, and their colour range seems to be limited to mid-purples, pale pinks, and white.
Streptocarpella leaves can be decussate in arrangement (each pair of leaves at a node is at 90 degrees to the ones preceding or following it), or ternate (whorls of 3 leaves at each node). Some specimens may exhibit both on the same plant. Streptocarpella are grown as houseplants, hanging plants, and sometimes as bedding plants.
These two Streptocarpus subgenera do not interbreed.
For information on Streptocarpus subgenus Streptocarpella section Saintpaulia, see Streptocarpus sect. Saintpaulia.
Streptocarpus flowers are five-lobed, salverform,[5] zygomorphic tubes. The diagram at the right shows a labelled drawing of a vertical cross-section along the length of a Streptocarpus flower.
It is important to note that the two anthers (each arising from one filament on each side of the flower), are loosely joined together. As the anthers mature, they open slightly and act like a pepper shaker, which means that not all the pollen is released at once.
Streptocarpus flowers have evolved to be pollinated by birds, long-tongued flies, butterflies[12] and probably long-tongued moths and bees. Although almost any small insect, animal, or breeze could potentially pollinate Streptocarpus. Streptocarpus flowers often have nectar guidelines that guide would-be pollinators to the nectar (and anthers and stigmas). Self-pollination is also common.
About 155 species of Streptocarpus are currently recognized, the first to be described being Streptocarpus rexii.
A complete list of the species and their synonyms can be found at the Smithsonian's World Checklist of Gesneriaceae.[1]
A list of selected species from representative locales[1] follows:
Each grower will have their own preferences for cultivation. The details given below are a tested general guide, but Streptocarpus will do quite well on either side of these optimums.[13]
The two main things to remember when growing Streptocarpus are that they do not like soil that is too wet, and they do not like it too hot.
Soil: Use an ordinary commercial potting mix with 1/8 to 1/4 perlite mixed in. This makes sure the soil will retain some moisture but not get boggy. Always have adequate drainage holes at the bottom of the pot you are planting in.
Temperature: 18–25 °C (64–77 °F). They can be taken down to 10 °C (50 °F) or less in winter for a rest.
Light: Medium to bright indirect light is best. However, a bit of morning/late afternoon sun is more than okay. Even in dimmer light, they will flower - but less floriferously.
Water: Water only once the soil is almost dry. Some growers prefer to water only when the leaves have just started to wilt (or just before). They recover very well from dehydration, and this is one of the traits of the species. Make sure the pot has holes in the bottom to drain water, and never leave the pots sitting in a saucer of water.
Feeding: Feed occasionally with a "fruit and flower" or general fertilizer.
Seasons: Generally, Streptocarpus will flower from spring to autumn. In winter, they will stop flowering and may lose some leaves, which is normal. However, some varieties flower in winter.
Pruning of leaves & flowers: You may slice off yellowing or browned leaves at the base - these will be the older leaves naturally dying off. If there is a healthy leaf with some blemishing, you can successfully cut off only the blemished parts and trim the leaf to a normal shape. With regards to flowers, snip off individuals as they finish, then snip the whole stem off at the base once the last flower on that stem is spent.
Cut flowers: Streptocarpus flowers also make excellent cut flowers, especially the long-stemmed varieties. They last well.
Pests and diseases: Streptocarpus are generally pest and disease-free. However, the most common afflictions are aphids and mealybugs. These are easily treatable with commercial insecticides or cultural pest removal methods.
Leaves and abscission: It is common for older leaves to die off occasionally, but especially in winter. They may be snipped off. New leaves will replace them.
The leaves of some perennial, but usually unifoliate Streptocarpus, are unusual because, as winter approaches, they slowly die back to an abscission line midway down the leaf. The end portion of the leaf will gradually die back to this line. In most flowering plants, an abscission line forms at the base of the leaf, and the whole leaf will fall off (e.g. the leaves of deciduous trees like oak).
Propagation is usually either by seed or leaf cuttings. Some species produce plantlets from the roots,[14] which can be used to propagate the plant. Mature clumps of plants can also be divided up and repotted.
Streptocarpus species seed that has been self-pollinated will grow true to type.
Self-pollinated hybrid seed will not grow true to type. The only way to propagate hybrid plants and retain the characteristics of the hybrid, is by leaf propagation (or other types of vegetative cloning)
For Streptocarpus subgenus Streptocarpus:
By seed: Streptocarpus seed is generally very fine (see image gallery below). To germinate, the seed must be scattered thinly on top of potting mix, as they require light to germinate. The pot they are sown in must be covered in clear plastic “cling film” to keep up the humidity. Keep the sown seed where it will get bright, indirect light, and remain about 18-20 degrees Celsius. Keep them out of direct sunlight.
