''Streptocarpus'' sect. ''Saintpaulia'' is a section within ''

Streptocarpus ''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 ...

'' subgenus ''Streptocarpella'' consisting of about ten species of

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

perennial flowering plants in the family Gesneriaceae, native to Tanzania and adjacent southeastern Kenya in eastern tropical Africa. The section was previously treated as a separate genus, ''Saintpaulia'', but

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

studies showed that it was nested within the genus ''Streptocarpus''. Species and cultivars are commonly called African violets (although they are not closely related to true

violets Violet identifies various plant taxa, particularly species in the genus ''Viola'', within which the common violet is the best known member in Eurasia and the common blue violet and common purple violet are the best known members in North America ...

) or saintpaulias. They are commonly sold as house plants. Several of the species and subspecies of the section are endangered, and many more are threatened, as their native

cloud forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud c ...

habitats are cleared for agriculture. The conservation status of ''

Streptocarpus ionanthus ''Streptocarpus ionanthus'' ( synonym ''Saintpaulia ionantha'') is a species of '' Streptocarpus'' in the section '' Saintpaulia'', commonly known as an African violet. It is native to eastern and southwestern Tanzania Tanzania (; ), off ...

'' has been classed as near-threatened.

Description

Saintpaulias, which grow from 6-15 cm tall, can be anywhere from 6-30 cm wide. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are rounded to oval, 2.5-8.5 cm long with a 2-10 cm petiole, finely

hairy Hairy may refer to: * people or animals covered in hairs or fur * plants covered in trichomes * insects covered in setae * people nicknamed "the Hairy" * Hairy (gene) See also * Hairies, a fictional people * Haerye ''Hunminjeongeum Haerye'' ...

, 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. The plants get their common name "African violet" from their superficial resemblance to true

violet Violet may refer to: Common meanings * Violet (color), a spectral color with wavelengths shorter than blue * One of a list of plants known as violet, particularly: ** ''Viola'' (plant), a genus of flowering plants Places United States * Viol ...

s (''Viola'', family

Violaceae Violaceae is a family of flowering plants established in 1802, consisting of about 1000 species in about 25 genera. It takes its name from the genus ''Viola'', the violets and pansies. Older classifications such as the Cronquist system placed t ...

Taxonomy

This group of plants has lived in the biodiverse Eastern Arc Usambara mountains in Tanga province for millions of years. The name in the local Kisambaa language is Dughulushi. The Germans officially colonialized this area from about 1885, and shortly before this, Baron

Walter von Saint Paul-Illaire Walter von Saint Paul-Illaire or Adalbert Emil Walter Le Tanneux von Saint Paul-Illaire (born January 12, 1860 in Berlin ; † December 12, 1940 ibid) was a German colonial official in East Africa. He hailed from the noble family of Le Tanneux von ...

(1860–1940) was made district commissioner of Tanga province,

Tanganyika Tanganyika may refer to: Places * Tanganyika Territory (1916–1961), a former British territory which preceded the sovereign state * Tanganyika (1961–1964), a sovereign state, comprising the mainland part of present-day Tanzania * Tanzania Main ...

(now Tanzania) in Africa. He used to enjoy walking in the rainforest and they reminded him of the violets back home. He called them Usambaraveilchen (Usambara violets). In 1892 he sent seeds back to his father, who gave them to an amateur botanist, Hermann Wendland, in Germany. Wendland named the genus for Saint Paul-Illaire and his father. Two British plant enthusiasts, Sir John Kirk and the 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. Revisions of the genus by

B.L. Burtt Bachelor of Laws ( la, Legum Baccalaureus; LL.B.) is an undergraduate law degree in the United Kingdom and most common law jurisdictions. Bachelor of Laws is also the name of the law degree awarded by universities in the People's Republic of Chi ...

expanded the genus to approximately 20 species. Following studies which showed most of the species to be very poorly differentiated, both genetically and morphologically, the number of species was reduced to six in a 2006 treatment, with the majority of former species reduced to subspecies under ''S. ionantha''. In 2009, 9 species, 8

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

, and 2 varieties were recognized. A

study in 2015 confirmed previous studies showing that species placed in ''Saintpaulia'' were deeply embedded within the genus ''Streptocarpus'', supporting the transfer of all ''Saintpaulia'' species to ''Streptocarpus'' in 2012. Former ''Saintpaulia'' species did form a monophyletic group, and were placed in section ''Saintpaulia'' of ''Streptocarpus'' subgenus ''Streptocarpella''.

Species

All the species previously placed in the genus ''Saintpaulia'' are now placed in ''Streptocarpus'' section ''Saintpaulia''. Ten species were recognized, . * ''

Streptocarpus afroviola ''Streptocarpus afroviola'', synonym ''Saintpaulia pusilla'', is a species of flowering plant in the family Gesneriaceae, native to Tanzania. It was first described in 1900 by Adolf Engler as ''Saintpaulia pusilla''. The former genus ''Saintpau ...

'' Christenh. * ''

Streptocarpus albus ''Streptocarpus albus'' is a species of flowering plant in the family Gesneriaceae, native to Tanzania. It was first described in 1933 as ''Saintpaulia alba''. It is found in the Uluguru and Nguru mountains of Tanzania. References albus Al ...

