Streptocarpus sect. Saintpaulia: Difference between revisions
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==Characteristics== |
==Characteristics== |
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| ⚫ | Saintpaulias grow from 6–15 cm tall and can be anywhere from 6–30 cm wide. The [[leaves]] are rounded to oval, 2.5–8.5 cm long with a 2–10 cm [[petiole]], finely [[trichome|hairy]], and have a fleshy texture. The [[flower]]s are 2–3 cm in diameter, with a five-lobed velvety corolla ("petals"), and grow in clusters of 3–10 or more on slender stalks called peduncles. Wild species can have violet, purple, pale blue, or white [[flowers]]. |
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| ⚫ | Saintpaulias grow from 6–15 cm tall and can be anywhere from 6–30 cm wide. The [[leaves]] are rounded to oval, 2.5–8.5 cm long with a 2–10 cm [[petiole]], finely [[trichome|hairy]], and have a fleshy texture. The [[flower]]s are 2–3 cm in diameter, with a five-lobed velvety corolla ("petals"), and grow in clusters of 3–10 or more on slender stalks called peduncles. Wild species can have violet, purple, pale blue, or white [[flowers]].{{cn}} |
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===Sizes=== |
===Sizes=== |
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* Standard: between 8-10 to 12-16 inches |
* Standard: between 8-10 to 12-16 inches |
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* Large/Giant: over 12-16 inches |
* Large/Giant: over 12-16 inches |
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==Growth== |
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{{expand section|nodes and internodes, adventitious roots, growing from seed, crown|date=August 2013}} |
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===Temperature=== |
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Saintpaulias are highly sensitive to temperature changes, especially rapid leaf cooling. Spilling cold water on African violet leaves causes discoloration. This is thought to be because rapid leaf cooling causes [[cell vacuole]] collapse in the [[palisade mesophyll]] cells.<ref name="Plos—Vacuole collapse">{{cite journal|last=Kadohama|first=Noriaki|coauthors=Tatsuaki Goh, Miwa Ohnishi, Hidehiro Fukaki, Tetsuro Mimura,Yoshihiro Suzuki|title=Sudden Collapse of Vacuoles in Saintpaulia sp. Palisade Cells Induced by a Rapid Temperature Decrease|journal=PLoS One|year=2013|month=February|volume=8|issue=2|doi=10.1371/journal.pone.0057259|url=http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0057259}}</ref> |
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===Propagation=== |
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African violets are commonly [[Plant propagation|propagated]] [[asexually]]. Plants can be divided into smaller daughter plants or even grown from leaf cuttings.<ref name="Growing African violets">{{cite web|last=Thomas|first=Paul A|title=Growing African Violets|url=http://www.caes.uga.edu/publications/pubDetail.cfm?pk_ID=6342|publisher=CAES Publications|accessdate=11 August 2013}}</ref> |
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==Distribution== |
==Distribution== |
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Revision as of 19:03, 11 August 2013
| Streptocarpus sect. Saintpaulia | |
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| a Saintpaulia ionantha plant | |
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| Genus: | Saintpaulia |
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Saintpaulias, commonly known as African violets, are a genus of 6–20 species of herbaceous perennial flowering plants in the family Gesneriaceae, native to Tanzania and adjacent southeastern Kenya in eastern tropical Africa. Typically the African violet is a common household indoor plant but can also be an outdoor plant. Several of the species and subspecies are endangered, and many more are threatened, due to their native cloud forest habitats being cleared for agriculture.
Characteristics
![[icon]](/wiki/File:Wiki_letter_w_cropped.svg){kind=small} | This section needs expansion with: plant structure. You can help by adding to it. (August 2013) |
Saintpaulias grow from 6–15 cm tall and can be anywhere from 6–30 cm wide. The leaves are rounded to oval, 2.5–8.5 cm long with a 2–10 cm petiole, finely hairy, and have a fleshy texture. The flowers are 2–3 cm in diameter, with a five-lobed velvety corolla ("petals"), and grow in clusters of 3–10 or more on slender stalks called peduncles. Wild species can have violet, purple, pale blue, or white flowers.[citation needed]
Sizes
Plants can be classified as one of several sizes based on its above-ground diameter. Although the size per category is not set in stone, these are a general guideline.[1][2]
- Micro: less than 3 inches
- Super-mini: 3 to 4 inches
- Mini: between 4 to 6 inches
- Semi-mini: between 6 to 8-10 inches
- Standard: between 8-10 to 12-16 inches
- Large/Giant: over 12-16 inches
Growth
| This section needs expansion with: nodes and internodes, adventitious roots, growing from seed, crown. You can help by adding to it. (August 2013) |
Temperature
Saintpaulias are highly sensitive to temperature changes, especially rapid leaf cooling. Spilling cold water on African violet leaves causes discoloration. This is thought to be because rapid leaf cooling causes cell vacuole collapse in the palisade mesophyll cells.[3]
Propagation
African violets are commonly propagated asexually. Plants can be divided into smaller daughter plants or even grown from leaf cuttings.[4]
Distribution
Saintpaulias are native to eastern tropical Africa. There is a concentration of species in the Nguru mountains of Tanzania.