By leaf:
A Streptocarpus leaf can be severed at the base, taking some petiole (but above where flowers arise), and potted, base-down, in a few centimetres of potting mix. Place a clear plastic bag over the pot and secure with a rubber band to keep up the humidity.
Leaf segments, cut either horizontally across the leaf, or length-wise along the leaf (removing the midrib), can be used as cuttings in much the same way. Place the segments cut-side down in soil, as above. For unifoliates, this method is apparently less successful, but not impossible. However, it must be done before the plant flowers.
Streptocarpus leaves have a high concentration of cytokinin (a type of rooting hormone), so the use of artificial rooting hormones is unnecessary.
By root plantlet: Un-pot a plant that you know is susceptible to producing root plantlets (e.g. Streptocarpus johannis, and its sports ‘Falling Stars’ and 'Gloria'. You will see, once the roots are exposed, whether any plantlets have formed between the soil and pot.
Sometimes, these plantlets will be evident growing out of the holes at the bottom of the pot. You can then snip these plantlets off (preferably with their attached roots), and plant up as for leaf propagation above).
By clump division: You can divide a multi-crown clump into pieces (each with a root system), and plant up as for leaf propagation above.
For Streptocarpus subgenus Streptocarpella:
By seed: Streptocarpus seed is generally very fine. To germinate, the seed must be scattered thinly on top of potting mix, as they require light to germinate. The pot they are sown in must be covered in clear plastic “cling film” to keep up the humidity. Keep the sown seed where it will get bright, indirect light, and remain about 18-20 degrees Celsius. Keep them out of direct sunlight.
By stem cuttings: Cuttings of about 5–10 cm can be taken beneath a leaf node. When the cutting is placed in clean water, it will sprout roots. Keep the cuttings in bright, indirect light at about 18-20 degrees Celsius. Once the roots are about 5 cm long, you can pot up the cutting into the soil mixture mentioned above.
Hybridisation of Streptocarpus is conceptually very simple. The pollen of one plant (therefore the father) is placed onto the tip of the stigma of another plant (the mother). To prevent unwanted self-pollination of the mother plant, carefully remove its anthers beforehand. To help prevent unwanted cross-pollination, cover the newly fertilized stigma with a small plastic bag. If fertilization was successful, the seed pod will start to elongate within a few days. As the pod grows, it will start showing its namesake twisted form. Once the pod is mature, it will turn brown, dry off, and split open along the spiralled seams to release the seeds.
Another method that is used to create hybrids is to use radiation or chemicals to alter the genes. For example, irradiation may be used (e.g. xrays, gamma rays) to induce mutations that may give rise to plants with new characteristics. Another example is the use of colchicine to induce polyploidy (multiplying number of chromosomes) in plants, also to introduce new traits.
Over the years, numerous hybrids have been produced. S. rexii was used in many of the early hybrids, and its form is one that we most recognize in modern-day hybrids. But more recent hybrids may contain the genes of other species or hybrids. When making a cross, hybridizers keep in mind which traits they wish to bring out or improve in the progeny.
Much hybridizing work has been done to produce modern hybrids with an increased range of flower colours and forms, leaf variations, increased flowering periods, and more recently to introduce scent. Thanks to the work of hybridizers, Streptocarpus now come in a range of colours. These include reds, pinks, purples, blues, yellows, whites, and near-blacks. The only colour that is so-far not available is a true orange.[15]
Flowers now exist that are multicoloured, striped, spotted, veined, double, larger or smaller, and even fragrant and colour-changing. There are also variegated-leaf varieties, such as S. 'Canterbury Surprise'. Flower stems may be short or tall; leaves may be big or small; flowers may be full or dainty; and there may be one or many flowers per stem.
The following hybrid cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-
The following is a quick summary of 1950s publications by Lawrence and Sturgess,[43][44]
Colour genes
V = places pigment in the flower stems
F = places pigment in the petal cells
V and F are both necessary to give colour, but do not control which colour. When V or F are recessive (vv or ff) the flowers will lack any colour and will be white in appearance.
I = colour intensity. II = intense colour, Ii = medium colour and ii = pale colour. This gene doesn't control "which colour", just how "intense" the final colour will be in appearance.