'' (E.A.Bruce) I.Darbysh. * ''

Streptocarpus brevipilosus ''Streptocarpus brevipilosus'' is a species of flowering plant in the family Gesneriaceae, native to Tanzania. It was first described in 1964 as ''Saintpaulia brevipilosa''. The former genus ''Saintpaulia'' was reduced to ''Streptocarpus'' s ...

'' (B.L.Burtt) Mich.Möller & Haston * ''

Streptocarpus goetzeanus ''Streptocarpus goetzeanus'', synonym ''Saintpaulia goetzeana'', is a species of ''Streptocarpus'' in the section '' Saintpaulia'', commonly known as an African violet. It is a small, flowering plant that is used widely in home horticulture. ''S. ...

'' (Engl.) Christenh. * ''

Streptocarpus inconspicuus ''Streptocarpus inconspicuus'', synonym ''Saintpaulia inconspicua'', is a species of ''Streptocarpus'' in the section '' Saintpaulia''. It is a rare African violet, found in the Uluguru Mountains in Tanzania, East Africa. It was first formally de ...

'' (B.L.Burtt) Christenh. * ''

'' (H.Wendl.) Christenh. * ''

Streptocarpus nitidus ''Streptocarpus nitidus'' is a species of flowering plant in the family Gesneriaceae, native to Tanzania. It was first described in 1958 as ''Saintpaulia nitida''. The former genus ''Saintpaulia'' was reduced to ''Streptocarpus'' sect. ''Sai ...

'' (B.L.Burtt) Mich.Möller & Haston * ''

Streptocarpus shumensis ''Streptocarpus shumensis'', synonym ''Saintpaulia shumensis'', is a species of ''Streptocarpus'' in the section '' Saintpaulia''. It is endemic to Shume in the west Usambara Mountains and also from the northern Nguru Mountains, both in Tanzania ...

'' (B.L.Burtt) Christenh. * ''

Streptocarpus teitensis ''Streptocarpus teitensis'', synonym ''Saintpaulia teitensis'', is a species of ''Streptocarpus'' in the section ''Saintpaulia ''Streptocarpus'' sect. ''Saintpaulia'' is a section within ''Streptocarpus'' subgenus ''Streptocarpella'' consis ...

'' (B.L.Burtt) Christenh. * ''

Streptocarpus ulugurensis ''Streptocarpus ulugurensis'' is a species of flowering plant in the family Gesneriaceae. It is an herbaceous perennial endemic to the Uluguru Mountains of Tanzania. ''Streptocarpus ulugurensis'' is known from a single location of only five squ ...

'' (Haston) Haston Formerly recognized ''Saintpaulia'' species and infraspecies are listed below with their accepted name in ''Streptocarpus''. *''Saintpaulia alba'' E.A.Bruce = ''

'' (E.A.Bruce) I.Darbysh. *''Saintpaulia amaniensis'' E.P.Roberts = ''

'' subsp. ''grotei'' (Engl.) Christenh. *''Saintpaulia brevipilosa'' B.L.Burtt = ''

'' (B.L.Burtt) Mich.Möller & Haston *''Saintpaulia confusa'' B.L.Burtt = ''

'' subsp. ''grotei'' (Engl.) Christenh. *''Saintpaulia difficilis'' B.L.Burtt = ''

'' subsp. ''grotei'' (Engl.) Christenh. *''Saintpaulia diplotricha'' B.L.Burtt = ''

'' var. ''diplotrichus'' (B.L.Burtt) Christenh. *''Saintpaulia goetzeana'' Engl. = ''

'' (Engl.) Christenh. *''Saintpaulia grandifolia'' B.L.Burtt = ''

'' subsp. ''grandifolius'' (B.L.Burtt) Christenh. *''Saintpaulia grotei'' Engl. = ''

ionanthus'' subsp. ''grotei'' (Engl.) Christenh. *''Saintpaulia inconspicua'' B.L.Burtt = ''

'' (B.L.Burtt) Christenh. *''Saintpaulia intermedia'' B.L.Burtt = ''

'' subsp. ''pendulus'' (B.L.Burtt) Christenh. *''Saintpaulia ionantha'' H.Wendl. = ''

'' (H.Wendl.) Christenh. **''Saintpaulia ionantha'' subsp. ''grandifolia'' (B.L.Burtt) I.Darbysh. = ''Streptocarpus ionanthus'' subsp. ''grandifolius'' (B.L.Burtt) Christenh. **''Saintpaulia ionantha'' subsp. ''grotei'' (Engl.) I.Darbysh. = ''Streptocarpus ionanthus'' subsp. ''grotei'' (Engl.) Christenh. **''Saintpaulia ionantha'' subsp. ''mafiensis'' I.Darbysh. & Pócs = ''Streptocarpus ionanthus'' subsp. ''mafiensis'' (I.Darbysh. & Pócs) Christenh. **''Saintpaulia ionantha'' subsp. ''nitida'' (B.L.Burtt) I.Darbysh. = ''