Taxonomy
The plants get their common name "African violet" from their superficial resemblance to true violets (Viola, family Violaceae).
The genus is named after Baron Walter von Saint Paul-Illaire (1860–1910), the district commissioner of Tanga province who discovered the plant in Tanganyika (now Tanzania) in Africa in 1892 and sent seeds back to his father, an amateur botanist in Germany. Two British plant enthusiasts, Sir John Kirk and Reverend W.E. Taylor, had earlier collected and submitted specimens to the Royal Botanic Gardens, Kew, in 1884 and 1887 respectively, but the quality of specimens was insufficient to permit scientific description at that time. The genus Saintpaulia, and original species S. ionantha, were scientifically described by H. Wendland in 1893.[5]
Revisions of the genus by B.L. Burtt expanded the genus to approximately 20 species. Due to recent studies which showed most of the species to be very poorly differentiated, both genetically and morphologically, the number of species has been reduced to six, with the majority of former species reduced to subspecies under S. ionantha, in a recent floristic treatment.[6] As of 2009, 9 species, 8 subspecies, and 2 varieties have been recognized.[7]
Old name vs. current name
- Saintpaulia amaniensis = S. ionantha ssp. grotei
- Saintpaulia brevipilosa = S. ionantha ssp. velutina
- Saintpaulia confusa = S. ionantha ssp. grotei
- Saintpaulia difficilis = S. ionantha ssp. grotei
- Saintpaulia diplotricha = S. ionantha ssp. ionantha var. diplotricha
- Saintpaulia grandifolia = S. ionantha ssp. grandifolia
- Saintpaulia grotei = S. ionantha ssp. grotei
- Saintpaulia intermedia = S. ionantha ssp. pendula
- Saintpaulia magungensis = S. ionantha ssp. grotei
- Saintpaulia magungensis var. minima = S. ionantha ssp. grotei
- Saintpaulia magungensis var. occidentalis = S. ionantha ssp. occidentalis
- Saintpaulia nitida = S. ionantha ssp. nitida
- Saintpaulia orbicularis = S. ionantha ssp. orbicularis
- Saintpaulia pendula = S. ionantha ssp. pendula
- Saintpaulia pendula var. kizarae = S. ionantha ssp. pendula
- Saintpaulia rupicola = S. ionantha ssp. rupicola
- Saintpaulia tongwensis = S. ionantha ssp. ionantha var. ionantha
- Saintpaulia velutina = S. ionantha ssp. velutina
The genus is most closely related to Streptocarpus, with recent phylogenetic studies suggesting it has evolved directly from subgenus Streptocarpella.
Cultivation
Saintpaulias are widely cultivated as house plants. Until recently, only a few of these species have been used in breeding programs for the hybrids available in the market; most available as house plants are cultivars derived from Saintpaulia ionantha (syn. S. kewensis). A wider range of species is now being looked at as sources of genes to introduce into modern cultivars.
The African Violet Society of America is the International Cultivar Registration Authority for the genus Saintpaulia and its cultivars.
In culture
African Violets have long been associated with mothers and motherhood. For this reason they have been a traditional gift to mothers in many cultures around the world.
References
- ^ "Grow-African-Violets.com". Retrieved 30 May 2013.
- ^ "The Violet Barn". Retrieved 30 May 2013.
- ^ Kadohama, Noriaki (2013). "Sudden Collapse of Vacuoles in Saintpaulia sp. Palisade Cells Induced by a Rapid Temperature Decrease". PLoS One. 8 (2). doi:10.1371/journal.pone.0057259.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help)CS1 maint: unflagged free DOI (link) - ^ Thomas, Paul A. "Growing African Violets". CAES Publications. Retrieved 11 August 2013.
- ^ Smithsonian World Checklist of the Gesneriaceae
- ^ Darbyshire (2006) Saintpaulia, pp. 50-72, in Beentjy & Ghazanfar (eds), Fl. Trop. East Africa
- ^ Pilon F (2012) Saintpaulia. The history and origin of the African Violet.
External links