The actual flower colour genes are named O, R, and D. Where the second copy of the gene is given as a "_", the second copy can be either dominant or a recessive. For example, in blue flowers, only one dominant of each the three genes is needed (e.g. the O gene could be either OO or Oo, and it wouldn't matter which).
Blue = O_R_D_
Magenta = ooR_D_
Pink = oorrD_
Mauve = O_R_dd
Rose = ooR_dd
Salmon = oorrdd
Other genes affect the pattern of colour or modify the final colour. Some of these genes are:
B = gives a blotch of colour in the throat of the bloom. The recessive "bb" produces flowers without a blotch. The trait appears to produce a darker or more intense version of the colour of the outer edges of the petals. Thus, you can get dark pink blotches on a lighter pink flower etc.
H = gives colour on the capitate hairs of the pistil. The recessive "hh" gives white or colourless hairs.
Genes F, I, B, and H are very closely linked and are usually inherited as a single unit. Therefore, many plants have pigmented flowers with at least medium intensity of color, and blotches in the throat, or have white flowers without blotches.
C = adds a co-pigment to the flower colour. This gene modifies the appearance of the colour, giving a bluish tint to the overall colour. Plants with the recessive "cc" combination have flowers that are "brighter" in appearance. In the Mauve-Rose-Salmon series, the dominant gene produces undesirable murky colours.
L = puts nectar guides in the flower tubes. The recessive "ll" produces flowers without the lines.
Y = puts a yellow central stripe in the flower tube. I suspect that the size of the yellow area changes with "YY" versus "Yy" plants. The recessive "yy" would produce flowers with no yellow in the flower tube.
Other genes are mentioned in the original articles,[43][44] but they appear to involve some rarely seen colour modifications. Genes for plant size, fragrance etc. were not mentioned in these articles.
The following is an adapted excerpt from the 1906 text "Hortus Veitchii":[45]
The first Streptocarpus to reach British gardens was Streptocarpus rexii. This species was sent to Kew in 1824 by Mr Bowie, who was His Majesty’s collector in South Africa. The plant was found on the estate of Mr George Rex, after whom it was named.
Following Streptocarpus rexii came Streptocarous polyantha from Natal. It was accidentally introduced to Kew in 1853 in material surrounding trunks of tree ferns sent from Natal by Captain Garden.
Streptocarpus gardeni, also introduced in 1853 from the same country was named for Captain Garden, who sent seeds to Kew.
In 1860, Mr Wilson Saunders sent a specimen to Kew, and it was eventually named Streptocarpus saundersii.
In 1882, the caulescent species, Streptocarpus kirkii, was sent to Kew by Sir John Kirk.
Streptocarpus caulescens, another caulescent species, followed in 1886.
In 1887, Streptocarpus parviflora (probably Streptocarpus parviflorus, and referred to hereafter as such) was raised from seed brought in from Grahamstown by Mr Watson of Kew.
A similar plant raised from seed by Mr Lynch of the Cambridge Botanic Gardens, was eventually named Streptocarpus lutea.
The next plant to be introduced, Streptocarpus dunnii, played an important role in the production of “beautiful hybrids” of the day. In 1884, seed was collected in the mountains of the Transvaal gold fields, and sent to Kew by Mr E. G. Dunn of Claremont, Cape Town. It was a unifoliate species with “rose or salmon red colour”. It first flowered at Kew in 1886.
In 1890, Streptocarpus galpini was introduced to Kew by Mr E Galpin, who found it on the “Bearded Man” peak that forms one of the boundaries of Swaziland.
Streptocarpus wendlandii was sent in 1887 from Transvaal to Naples to “Messrs Damman” (i.e. two or more men with the last name ‘Damman’ – possibly nurserymen). It first appeared in England at Kew in seed contained in soil attached to tree ferns from South Africa. It flowered at Kew in 1895.
A hybrid named “Streptocarpus × Dyeri” was raised at Kew by crossing Streptocarpus wendlandii with Streptocarpus dunii.
Streptocarpus faninii (not currently listed, could this perhaps be referring to Streptocarpus fanniniae?), is apparently noteworthy because of its contribution to many of the “more beautiful hybrids”.
Hortus Veitchii states that the first hybrid Streptocarpus recorded was “Streptocarpus × Greenii”, which was the progeny of S. saundersii and S. rexii. It was raised by Mr Charles Green, who was at the time the gardener to Sir George Mackay of Pendell Court. This specimen was apparently never widely grown and did not contribute to the “present garden race”.