'' (B.L.Burtt) Mich.Möller & Haston **''Saintpaulia ionantha'' subsp. ''occidentalis'' (B.L.Burtt) I.Darbysh. = ''Streptocarpus ionanthus'' subsp. ''occidentalis'' (B.L.Burtt) Christenh. **''Saintpaulia ionantha'' subsp. ''orbicularis'' (B.L.Burtt) I.Darbysh. = ''Streptocarpus ionanthus'' subsp. ''orbicularis'' (B.L.Burtt) Christenh. **''Saintpaulia ionantha'' subsp. ''pendula'' (B.L.Burtt) I.Darbysh. = ''Streptocarpus ionanthus'' subsp. ''pendulus'' (B.L.Burtt) Christenh. **''Saintpaulia ionantha'' subsp. ''rupicola'' (B.L.Burtt) I.Darbysh.. = ''Streptocarpus ionanthus'' subsp. ''rupicola'' (B.L.Burtt) Christenh. **''Saintpaulia ionantha'' subsp. ''velutina'' (B.L.Burtt) I.Darbysh. = ''Streptocarpus ionanthus'' subsp. ''velutinus'' (B.L.Burtt) Christenh. **''Saintpaulia ionantha'' var. ''diplotricha'' (B.L.Burtt) I.Darbysh. = ''Streptocarpus ionanthus'' var. ''diplotrichus'' (B.L.Burtt) Christenh. *''Saintpaulia kewensis'' C.B.Clarke = ''

'' (H.Wendl.) Christenh. *''Saintpaulia magungensis'' E.P.Roberts = ''

'' subsp. ''grotei'' (Engl.) Christenh. **''Saintpaulia magungensis'' var. ''occidentalis'' B.L.Burtt = ''Streptocarpus ionanthus'' subsp. ''occidentalis'' (B.L.Burtt) Christenh. *''Saintpaulia nitida'' B.L.Burtt = ''

'' (B.L.Burtt) Mich.Möller & Haston *''Saintpaulia orbicularis'' B.L.Burtt = ''

'' subsp. ''orbicularis'' (B.L.Burtt) Christenh. *''Saintpaulia pendula'' B.L.Burtt = ''

'' subsp. ''pendulus'' (B.L.Burtt) Christenh. *''Saintpaulia pusilla'' Engl. = ''

'' Christenh. *''Saintpaulia rupicola'' B.L.Burtt = ''

'' subsp. ''rupicola'' (B.L.Burtt) Christenh. *''Saintpaulia shumensis'' B.L.Burtt = ''

'' (B.L.Burtt) Christenh. *''Saintpaulia teitensis'' B.L.Burtt = ''

'' (B.L.Burtt) Christenh. *''Saintpaulia tongwensis'' B.L.Burtt = ''

'' (H.Wendl.) Christenh. *''Saintpaulia ulugurensis'' Haston = ''

'' (Haston) Haston *''Saintpaulia velutina'' B.L.Burtt = ''

'' subsp. ''velutinus'' (B.L.Burtt) Christenh. *''Saintpaulia watkinsii'' Haston = ''

'' var. ''watkinsii'' (Haston) Christenh.

Distribution

Saintpaulias are native to eastern tropical Africa. There is a concentration of species in the

Nguru mountains The Nguru Mountains are a mountain range in Morogoro Region, Tanzania, Africa. The Nguru Mountains are part of the Eastern Arc Mountains. The mountains are predominantly covered with rainforest, home to 83 species of birds (Romdal 2001) and Africa ...

of Tanzania.

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 ''

'' (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 The African Violet Society of America (AVSA) is an international society of plant enthusiasts who promote the cultivation of African violets (''Streptocarpus'' sect. ''Saintpaulia'' species and cultivars) as house plants. The Society hosts an an ...

is the

International Cultivar Registration Authority An International Cultivation Registration Authority (ICRA) is an organization responsible for ensuring that the names of plant cultivars and cultivar groups are defined and not duplicated. The ICRA system was established more 50 years ago, and op ...

for the section and its cultivars.

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. * Micro: less than 3 inches * Super-mini: 3 to 4 inches African violet (Saintpaulia)

* Mini: between 4 and 6 inches * Semi-mini: between 6 and 8–10 inches * Standard: between 8–10 and 12–16 inches * Large/Giant: over 12–16 inches

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 A vacuole () is a membrane-bound organelle which is present in plant and fungal cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic mol ...

collapse in the palisade mesophyll cells.

Propagation

African violets are commonly propagated asexually. Plants can be divided into smaller daughter plants or even grown from leaf cuttings. Growing African violets from seed is rare and most commercially available plants are produced from cuttings and tissue culture.

Flowering

The African violet is a day-neutral plant regarding flower development.

In culture

African violets have become a traditional gift in the developed world. They are often offered for sale at holidays. They are a popular house plant in many countries, as they can flower during most of the year and are fairly durable to neglect.

References

External links

* *
African Violet Society of America websiteAfrican Violet Society of Canada websiteBaby Violets - African Violet Houseplants
{{Authority control Afromontane flora Endemic flora of Tanzania Flora of East Tropical Africa Garden plants of Africa House plants Plant sections