The initial step towards the “beautiful forms” in cultivation at the time was taken by the Curator of Kew. He raised the hybrid “Streptocarpus × Kewensis” by crossing S. rexii and S. dunii. However, he had previously also raised S. parviflorus × S. rexii. A coloured plate of the progeny was published in 1886.
In 1887, another Kew-raised hybrid flowered. It was a hybrid of S. parviflorus and S. dunnii, and received the name of S. × Watsoni, after Mr Watson who raised the seed.
In 1887, two hybrids (S. × Kewensis and S. × Watsoni) were crossed with each other and their parents in all combinations. A host of progeny resulted with marked differences in colour, size, form and flower, and many were “decidedly attractive”. A selection of these were obtained by Heal, who crossed them with each other and with the red-flowered S. dunii. Many of these are now known as “Veitch’s Original Hybrids”. Breeding continued using these hybrids.
There are several societies and groups dedicated to Streptocarpus enthusiasts. Common activities include imparting knowledge, sharing plant material for propagation, and Streptocarpus shows. These societies are both large and small. Some of the groups are housed within larger Gesneriad groups.
Examples of Streptocarpus societies or groups:
Shows
In addition to the casual growing, private enthusiasm, or hybridizing, Streptocarpus make excellent show plants.
Flower shows are competitions where prizes are awarded for presenting outstanding, usually individual specimens.
Streptocarpus are shown in locations all around the world, either in Streptocarpus-exclusive shows, or as part of wider garden or Gesneriaceae shows.
Generally, to do well at shows, a specimen needs to have many perfect flowers, none faded or damaged; and many healthy, unblemished leaves. Streptocarpus flowers come from leaves, so more leaves means more flowers.[51]
Prizes may also be awarded for "uniqueness" of a specimen.
Displays
Displays are when a large group of plants are shown together, and prizes are awarded for the overall 'look' of the display.
Dibleys Nurseries, of Wales, have won over 100 Royal Horticultural Society gold medals for their Streptocarpus displays, including 25 Chelsea Flower Show gold medals.
![[Left] Normal Streptocarpus flower (zygomorphic), and [right] peloric Streptocarpus flower on the same plant.](http://en.wikipedia.org/wiki/File:Peloria_in_Streptocarpus.jpg)
[Left] Normal Streptocarpus flower (zygomorphic), and [right] peloric Streptocarpus flower on the same plant.
Asymmetric cotyledon development in Streptocarpus subgenus Streptocarpella
Streptocarpus 'Marlene' from above
Pink Streptocarpella flowers
Streptocarpus seed
A flower showing 'fantasy' patterning, Streptocarpus 'DS-Little Plushy Arctic Fox'
Streptocarpus seedling with Streptocarpus liliputana in recent ancestry
,_young_plant.JPG)
Streptocarpus confusus ssp confusus, young plant
Streptocarpus 'Anderson's Purple Delta'
Part of the Dibleys Streptocarpus display at the Chelsea Flower Show in May 2011
Extra petal anomaly in Streptocarpus 'Gloria'
_Streptocarpus_%27Kim%27_after_pre-winter_prune_showing_creeping_stems.JPG)
10-year-old (approx) Streptocarpus 'Kim' after pre-winter prune showing creeping stems
Side-on view of a Streptocarpus flower
An unopened Streptocarpus bud showing hairs, Streptocarpus 'Anderson's Nightway'
Streptocarpella 'Concord Blue'
A mature rosulate variety of Streptocarpus showing new winter abscission lines
Close-up of a Streptocarpus leaf showing winter abscission line
Left: A normal zygomorphic Streptocarpus flower. Right: An aberrant peloric Streptocarpus flower. Both of these flowers appeared on the Streptocarpus hybrid 'Anderson's Crows' Wings'.
Root plantlet of Streptocarpus 'Dale's Polar Lava'
Root plantlet on Streptocarpus 'Gloria'
_(9600930518).jpg)
{{cite web}}: CS1 maint: url-status (link) {{cite web}}: Check |url= value (help) Streptocarpus ("twisted fruit" from Greek στρεπτός (streptos) "twisted" and καρπός (carpos) "fruit") is an Afrotropical genus of flowering plants in the family Gesneriaceae. The genus is native to Afromontane biotopes from central, eastern and southern Africa, including Madagascar and the Comoro Islands. The flowers are five-petalled, salverform tubes, almost orchid-like in appearance, and hover or arch over the plant, while the pointed, elongate fruit is of a helical form similar to that of the "tusk" of a narwhal. In the wild, species can be found growing on shaded rocky hillsides or cliffs, on the ground, in rock crevices, and almost anywhere the seed can germinate and grow. For the home, there are now many hybrids of various colours and forms available.
Although generally referred to simply as "Streptocarpus" or "Streps", the common name for subgenus Streptocarpus is Cape primrose, referring to the nativity of several species to South Africa and their superficial resemblance to the unrelated genus Primula. The common name for subgenus Streptocarpella is nodding violet. Streptocarpus sect. Saintpaulia ("African violet") is a separate section within Streptocarpus subgenus Streptocarpella.
DNA studies have shown that, despite not having a twisted fruit, African violets evolved from within the Tanzanian Streptocarpus subgenus Streptocarpella.
There are a few Asian species that have recently been removed from the genus, most notably Streptocarpus orientalis, now reclassified as Damrongia orientalis. Molecular systematics has shown conclusively that they are not true Streptocarpus.
Streptocarpus es un género de plantas perteneciente a la familia Gesneriaceae. Comprende 230 especies descritas y de estas, solo 134 aceptadas.[1]
Está estrechamente relacionado con el género Saintpaulia. Su nombre común es Cabo Primrose, refiriéndose al nombre de varias especies de Sudáfrica y su semejanza superficial al género Primula. El género es nativo de partes de África y Madagascar (con unas pocas especies extrañas en Asia, que probablemente no tienen cabida en el género). Las plantas a menudo crecen en la sombra de las laderas rocosas o acantilados. Se encuentran cada vez más sobre el terreno, grietas de rocas, y la semilla puede germinar y crecer casi en cualquier parte. A
El género se define por tener un fruto retorcido en espiral (de ahí el nombre de "Streptocarpus"), aunque este carácter se encuentra también en algunos otros géneros de Gesneriaceae del Viejo Mundo .
El género fue descrito por John Lindley y publicado en Journal of Botany, British and Foreign 49: 188. 1911.[2]
Streptocarpus: nombre genérico que deriva del idioma griego στρεπτός, streptos = "retorcido", y καρπός, "karpos" = "fruto", aludiendo a lo retorcido de sus cápsulas.
Subgénero Streptocarpella:
Streptocarpus es un género de plantas perteneciente a la familia Gesneriaceae. Comprende 230 especies descritas y de estas, solo 134 aceptadas.
Soilikit (Streptocarpus) on gesneriakasvien heimoon kuuluva suku.
Kukkien värejä ovat valkoisen, sinisen ja punaisen sävyt. Alasuvun Streptocarpella lajeilla on pysty varsi. Alasuvun Streptocarpus lajeilla puolestaan on erittäin lyhyet varret ja lehdet ovat tyvessä ruusukkeena.
Soilikit ovat lähtöisin Etelä-Afrikasta. Luonnonvaraisia lajeja ovat S. polyanthus ja S. wendlandii.
Soilikkeja käytetään huonekasveina.[1] Kasvit viihtyvät valoisalla ja lämpimällä kasvupaikalla. Tosin talvella lämpöä ei tarvitse olla paljoa. Ilmankosteuden tulee olla korkea. Lisäämiseen käytetään lehtipistokkaita, jotka leikataan halki ennen istuttamista.
Soilikit (Streptocarpus) on gesneriakasvien heimoon kuuluva suku.
Streptocarpus est un genre de plantes de la famille des Gesneriaceae dans la classification phylogénétique.
Selon BioLib (24 juillet 2017)[2] :
Selon BioLib (24 juillet 2017)[2] :
Selon Catalogue of Life (24 juillet 2017)[3] :
Selon GRIN (24 juillet 2017)[4] :
Selon ITIS (24 juillet 2017)[5] :
Selon NCBI (24 juillet 2017)[6] :
Selon The Plant List (24 juillet 2017)[7] :
Selon Tropicos (24 juillet 2017)[1] (Attention liste brute contenant possiblement des synonymes) :
Streptocarpus est un genre de plantes de la famille des Gesneriaceae dans la classification phylogénétique.
Wšědny streptokarpus je rostlina ze swójby gesnerijowych rostlinow (łaćonsce: Streptocarpus rexii, Gesneriaceae).
Wšědny streptokarpus je rostlina ze swójby gesnerijowych rostlinow (łaćonsce: Streptocarpus rexii, Gesneriaceae).
Streptokarpas (lot. Streptocarpus) – gesnerijinių (Gesneriaceae) šeimos augalų gentis, kuri labai artima sanpaulijoms.
Auga Afrikoje, Madagaskare, kelios rūšys Azijoje.
Gentyje yra apie 155 rūšys.
Streptokarpas (lot. Streptocarpus) – gesnerijinių (Gesneriaceae) šeimos augalų gentis, kuri labai artima sanpaulijoms.
Auga Afrikoje, Madagaskare, kelios rūšys Azijoje.
Gentyje yra apie 155 rūšys.
Multimedia w Wikimedia Commons Skrętnik (Streptocarpus) – rodzaj roślin zielnych z rodziny ostrojowatych. Blisko spokrewniony z powszechnie w Polsce znanym rodzajem sępolia, którego kultywary są uprawiane jako ozdobne rośliny doniczkowe. Wyróżnionych zostało około 155 gatunków występujących w południowej i południowo-wschodniej Afryce oraz na Madagaskarze. Jest też kilka gatunków z Azji Południowo-Wschodniej, jednak ich przynależność taksonomiczna jest dyskusyjna[3]. Skrętniki rosną zarówno jako epifity jak i na skałach, zboczach wzgórz i w ściółce leśnej, wszędzie tam gdzie zdołają wykiełkować ich nasiona.
Liście mogą być owalne i długie, wyrastające bezpośrednio z bezłodygowej rozety jako liście odziomkowe (w podrodzaju Streptocarpus) lub krótsze, owalne lub okrągłe, osadzone na wiotkich lub płożących się łodygach (w podrodzaju Streptocarpella)[4]. Niektóre z gatunków nie wytwarzają w ogóle liści, a jedynie jeden rozrośnięty liścień, który żywi roślinę aż do wydania przez nią owoców, po czym cała roślina zamiera[4]. Są to gatunki monokarpiczne, natomiast gatunki posiadające liście są z reguły polikarpicznymi bylinami[5]. Kwiaty są pojedyncze, kielichowate, z płatkami zrośniętymi u nasady w rurkę. Wyrastają po jednym lub kilka na cienkich, bezlistnych pędach. U gatunków wytwarzających stały liścień liczba kwiatów na jednym kwiatostanie jest znacznie większa. Kwiaty są najczęściej fioletowego, niebieskiego lub białego koloru, choć zdarzają się również czerwone czy różowe, a hodowcy uzyskali wiele różnych odmian i hybryd wielokolorowych. Owoce formują się w formie skręconych torebek nasiennych, od czego wzięła się zarówno łacińska i polska nazwa tych roślin[6].
Rośliny ozdobne. Chociaż w Polsce nie są tak popularne jak spokrewnione z nimi sępolie, to jednak w Europie cieszą się sporym zainteresowaniem hodowców, którzy począwszy od XIX wieku z wyselekcjonowanych gatunków uzyskali wiele odmian i kultywarów[6]. W cieplejszym klimacie gatunki z podrodzaju Streptocarpella są wykorzystywane jako ściółka, a w domach jako rośliny wiszące[4].
Należy do rodziny ostrojowatych (Gesneriaceae) Dumort., która jest kladem w obrębie rzędu jasnotowców (Lamiales) Bromhead z grupy astrowych spośród roślin okrytonasiennych[1].
Gromada okrytonasienne (Magnoliophyta Cronquist), podgromada Magnoliophytina Frohne & U. Jensen ex Reveal, klasa Rosopsida Batsch, podklasa jasnotowe (Lamiidae Takht. ex Reveal), nadrząd Lamianae Takht., rząd jasnotowce (Lamiales Bromhead ), rodzina ostrojowate (Gesneriaceae Dumort.), plemię Streptocarpeae Fritsch in Engl. & Prantl, rodzaj Streptocarpus Lindl[7].
Podrodzaj Streptocarpus:
Podrodzaj Streptocarpella:
Skrętnik (Streptocarpus) – rodzaj roślin zielnych z rodziny ostrojowatych. Blisko spokrewniony z powszechnie w Polsce znanym rodzajem sępolia, którego kultywary są uprawiane jako ozdobne rośliny doniczkowe. Wyróżnionych zostało około 155 gatunków występujących w południowej i południowo-wschodniej Afryce oraz na Madagaskarze. Jest też kilka gatunków z Azji Południowo-Wschodniej, jednak ich przynależność taksonomiczna jest dyskusyjna. Skrętniki rosną zarówno jako epifity jak i na skałach, zboczach wzgórz i w ściółce leśnej, wszędzie tam gdzie zdołają wykiełkować ich nasiona.
Streptocarpus é um género botânico pertencente à família Gesneriaceae.[1]
Este gênero apresenta 211 espécies:
Streptocarpus Lindl.
Streptocarpus é um género botânico pertencente à família Gesneriaceae.
Kornettblomssläktet (Streptocarpus) är ett växtsläkte i familjen gloxiniaväxter med cirka 135 arter från Afrika, Madagaskar och Asien. Några odlas som krukväxter i Sverige.
Kornettblomssläktet (Streptocarpus) är ett växtsläkte i familjen gloxiniaväxter med cirka 135 arter från Afrika, Madagaskar och Asien. Några odlas som krukväxter i Sverige.
Streptocarpus Lindl.
Виды
Стрептока́рпус (лат. Streptocarpus) — род красивоцветущих травянистых розеточных растений семейства Геснериевые.
Один куст взрослого стрептокарпуса может нести около сотни цветков одновременно. Семенные коробочки при созревании скручиваются. Отсюда название (по-гречески streptos — «скрученный», karpos — «коробочка»).
Растения родом с Мадагаскара и из Южной Африки. Там, в тропических и субтропических лесах, на склонах гор на определённой высоте над уровнем моря, где не бывает очень высокой температуры, произрастают более 100 природных видов стрептокарпусов. Стрептокарпусы чаще литофиты, реже — эпифиты. Условно стрептокарпусы можно разделить на ксерофитные виды и лесные, в зависимости от среды обитания.
Сейчас выведено больше тысячи гибридов этих растений.
По информации базы данных The Plant List, род включает 134 вида[2]. Некоторые из них:
Стрептока́рпус (лат. Streptocarpus) — род красивоцветущих травянистых розеточных растений семейства Геснериевые.
Один куст взрослого стрептокарпуса может нести около сотни цветков одновременно. Семенные коробочки при созревании скручиваются. Отсюда название (по-гречески streptos — «скрученный», karpos — «коробочка»).
Растения родом с Мадагаскара и из Южной Африки. Там, в тропических и субтропических лесах, на склонах гор на определённой высоте над уровнем моря, где не бывает очень высокой температуры, произрастают более 100 природных видов стрептокарпусов. Стрептокарпусы чаще литофиты, реже — эпифиты. Условно стрептокарпусы можно разделить на ксерофитные виды и лесные, в зависимости от среды обитания.
Сейчас выведено больше тысячи гибридов этих растений.
提示：本条目的主题不是海角櫻草。海角櫻草属（学名：Streptocarpus），又名菫蘭属或旋果苣苔属，為苦苣苔科下的雙子葉開花植物。其原生於非洲中部、東部、與南部的山區，亦分佈於馬達加斯加與葛摩群島[1]。此屬共有176種並分為兩個亞屬Streptocarpus與Streptocarpella，其成員包含園藝常見的非洲堇、菫蘭等[2]。在其原生地非洲，這些植物通常生長在有陰影遮蔽的山坡或石壁上。而作為一種常見園藝植物，現在已有許多園藝雜交種的出現[3]。
在型态特徵上，此属植物的花均为五瓣，花冠為高腳碟狀，近似兰花的型态自花序垂挂而下。而其名海角樱草又显示着植物的叶部型态与报春花科的樱草相似（英文俗名：Cape Primrose 即 好望角报春花）。此属原被定义的分类特徵为「具有螺旋型果荚」（属名源自拉丁文strepto = 旋型，carpus = 果实），但后来发现此特徵广泛分佈于其他旧世界的苦苣苔科物种上。
DNA分子親緣關係研究显示，虽然不具有螺旋型的果荚，但园艺植物非洲堇可能演化自坦尚尼亚的Streptocarpella亚属，而主張將非洲堇屬降級為Streptocarpella亞屬的一個組──非洲堇組（sect. Saintpaulia）。[2][4]
旋果苣苔的名字来源于她长长的，螺旋状的果莢。Streptocarpus源自希腊语στρεπτός（streptos）是旋转的意思，而καρπός（karpos）是果实的意思。
除園藝使用上，海角櫻草屬的植物亦因其花的多樣性與特殊的生長型態而被廣泛研究[5][6][7][8][9][10][11][2]，其特殊性包含二片子葉的不等大發育、無主莖的生長型、以及離層線的產生。
雖然是雙子葉植物，但海角櫻草屬的植物在萌芽後，兩片子葉會不等速的生長，形成子葉不等大的現象（Anisocotyly）[5][6][7][9][11]。其中一片會持續延伸膨大而外觀與真葉相似；另一片則會停止生長至最後老化脫落。此特徵普遍存在於舊世界的苦苣苔物種中。
依其葉片數量與莖部發育，海角櫻草屬植物可被略分為三種生長型 （Growth form）[5][6][7][8][10][9][11][2]：
無主莖多葉型（Acaulescent, rosulate），此生長型不具有明顯的莖，而新生葉片是自膨大後的子葉基部長出，形成多葉環狀外觀（Rosette）。
無主莖單葉型 （Acaulescent, unifoliate），此生長型不具明顯的莖，亦不生長新的葉片，唯一的葉片就是膨大的大子葉。在某些物種中（例：S. grandis）此子葉甚至可以生長至80公分長。
有主莖型 （Caulescent），與其他植物相同，具有明顯的根、莖、葉構造。
S. rexii新葉自大子葉基部長出
S. kentaniensis 無主莖多葉生長型近照
海角櫻草中的單葉品種S. grandis
在某些多年生的單葉品種（及部分的多葉品種）中可看到此類植物獨有的「離層線」（Abscission line）[5] 現象。冬天時，這些海角櫻草會在葉片中間形成一條「離層線」，離層線以外的區域（abscission zone）會老化乾枯，但離層線以內的葉片會維持長綠。此與大多數植物中，葉片是直接自葉梗基部斷裂有所區別。
離層線：S. molweniensis中觀察到的離層線現象，自葉片中間生成，使遠離植物體側的葉片會自然老化斷裂
此屬的模式物種為海角櫻草Streptocarpus rexii。下列部分的代表性物種[12]：
同一顆植株上，（左）兩側對稱與（右）輻射對稱的花
Streptocarpella亞屬物種的子葉不等大發育
S. 'Marlene'
粉紅色系的花
種子近照
園藝種'fantasy'花色, Streptocarpus 'DS-Little Plushy Arctic Fox'
S. liliputana幼苗
S. confusus ssp. confusus
園藝種Streptocarpus 'Anderson's Purple Delta'
2011年5月 Chelsea Flower Show, Dibleys Streptocarpus展示
園藝種Streptocarpus 'Gloria'六瓣突變花
生長約十年的園藝種 Streptocarpus 'Kim'的匍匐莖
花朵側照
園藝種Streptocarpus 'Anderson's Nightway'花苞
園藝種Streptocarpella 'Concord Blue'
多葉生長型植物上的離層線
離層線近照
（左）兩側對稱與（右）輻射對稱的花。園藝種Streptocarpus hybrid 'Anderson's Crows' Wings'
園藝種Streptocarpus 'Dales Polar Lava'幼苗
園藝種Streptocarpus 'Gloria'幼苗
,_young_plant.JPG)
_Streptocarpus_%27Kim%27_after_pre-winter_prune_showing_creeping_stems.JPG)
|access-date=中的日期值 (帮助); 使用|accessdate=需要含有|url= (帮助) 海角櫻草属（学名：Streptocarpus），又名菫蘭属或旋果苣苔属，為苦苣苔科下的雙子葉開花植物。其原生於非洲中部、東部、與南部的山區，亦分佈於馬達加斯加與葛摩群島。此屬共有176種並分為兩個亞屬Streptocarpus與Streptocarpella，其成員包含園藝常見的非洲堇、菫蘭等。在其原生地非洲，這些植物通常生長在有陰影遮蔽的山坡或石壁上。而作為一種常見園藝植物，現在已有許多園藝雜交種的出現。
在型态特徵上，此属植物的花均为五瓣，花冠為高腳碟狀，近似兰花的型态自花序垂挂而下。而其名海角樱草又显示着植物的叶部型态与报春花科的樱草相似（英文俗名：Cape Primrose 即 好望角报春花）。此属原被定义的分类特徵为「具有螺旋型果荚」（属名源自拉丁文strepto = 旋型，carpus = 果实），但后来发现此特徵广泛分佈于其他旧世界的苦苣苔科物种上。
DNA分子親緣關係研究显示，虽然不具有螺旋型的果荚，但园艺植物非洲堇可能演化自坦尚尼亚的Streptocarpella亚属，而主張將非洲堇屬降級為Streptocarpella亞屬的一個組──非洲堇組（sect. Saintpaulia）。
